Method for establishing a combination therapy and corresponding pharmaceutical and nutritional combinations

Abstract

The present invention provides a method for establishing a combination therapy for modulating an intestinal microbiome and a pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, said combination comprising (i) a dietary fiber and / or a carbohydrate source and (ii) at least one bacterial strain identified in a method according to the invention.

Description

[0001]METHOD FOR ESTABLISHING A COMBINATION THERAPY AND CORRESPONDING PHARMACEUTICAL AND NUTRITIONAL COMBINATIONS FIELD OF THE INVENTION The present invention relates to the field of microbiology. It provides methods for establishing a combination therapy, pharmaceutical and nutritional combinations established by means of such method, compositions comprising probiotics forming part of such combinations, and uses thereof. BACKGROUND OF THE INVENTION Microbiomes are an essential contributor to the metabolic activity in the human gastrointestinal tract. The fermentation of otherwise indigestible nutritional components like dietary fibers relies on a complex interplay between the distributed metabolic activities across the individual bacterial members. Microbiome composition is diverse across individuals, and it has been suggested that this complexity might be reduced by describing microbiome composition not in terms of taxa but functions. Yet, which of the bacteria are responsible for which parts of the distributed metabolism and how they should be grouped together is insufficiently understood. An approach to map the different bacterial taxa that make up the gut microbiome onto the different functional niches of microbial carbohydrate fermentation have been described in the art (WO2022 / 023458). A presented approach uses in vitro measurements of bacterial growth and metabolic activity to identify which bacterial taxa are responsible for which metabolic function in the relevant complex context of whole human fecal microbiomes. Prebiotic compositions focusing on microbial functions which are key for the specific therapeutic target are known too (WO2020 / 079036). However, engraftment and stability of probiotic and prebiotic compositions in vivo are still not straightforward to achieve. Therefore, there is a need to design combinations of bacterial species and nutritional components which synergistically improve the colonization of the host’s microbiome, in order to prevent or treat intestinal dysbiosis and diseases or disorders related to detrimental conditions. SUMMARY OF THE INVENTION Here, the inventors identified ‘characteristic taxa’ for a panel of different carbon sources that are representative of the dietary components that are resistant to digestion by host enzymes. They then validated the predictive relevance of these characteristic taxa with data from a nutritional intervention study in humans. In a first aspect, the invention concerns a combination therapy comprising (i) at least one bacterial strain and (ii) at least one dietary fibre and / or carbohydrate source, wherein said combination therapy comprises: (a) at least one bacterial strain selected from the genera Lachnospira, UMGS1375, CAG-41, CAG-274 and UMGS1441, and (b) pectin (PE); (a) at least one bacterial strain selected from the genera Ruminococcus_D, Lachnospira, CAG-41, TF01-11, UMGS1441, Ruminiclostridium_E, Agathobacter, Acetatifactor and Kineothrix; and (b) pea fibre (PF); (a) at least one bacterial strain selected from the genera UMGS1375, Lachnospira, Olsenella_E, Murimonas, and Acetatifactor and (b) arabinogalactan (AG); (a) at least one bacterial strain selected from the genera UMGS1375, Acutalibacter, Parabacteroides, Fusicatenibacter, Clostridium_A, Eisenbergiella, Agathobacter, Murimonas and Ruminococcus_A; and (b) resistant dextrin (RD); (a) at least one bacterial strain selected from the genera Blautia_A, Agathobacter, Bifidobacterium, Fusicatenibacter, Acetatifactor, Murimonas; and (b) xylan (XY); (a) at least one bacterial strain selected from the genera UMGS1375, Akkermansia, Ruminococcus_E, GCA- 900066135, Eubacterium_G, Agathobacter, Barnesiella, Mediterraneibacter and CAG-45; and (b) mucin (MU); (a) at least one bacterial strain selected from the genera Anaerostipes, Parabacteroides, Phascolarctobacterium_A, Bacteroides and Phascolarctobacterium; and (b) yeast extract (YE); and / or (a) at least one bacterial strain selected from the genera Agathobacter, Roseburia, Coprococcus, CAG-45, Acetatifactor and Ruminococcus_E; and (b) soluble starch (SS). Preferably, the combination therapy comprises: (a) at least one bacterial strain selected from the group consisting of Acutalibacter timonensis, Acutalibacter sp003612555, Parabacteroides distasonis, Parabacteroides merdae, Fusicatenibacter saccharivorans, Clostridium_A leptum, Eisenbergiella sp900066775, Eisenbergiella massiliensis, Eisenbergiella tayi, UMGS1375 sp900066615, Agathobacter rectalis, Agathobacter faecis, Murimonas intestini, Ruminococcus_A sp000437095, Ruminococcus_A sp003011855; and (b) resistant dextrin (RD); (a) at least one bacterial strain selected from the group consisting of CAG-41 sp900066215, UMGS1441 sp900551755, Lachnospira eligens, Lachnospira rogosae, Lachnospira sp003451515, Lachnospira sp003537285, CAG-274 sp900545305 and UMGS1375 sp900066615 ; and (b) pectin (PE); (a) at least one bacterial strain selected from the group consisting of CAG-41 sp900066215, TF01-11 sp001414325, UMGS1441 sp900551755, Lachnospira rogosae, Lachnospira sp003537285, Ruminiclostridium_E siraeum, Agathobacter faecis, Agathobacter rectalis, Acetatifactor sp900066365, Ruminococcus_D bicirculans, Ruminococcus_D sp900604945, Kineothrix alysoides and (b) pea fibre (PF); (a) at least one bacterial strain selected from the group consisting of UMGS1375 sp900066615, Olsenella_E sp003609875, Murimonas intestini, Acetatifactor sp900066565, Lachnospira eligens and (b) (b) arabinogalactan (AG); (a) at least one bacterial strain selected from the group consisting of UMGS1375 sp900066615, Akkermansia muciniphila, Ruminococcus_E bromii, GCA-900066135 sp900066135, Eubacterium_G ventriosum, Eubacterium_G sp000434315, Agathobacter faecis, Agathobacter rectalis, Barnesiella intestinihominis, Mediterraneibacter faecis, Mediterraneibacter torques, CAG-45 sp900066395 and (b) mucin (MU); (a) at least one bacterial strain selected from the group consisting of Anaerostipes sp90006670, Parabacteroides merdae, Phascolarctobacterium_A succinatutens, Bacteroides faecichinchillae, Bacteroides ovatus, Phascolarctobacterium faecium and (b) yeast extract (YE); (a) at least one bacterial strain selected from the group consisting of Agathobacter rectalis, Agathobacter faecis, Roseburia intestinalis, Roseburia sp001940165, Coprococcus eutactus, CAG-45 sp900066395, Acetatifactor sp900066365, Ruminococcus_E sp003438075 and (b) soluble starch (SS); and / or (a) at least one bacterial strain is selected from the group consisting of Agathobacter rectalis, Blautia_A sp003471165, Blautia_A sp003471165, Bifidobacterium adolescentis, Fusicatenibacter saccharivorans, Acetatifactor sp900066565, Murimonas intestini and (b) xylan (XY). Typically, the at least one bacterial strain is comprised in a bacterial consortium comprising no more than 15 different bacterial strains, preferably between 5 to 15 different bacterial strains, more preferably between 6 and 10 different bacterial strains. The bacterial consortium preferably comprises: - one or several bacterial strain(s) able to convert primary substrates into lactate (A4); - one or several bacterial strain(s) able to convert lactate into butyrate (B3); and / or - one or several bacterial strain(s) able to convert lactate into propionate (B4). Preferably: - the one or several bacterial strain(s) able to convert primary substrates into lactate (A4) transform at least 30%, at least 50%, more preferably at least 60% of the total carbon transformed into the combined metabolites formate (FO), lactate (LT), succinate (SU), acetate (AA), butyrate (BA), propionate (PA) and Ethanol (Et) into lactate when grown for 48 hours in single culture on standard medium - the one or several bacterial strain(s) able to convert lactate into butyrate (B3) degrade at least 20% of lactate in medium and transform at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Et into butyrate when grown for 48 hours in single culture on standard medium supplemented with lactate; and / or - the one or several bacterial strain(s) able to convert lactate into propionate (B4) degrade at least at least 65% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Et into propionate when grown for 48 hours in single culture on standard medium supplemented with lactate. More preferably: - the one or several bacterial strain(s) able to convert primary substrates into lactate (A4) are selected from the genera Agathobacter, Bacteroides, Bariatricus, Bifidobacterium, Collinsella, Enterococcus, Lacticaseibacillus / Lactobacillus, Longicatena, Merdisoma, Peptostreptococcus, Roseburia, Streptococcus and Sutterella; preferably from the genera Agathobacter, Bacteroides, Bariatricus, Collinsella, Enterococcus, Lacticaseibacillus / Lactobacillus, Peptostreptococcus, Streptococcus, and Sutterella; more preferably from the genera Agathobacter, Bacteroides, Bariatricus, Collinsella, Enterococcus, Lacticaseibacillus / Lactobacillus, Streptococcus, and Sutterella; - the one or several bacterial strain(s) able to convert lactate into butyrate (B3) are selected from the genera Anaerobutyricum, Anaerostipes and Eubacterium; preferably from the genera Anaerobutyricum and Anaerostipes; and / or - the one or several bacterial strain(s) able to convert lactate into propionate (B4) are selected from the genera Anaerotignum, Clostridium, Coprococcus_A, Frisingococcus and Veillonella; preferably from the genera Anaerotignum genus, Coprococcus_A, Frisingococcus and Veillonella. Additionally or alternatively, the bacterial consortium comprises: - one or several bacterial strain(s) able to convert primary substrates into formate (A1); - one or several bacterial strain(s) able to convert primary substrates into acetate (A2); - one or several bacterial strain(s) able to convert formate into acetate (B1); and / or - one or several bacterial strain(s) able to convert acetate into butyrate (B2). Preferably: - the one or several bacterial strain(s) able to convert primary substrates into formate (A1) transform at least 20%, at least 25%, more preferably at least 30% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Et into formate when grown for 48 hours in single culture on standard medium; - the one or several bacterial strain(s) able to convert primary substrates into acetate (A2) transform at least 30%, at least 50%, more preferably at least 60% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Et into acetate when grown for 48 hours in single culture on standard medium; - the one or several bacterial strain(s) able to convert formate into acetate (B1) degrade at least 20% of formate in medium and transform at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Et into acetate when grown for 48 hours in single culture on standard medium supplemented with formate; and / or - the one or several bacterial strain(s) able to convert acetate into butyrate (B2) degrade at least 20% of acetate in medium and transform at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Ethanol into butyrate when grown for 48 hours in single culture on standard medium or standard medium supplemented with FO, LT and / or SU. More preferably: - the one or several bacterial strain(s) able to convert primary substrates into formate (A1) are selected from the genera Anaerobutyricum, Bacteroides, Blautia, Collinsella, Coprococcus, Dorea, Erysipelatoclostridium, Escherichia, Eubacterium, Faecalibacterium, Lachnospira, Longicatena, Ruminococcus, and Sellimonas; preferably from the genera Blautia, Coprococcus, Dorea, Erysipelatoclostridium, Faecalibacterium, Lachnospira and Ruminococcus; more preferably from the genera Coprococcus, Dorea, Faecalibacterium and Ruminococcus; - the one or several bacterial strain(s) able to convert primary substrates into acetate (A2) are selected from the genera Acidaminococcus, Acutalibacter, Bifidobacterium, Blautia, Clostridium, Clostridium_E, Clostridium_Q, Collinsella, Copromonas, Desulfovibrio, Dorea, Enterocloster, Escherichia, Eubacterium, Hungatella, Hungatella_A, Oliverbapstia, Peptoniphilus, Peptostreptococcus, Phocaeicola, Rhiziobiaceae genus, Ruminococcus, Sellimonas and Veillonella; preferably from the genera Bifidobacterium, Blautia, Clostridium_Q, Clostridium_E, Desulfovibrio, Dorea, Eubacterium, Oliverpabstia, and Rhiziobiaceae genus; more preferably from the genera Bifidobacterium, Blautia, Clostridium_E, Desulfovibrio, Dorea, Eubacterium, and Rhiziobiaceae genus; - the one or several bacterial strain(s) able to convert formate into acetate (B1) are selected from the genera Blautia and Eubacterium; and / or - the one or several bacterial strain(s) able to convert acetate into butyrate (B2) are selected from the genera Agathobacter, Anaerobutyricum, Anaerostipes, Anaerotignum, Desulfovibrio, Dysosmobacter, Faecalibacterium, Longicatena and Roseburia; preferably from the genera Agathobacter, Anaerobutyricum, Anaerostipes, Desulfovibrio, Faecalibacterium and Roseburia. Additionally or alternatively, the bacterial consortium comprises: - one or several bacterial strain(s) able to convert primary substrates into succinate (A6); and / or - one or several bacterial strain(s) able to convert succinate into propionate (B5). Preferably: - The one or several bacterial strain(s) able to convert primary substrates into succinate (A6) transform at least 30%, at least 50%, more preferably at least 60% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Et into succinate when grown for 48 hours in single culture on standard medium; and / or - The one or several bacterial strain(s) able to convert succinate into propionate (B5) degrade at least 20% of succinate in medium and transform at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Et into propionate when grown for 48 hours in single culture on standard medium supplemented with succinate. More preferably - The one or several bacterial strain(s) able to convert primary substrates into succinate (A6) are selected from the genera Acutalibacter, Bacteroides, Oliverbapstia, Parabacteroides, Phocaeicola and Prevotella; preferably from the genera Acutalibacter nov genus, Bacteroides, Parabacteroides, Phocaeicola and Prevotella; more preferably from the genera Acutalibacter nov genus, Bacteroides, Phocaeicola and Prevotella; and / or - The one or several bacterial strain(s) able to convert succinate into propionate (B5) are selected from the genera Dialister, Flavonifractor, Phascolarctobacterium and Veillonella; preferably from the genera Dialister, Flavonifractor, Phascolarctobacterium and Phascolarctobacterium_A. In some preferred aspects, the at least one bacterial strain is comprised in a bacteria consortium, said bacteria consortium comprising or consisting essentially of Agathobacter rectalis; Anaerostipes caccae or Anaerobutyricum hallii; Ruminococcus bromii; Bifidobacterium adolescentis; Lactobacillus rhamnosus; Blautia hydrogenotrophica; Phascolarctobacterium faecium and a bacterium selected from the group consisting of Bacteroides xylanisolvens, Prevotella copri and Acutalibacter species having at least 95% identity with SEQ ID NO: 6. Preferably, wherein the at least one bacterial strain is comprised in a bacteria consortium, said bacteria consortium comprising or consisting essentially of Agathobacter rectalis; Anaerostipes caccae; Ruminococcus bromii; Bifidobacterium adolescentis; Lactobacillus rhamnosus; Blautia hydrogenotrophica; Phascolarctobacterium faecium and a bacterium selected from the group consisting of Bacteroides xylanisolvens, Prevotella copri and Acutalibacter nov. specie. More preferably, the at least one bacterial strain is comprised in a bacteria consortium, said bacteria consortium comprising or consisting essentially of: - Agathobacter rectalis; Anaerostipes caccae; Ruminococcus bromii; Bifidobacterium adolescentis; Lactobacillus rhamnosus; Blautia hydrogenotrophica; Phascolarctobacterium faecium and Bacteroides xylanisolvens; - Agathobacter rectalis; Anaerostipes Caccae; Ruminococcus bromii; Bifidobacterium adolescentis; Lactobacillus rhamnosus; Blautia hydrogenotrophica; Phascolarctobacterium faecium and Prevotella copri; or - Agathobacter rectalis; Anaerostipes Caccae; Ruminococcus bromii; Bifidobacterium adolescentis; Lactobacillus rhamnosus; Blautia hydrogenotrophica; Phascolarctobacterium faecium and Acutalibacter nov. specie having at least 95% identity with SEQ ID NO 6. In some aspects, the combination therapy comprises or consists of: a) a first pharmaceutical or nutraceutical composition comprising the at least one bacterial strain, optionally comprised in a bacteria consortium, and a second pharmaceutical or nutraceutical composition comprising the at least one dietary fibre and / or carbohydrate source; b) a pharmaceutical or nutraceutical composition comprising (I) the at least one bacterial strain, optionally comprised in a bacteria consortium, and (II) the dietary fibre and / or carbohydrate source. In another aspect, the invention concerns a pharmaceutical or nutraceutical composition comprising a combination therapy disclosed herein. Preferably, the pharmaceutical or nutraceutical composition comprises: (I) a bacterial strain of the genus Lachnospira and (II) pea fiber, pectin and / or arabinogalactan, preferably pectin; (I) a bacterial strain of the genus Ruminococcus_D and (II) pea fiber; (I) a bacterial strain of the genus UMGS1375 (Hominsplanchenecus) and (II) arabinogalactan, resistant dextrin and / or pectin, preferably arabinogalactan and / or pectin; (I) a bacterial strain of the genus Blautia_A and (II) xylan; (I) a bacterial strain of the genus Parabacteroides and (II) resistant dextrin and optionally yeast extract; (I) a bacterial strain of the genus Acutalibacter and (II) resistant dextrin; (I) a bacterial strain of the genus Akkermansia and (II) mucin; (I) a bacterial strain of the genus Agathobacter and (II) pea fiber, resistant dextrin, mucin and / or xylan, preferably pea fiber; (I) a bacterial strain of the genus CAG-41 and (II) pea fiber and / or pectin, resistant dextrin, mucin and / or xylan, preferably pea fiber; (I) a bacterial strain of the genus TF01-11 and (II) pea fiber; (I) a bacterial strain of the genus Acetatifactor and (II) arabinogalactan, pea fiber, soluble starch and / or xylan, preferably pea fiber; (I) a bacterial strain of the genus Fusicatenibacter and (II) xylan; (I) a bacterial strain of the genus Anaerostipes and (II) yeast extract; and / or (I) a bacterial strain of the genus Eisenbergiella and (II) resistant dextrin. In some aspects, the composition further comprises: - propionate, acetate and / or butyrate; and / or - a pharmaceutical excipient or carrier. In another aspect, the invention concerns the combination therapy or the pharmaceutical or nutraceutical composition according of the invention, for use as a medicament, in particular for use in the treatment of intestinal dysbiosis or of a disease or disorder caused by an intestinal dysbiosis. The invention also relates to a method for treating a patient suffering from an intestinal dysbiosis or from a disease or disorder caused by an intestinal dysbiosis, comprising administering a therapeutic amount of the combined therapy or the pharmaceutical or nutraceutical composition of the invention to said patient. Typically, the method further comprises a step of selecting a patient as suitable for treatment with the combined therapy or the pharmaceutical or nutraceutical composition, wherein the patient is selected as suitable if the at least one bacterial strain of the combined therapy is under-represented in the intestinal microbiome of said patient. The invention also refers to the use of the combination therapy or the pharmaceutical or nutraceutical composition of the invention, for the manufacture of a medicament for treating an intestinal dysbiosis or a disease or disorder caused by or related to an intestinal dysbiosis. In some instances, the intestinal dysbiosis is caused by an antibiotic treatment. Additionally or alternatively, the disease or disorder is selected from the group consisting of an inflammatory disease, an auto-immune disease, a cancer, a bacterial infection and a brain disorder, preferably in from the group consisting of infection by vancomycin resistant enterococci (VRE), infection by carbapenem resistant enterococci (CRE), post-infectious diarrhea; Parkinson’s disease (PD), herosclerotic cardiovascular disease (ACVD), coronary artery disease (CAD), hypertension inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohns’s disease (CD); impaired glucose tolerance (IGT), type 1 diabetes (T1D), type 2 diabetes (T2D), rheumatoid arthritis (RA); multiple sclerosis (MS); graft versus host disease (GvHD); gastrointestinal cancer, adenoma, colorectal cancer (CRC), acute myeloid leukemia (AML); gastritis, colitis, gastroenteritis, gingivitis, nosocomial infection and Clostridium difficile infection (CDI). In some aspects, the disease or disorder is acute myeloid leukemia (AML). In some aspects, the disease or disorder is inflammatory bowel disease (IBD). In some aspects, the disease or disorder is a complication following post-hematopoietic stem cell transplantation (HSCT), in particular graft versus host disease (GvHD). In some aspects, the disease or disorder is impaired glucose tolerance (IGT) and / or type 1 diabetes (T1D). In some aspects, the disease or disorder is type 2 diabetes (T2D). In some aspects, the disease or disorder is cancer, in particular adenoma or colorectal cancer (CRC). In some aspects, the disease or disorder is Parkinson’s disease (PD). In some aspects, the disease or disorder is herosclerotic cardiovascular disease (ACVD), coronary artery disease (CAD) and / or hypertension. The invention also concerns a method for establishing a combination therapy for modulating an intestinal microbiome, comprising the steps of: a) Providing a microbiome sample distributed into at least two microbiome test samples, b) Growing a first microbiome test sample of step (a) on a reference substrate; c) Determining an absolute or relative abundance of individual microbe population in the first microbiome test sample at the end of step (b); d) Growing a second microbiome test sample of step (a) on a substrate comprising a nutritionally or therapeutically effective amount of - dietary fibers selected from the group of resistant dextrin RD, pectin PE, pea fiber PF, and arabinogalactan AG; or - a carbohydrate source selected from the group of soluble starch SS, xylan XY, yeast extract YE, mucin MU; e) Determining an absolute or relative abundance of individual microbe population in the second microbiome test sample at the end of step (d); f) Determining microbe population differentially enriched between the first and the second test sample by subtracting the absolute or relative abundance of an individual microbe population of step c) from the absolute or relative abundance of the same individual microbe population of step e); g) Attributing the enriched microbe population of step (f) to the specific substrate comprising resistant dextrin RD, pectin PE, pea fiber PF, arabinogalactan AG; soluble starch SS, xylan XY, yeast extract YE or mucin MU; h) Developing a pharmaceutical or nutritional combination for modulating an intestinal microbiome, said combination comprising (I) at least the enriched microbe population of step f); and (II) the substrate to which the enriched microbe population was attributed to in step f). Finally, the invention concerns a combination therapy comprising or consisting of (i) at least one substrate, said substrate being at least one dietary fibre selected from the group of resistant dextrin (RD), pectin (PE), pea fibre (PF), and arabinogalactan (AG) and / or at least one carbohydrate source selected from the group of soluble starch (SS), xylan (XY), yeast extract (YE) and mucin (MU); and (ii) at least one bacterial strain, wherein the combination therapy has been developed by the method of the invention. DETAILED DESCRIPTION OF THE INVENTION Definitions Unless otherwise defined, all terms of art, notations and other scientific terminology used herein are intended to have the meanings commonly understood by those of skill in the art to which this invention pertains. In order that the present invention may be more readily understood, certain terms are defined hereafter. Additional definitions are set forth throughout the detailed description. As used herein, the terms “microbiome” and “microbiota” are equivalent and refer to the ecological community of commensal, symbiotic, and pathogenic microorganisms that literally share the same given habitat or host. These terms particularly refer to the human gut or intestinal microbiome. The terms “bacterium”, “bacterium strain” and “bacterial strain” can be used interchangeably and denote any bacterium of the taxonomic domain Bacteria. Due to their functions, species of the genera Methanobrevibacter and Candidatus Methanomassiliicoccus (also named herein Methanomassiliicoccus) belonging to the taxonomic domain Archaea shall be herein included in these terms. Preferably, terms “bacterium”, “bacterium strain” and “bacterial strain” refer to the taxonomic domain Bacteria. Definitions of species used herein are defined by sequence identity of their whole genome and / or characteristic sections thereof (as the case may be via reference to a public database). For example, bacteria with a 16S rRNA sequence similarity of at least 95%, 97%, 98%, 99%, 99.5%, 99.6%, 99.7%, 99.8% or 99.9%, preferably 99.9%, are considered as belonging to a same taxon. As the skilled person is aware, nomenclature is constantly subject to changes, due to developing methods of analysis and approaches of the research community. For instance, the genus of Clostridia has been sub-divided into Clostridum_E, Clostridium_Q, etc. Previous and current assignments of genomes to taxons can be retrieved, for example, from https: / / www.ncbi.nlm.nih.gov / Taxonomy / Browser / wwwtax.cgi or from https: / / https: / / gtdb.ecogenomic.org / . Changes in the nomenclature which have been suggested by the research community or a part of the research community and may be of relevance to the present invention include reclassification of Clostridium sporosphaeroides to Clostridium_E sporosphaeroides , Clostridium symbiosum to Clostridium_Q symbiosum, Coprococcus catus to Coprococcus_A catus, Hungatella sp. to Hungatella_A species, Phascolarctobacterium succinatutens to Phascolarctobacterium_A succinatutens, Ruminococcus bromii to Ruminococcus_E bromii. Whenever the traditional term for a genus is used (e.g. Clostridium), it is also meant to cover newly introduced related genera (e.g. Clostridium_E, Clostridium_Q, etc.) It should be noticed that bacterium Clostridium lactatifermentans has been recently renamed Anaerotignum lactatifermentans. Then, as used herein, the terms “Clostridium lactatifermentans” and “Anaerotignum lactatifermentans” have the same meaning and can be used interchangeably. It should also be noticed that bacterium “Eubacterium rectale” has been renamed “Agathobacter rectalis”. Then, as used herein, the terms “Eubacterium rectale” and “Agathobacter rectalis” have the same meaning and can be used interchangeably. It should be noted that bacterium “Eubacterium hallii” has been renamed “Anaerobutyricum hallii”. Then, as used herein, the terms “Eubacterium hallii” and “Anaerobutyricum hallii” have the same meaning and can be used interchangeably. It should be noted that bacterium “Agathobacter faecis” has been renamed “Roseburia faecis”. Then, as used herein, the terms “Agathobacter faecis” and “Roseburia faecis” have the same meaning and can be used interchangeably. It should be noted that bacterium “Lactobacillus rhamnosus” has been renamed “Lacticaseibacillus rhamnosus”. Then, as used herein, the terms “Lactobacillus rhamnosus” and “Lacticaseibacillus rhamnosus” have the same meaning and can be used interchangeably. It should be noted that bacterium “Eubacterium eligens” has been renamed “Lachnospira eligens”. Then, as used herein, the terms “Eubacterium eligens” and “Lachnospira eligens” have the same meaning and can be used interchangeably. The term “consortium”, “microbial consortium” or “bacterial consortium” refers herein to at least three microbial organisms, preferably of five or more bacteria, officiating in the same metabolic or trophic network. Preferably, microbial members of the consortium collaborate, in particular for their subsistence, into the consortium. More preferably, each bacterium of the consortium (i) produces a compound which is utilized by another bacterium of the consortium and / or (ii) utilizes a compound which is produced by another bacterium of the consortium. Preferably it refers to at least three bacterial strains. The term “short chain fatty acids” (SCFA) is also known as volatile fatty acids (VFAs) and specifically denotes fatty acids with two to six carbon atoms. As used herein, the term “intermediate metabolite” denotes a metabolite produced by bacteria that are used as energy source or substrates by other bacteria. Such intermediate metabolites in particular may include degradation products from fibers, proteins or other organic compounds. Preferably, the intermediate metabolites are one or more of formate, lactate and succinate. More generally, the term “intermediate metabolites” may refer to an undesirable metabolite, the presence or amount of which being limited as much as possible in the composition according to the invention. As used herein, the term “end metabolites” denotes the metabolites produced by bacteria that are not or only partially utilized by other bacteria. Preferably, end metabolites include butyrate and acetate and / or propionate, more preferably butyrate. More generally, the term “end metabolites” may refer to a desirable metabolite, the presence or amount of which being enriched in the composition according to the invention. As used here, a "prebiotic" refers to an ingredient that can induce specific changes in both the composition and / or activity of the composition of bacterial strains and / or gastrointestinal microbiome that may confer benefits to the host. Preferably, the prebiotic can be degraded by the consortium of bacterial strains, and may increase its shelf life after administration to a patient. A prebiotic can be an edible food or drink or an ingredient thereof. Prebiotics can include complex carbohydrates, polyphenols and polyunsaturated fatty acids. A prebiotic is usually a non-digestible carbohydrate such as an oligo- or polysaccharide, or a sugar alcohol, which is not degraded or absorbed in the upper digestive tract in the absence of intestinal micro- organisms. As used herein, the term "probiotic" refers to live or inactivated bacteria which, when administered in adequate amounts, have a beneficial effect on the host organism, typically on the host microbiota. Probiotic substances typically contain a sufficiently high number of probiotic micro-organisms to exert a direct or indirect action on the intestinal microbiota or on diseases or disorders caused by or related to intestinal dysbiosis. As used herein, the term "a", "an", "the" and similar terms used in the context of the present invention (especially in the context of the claims) are to be construed to cover both the singular and plural unless otherwise indicated herein or clearly contradicted by the context. As used herein, the terms "including", "containing" and "comprising" are used herein in their open, non- limiting sense. As used herein, the term “consist essentially of” refers to those elements required for a given embodiment. This term indicates the inclusion of any recited characteristics and permits the optional presence of elements that do not materially affect nor change the characteristics or functions of said embodiment. Preferably, in the context of a composition comprising bacteria, it refers to a composition that comprises the recited bacteria, and optionally includes other components such as prebiotics, at the exclusion of other microorganisms such as bacteria. In preferred embodiments, the term “consist essentially of” refers to a composition that comprises the recited bacteria, and optionally includes other components such as prebiotics or particular substrates, at the exclusion of other bacteria. The term “at least one” means “one or more” or “one or several”. For instance, it refers to one, two, three or more. The term “dietary fibre” means carbohydrates including three and more monomers (glucose, galactose, xylose, etc.) that resist digestion and absorption in the small intestine and are completely or partially fermented in the colon by gut bacteria. Dietary fibers relate to indigestible polysaccharides such as oligosaccharides, fructans, pectin, cellulose. The complex dietary fibers discussed herein include resistant dextrin (RD), pectin (PE), pea fiber (PF) and Arabinogalactan (AG); the simpler dietary fibers discussed herein include soluble starch (SS) and xylan (XY). By “Resistant Dextrin” or “RD” is meant a type of soluble fiber that is resistant to digestion in the small intestine, but passes to the large bowel. They are produced by enzymatically breaking down starch into smaller, indigestible molecules. The chemical structure can vary, but they typically consist of linear chains of D-glucose units that are linked together by alpha and beta 1,4-glycosidic bonds, alpha and beta 1,6-glycosidic bonds, alpha and beta 1,2 and 1,3-glycosidic bonds, with various molecular weights. For example, NUTRIOSE FB06 is a soluble resistant dextrin, produced from wheat starch using a patented process, manufactured and marketed by Roquette Frères Company (FR). By “Pectin” or “PE” is meant a complex polysaccharide that is composed of a linear chain of D-galacturonic acid units with varying degrees of methyl esterification. The galacturonic acid units are linked together by alpha-1,4 glycosidic bonds, forming a long chain molecule. Pectin also contains side chains of neutral sugars, such as arabinose, galactose and xylose, which are attached to the galacturonic acid units by alpha-1,2 and alpha-1,3 glycosidic linkages. For example, Pectin from citrus peel can be purchased from Sigma-Aldrich Chemie GmbH (P9135). By “Pea Fiber” or “PF” is meant a complex mixture of polysaccharides (fibers and starch) that forms a structural component of the inner cell walls of peas (i.e., inner cotyledons, not hulls). The fiber part is composed primarily of cellulose, hemicellulose and pectin. Pea fiber (e.g. Inner Pea Fiber I50M) can be purchased from Roquette Frères Company (FR). By “Arabinogalactan” or “AG” is meant a polysaccharide that consists of a main chain of galactose residues with branching arabinose side chains. The galactose residues are linked by beta-1,3-glycosidic bonds, while the arabinose side chains are attached to the galactose residues by alpha-1,6- glycosidic bonds. The arabinose side chains can further branch off to other galactose residues through alpha-1,3- and alpha 1,2 linkages. Arabinogalactan from larch wood can be purchased from Lonza AG (175649). By “Soluble Starch” or “SS” is meant a structure composed of amylose and amylopectin. Amylose is a linear polymer of glucose units that are linked together by alpha-1,4-glycosidic bonds. Amylopectin is likewise of glucose units, albeit branched through alpha-1,6 glycosidic bonds. For example, soluble potato starch may be purchased from Sigma Aldrich Chemie GmbH (S2004). By “Xylan” or “XY” is meant is a type of hemicellulose, a polysaccharide consisting mainly of xylose residues. Specifically, xylan is made of β-1,4-linked xylose (a pentose sugar) residues with side branches of α- arabinofuranose and / or α-glucuronic acids. Xylan from oat spelt may be purchased from Chemie Brunschwig AG (Angene), Basel, Switzerland. The term “glycosilated proteins” includes mucin and yeast extract. By “mucin” or “MU” is meant a glycoprotein. It is composed of repeating units of oligosaccharides and glycosaminoglycans attached to a protein backbone. For example, mucin from porcine stomach can be purchased from Sigma-Aldrich Chemie GmbH (M2378). By yeast extract or “YE” is meant a mixture of amino acids, peptides and vitamins which has been produced by yeast and purified. Yeast extract can be purchased, for example, from Sigma-Aldrich Chemie GmbH (1.11926). Method In a first aspect, the invention is directed to a method for establishing a combination therapy for modulating an intestinal microbiome, comprising the steps of, comprising the steps of: a) Providing a microbiome sample distributed into at least two microbiome test samples, b) Growing a first microbiome test sample of step (a) on a reference substrate; c) Determining an absolute or relative abundance of individual microbe population in the first microbiome test sample at the end of step (b); d) Growing a second microbiome test sample of step (a) on a substrate comprising - complex dietary fibers selected from the group of resistant dextrin RD, pectin PE, pea fiber PF, and arabinogalactan AG; or - a carbohydrate source selected from the group of soluble starch SS, xylan XY, yeast extract YE, mucin MU; e) Determining an absolute or relative abundance of individual microbe population in the second microbiome test sample at the end of step (d); f) Determining microbe population differentially enriched between the first and the second test sample by subtracting the absolute or relative abundance of an individual microbe population of step c) from the absolute or relative abundance of the same individual microbe population of step e); g) Attributing the enriched microbe population of step (f) to a specific substrate selected from the group of resistant dextrin RD, pectin PE, pea fiber PF, and arabinogalactan AG; or selected from the group of soluble starch SS, xylan XY, yeast extract YE, mucin MU; h) Developing a pharmaceutical or nutritional combination for modulating an intestinal microbiome, said combination comprising (I) at least the enriched microbe population of step f); and (II) the substrate to which the enriched microbe population was attributed to in step f). It is particularly preferred that the substrate comprises RD, PE, PF and / or AG. The inventors have found that at the level of complex primary degraders, i.e. degraders of complex energy sources, the mapping of taxon- to-fiber is highly specific. Typically, the substrate comprising a dietary fibers is from the group of resistant dextrin RD, pectin PE, pea fiber PF, and arabinogalactan AG or the carbohydrate source is selected from the group of soluble starch SS, xylan XY, yeast extract YE, mucin, comprises an XY amount of the carbohydrate source of interest. The invention also concerns a method for developing a combination therapy for modulating an intestinal microbiome, said method comprising the steps of: a) Providing an intestinal microbiome sample distributed into at least two microbiome test samples, b) Growing a first intestinal microbiome test sample of step (a) on a reference substrate; c) Determining an absolute or relative abundance of one or more individual microbe populations in the first microbiome test sample at the end of step (b); d) Growing a second microbiome test sample of step (a) on one or more test substrate(s) comprising: - a dietary fibre selected from the group consisting of resistant dextrin (RD), pectin (PE), pea fibre (PF), and arabinogalactan (AG); or - a carbohydrate source selected from the group consisting of soluble starch (SS), xylan (XY), yeast extract (YE), mucin (MU); e) Determining an absolute or relative abundance of one or more individual microbe populations in the second microbiome test sample at the end of step (d); f) Determining one or more individual microbe populations differentially enriched between the first and the second test sample by subtracting the absolute or relative abundance of an individual microbe population of step c) from the absolute or relative abundance of the same individual microbe population of step e); g) Attributing the enriched individual microbe population of step (f) to the one or more dietary fibre(s) or carbohydrate source(s) of step d) on which the individual microbe population was enriched; and h) Developing a combination therapy for modulating an intestinal microbiome, said combination therapy comprising (I) at least one bacterial strain belonging to the same bacterial genera or species than the enriched individual microbe population of step f);; and (II) at least one dietary fibre or carbohydrate source to which the enriched individual microbe population was attributed to in step f). The invention also concerns a method for developing a combination therapy for use in the treatment of an intestinal dysbiosis or a disease or disorder caused by or related to intestinal dysbiosis, said method comprising the steps of: a) Providing an intestinal microbiome sample distributed into at least two microbiome test samples, b) Growing a first intestinal microbiome test sample of step (a) on a reference substrate; c) Determining an absolute or relative abundance of one or more individual microbe populations in the first microbiome test sample at the end of step (b); d) Growing a second microbiome test sample of step (a) on one or more test substrate(s) comprising: - a dietary fibre selected from the group consisting of resistant dextrin (RD), pectin (PE), pea fibre (PF), and arabinogalactan (AG); or - a carbohydrate source selected from the group consisting of soluble starch (SS), xylan (XY), yeast extract (YE), mucin (MU); e) Determining an absolute or relative abundance of one or more individual microbe populations in the second microbiome test sample at the end of step (d); f) Determining one or more individual microbe populations differentially enriched between the first and the second test sample by subtracting the absolute or relative abundance of an individual microbe population of step c) from the absolute or relative abundance of the same individual microbe population of step e); g) Attributing the enriched individual microbe population of step (f) to the one or more dietary fibre(s) or carbohydrate source(s) of step d) on which the individual microbe population was enriched; and h) Developing a combination therapy for modulating an intestinal microbiome, said combination therapy comprising (I) at least one bacterial strain belonging to the same bacterial genera or species than the enriched individual microbe population of step f);; and (II) at least one dietary fibre or carbohydrate source to which the enriched individual microbe population was attributed to in step f). In such methods, the intestinal microbiome sample of step a) is preferably a sample from (I) a healthy subject or population of subjects or (II) a subject or population of subjects suffering from a disease or disorder caused by or related to intestinal dysbiosis. Preferably, the intestinal microbiome sample of step a) is a sample from (I) a healthy subject or population of subjects. Preferably, the healthy individual(s) has / have no history of antibiotic use, intestinal infections, or severe diarrhea during at least three months. Preferably, the intestinal microbiome sample is a fecal or stool sample. The expression “stool”, as used herein, refers to the solid or semisolid fecal remains of food that could not be digested in the intestine. In a particular embodiment, a stool sample is collected from a subject after defecation. The microbiome content of a stool sample from a subject particularly reflects the intestinal microbiome of said subject. In some aspects, the fecal sample is used in serial dilutions in steps of 10 down to 10−11. Typically, the method comprises one or more serial dilution(s) in step (a). Preferably the combination is suitable for patients in which said individual microbe population is under- represented. Preferably, the combination does not include the microbial population enriched from the sample but isolated bacteria identified as to be enriched with a particular substrate. For example, if the method identifies Acutalibacter timonensis, the combination therapy typically comprises an Acutalibacter timonensis bacterial strain from a DSM or ATCC collection. Preferably, the reference substrate is a basal medium, preferably as described in Table A. Table A. Base medium (mM2) and anaerobic dilution solution (ADS) composition Product mM2 ADS Amicase 1 g / L Yeast extract 1.25 g / L Meat extract 0.5 g / L Rumen fluid 300 mL / L Sodium bicarbonate 4 g / L 4 g / L Potassium phosphate dibasic 0.45 g / L 0.59 g / L trihydrate Potassium dihydrogen phosphate 0.45 g / L 0.87 g / L Sodium chloride 0.9 g / L 1.74 g / L Ammonium sulfate 0.9 g / L 1.74 g / L Magnesium sulfate water free 0.09 g / L 0.17 g / L Calcium chloride dihydrate 0.09 g / L 0.17 g / L Resazurin sodium salt 1 g / L 1 g / L L-Cysteine hydrochloride 1 g / L 1 g / L monohydrate Preferably, the basal medium is also used for testing the different dietary fibers and / or carbohydrate sources. Typically, the “test substrate” or “test medium” comprises or consists of a basal substrate supplemented with a single dietary fibers or carbohydrate source. Typically, the method can use 1, 2, 3,4 ,5,6, 7,8 or 9 distinct test substrates (i.e., comprising each a single dietary fibers or carbohydrate source). The reference and / or test medium can further comprise sodium bicarbonate and / or L-cysteine hydrochoride. In some aspects, the dietary fiber or carbohydrate source is selected from Table B. Table B. Supplemented substrates Product AG FiberAid larch wood arabinogalactan PE Pectin from citrus peel XY Xylan from oat spelt SS Starch from potato RD NUTRIOSE® FB06 MU Mucin from porcine stomach (Type II) YE Yeast extract for biotechnology Fermtech® SU Di-sodium succinate LT DL-Lactic acid (90%) The concentration of dietary fiber or carbohydrate source added or to be added in the basal medium is preferably comprised between 1g / L and 10g / L, between 1g / L and 5 g / L, between 2g / L and 10g / L, between 2g / L and 5 g / L, between 2 g / L and 4 g / L or between 2,5 g / L and 3,5 g / L. Preferably, the concentration of dietary fiber or carbohydrate source is about 3g / L. The bacteria of the microbial sample are preferably cultivated / enriched in anaerobic conditions. The method according to the invention particularly comprises a step of determining the absolute or relative abundance of an individual microbe population in the microbiome sample. In one aspect, the method uses the absolute abundance. In an alternative aspect, the method uses the relative abundance. The abundance is the representation of a phylogenic unit in a particular ecosystem. It is usually measured as the number of individuals found per sample. The ratio of abundance of one phylogenic unit to one or multiple other phylogenic unit living in an ecosystem or niche is referred to as relative phylogenic unit abundances. Both indicators are relevant for computing biodiversity. Abundance is in simplest terms usually measured by identifying and counting every individual of every phylogenic unit in a given niche. By “phylogenic unit” it is meant a microbe or a population of microbes of the same genotype, genus, family, species or strain, or of the same molecular origin. A variety of methods are used to measure abundance and are known by the man skilled in the art. Species abundance distribution (SAD) is one of the main uses of this measurement. SAD is a measurement of how common, or rare species are within a niche. This allows to assess how different species are distributed throughout a niche. SAD is one of the most basic measurements in ecology and is used very often, therefore many different methods of measurement and analysis have been developed and are known by the man skilled in the art. Another example of this is Semi-Quantitative Abundance ratings. These are measurement methods which involve estimation based on viewing a specific area of a designated size. The two Semi- Quantitative Abundance ratings used are known as the D.A.F.O.R (D - phylogenic unit observed is "Dominant" in a given niche, A - phylogenic unit observed is "Abundant" in a given niche, F - phylogenic unit observed is "Frequent" in a given niche, O - phylogenic unit observed is "Occasional" in a given niche, R - phylogenic unit observed is "Rare" in a given area) and the A.C.F.O.R. (A – phylogenic unit observed is "Abundant" within the given niche, C – phylogenic unit observed is "Common" within the given niche, F – phylogenic unit observed is "Frequent" within the given niche, O – phylogenic unit observed is "Occasional" within the given niche, R – phylogenic unit observed is "Rare" within the given niche). Abundance estimation also comprises statistical methods for estimating the number of individuals in a population. An “individual microbiome population” is defined as a collection of microbes that share a common trait, such a trait can be of physiological, structural, or genetic nature, for example but not limited to, the same taxonomic unit (e.g. family, class, genus, or species), individual genes or gene clusters, motility, or gram- staining properties. In a particular aspect, by “individual microbe population”, it is meant a population of microorganism, preferably bacteria, that belongs to the same phylogenic unit. The “absolute abundance” is defined as the individual microbe population size (eg. number of cells per volume) in the niche or in the microbiome. The “relative abundance” is a component of biodiversity and refers to how common or rare an individual microbe population is relative to other microbe populations in a defined niche. Relative abundance is preferably the percentage of an individual microbe population relative to the total number of microbes in the niche. Relative phylogenic unit abundances tend to conform to specific patterns that are among the best- known and most-studied patterns in microbial ecology. Different populations in a community exist in relative proportions; this idea is known as relative abundance. Relative phylogenic unit abundance and phylogenic unit richness describe key elements of biodiversity. The relative abundance of an individual microbe population is calculated by measuring a proxy for abundance (e.g., a number of sequencing amplicon reads mapped to a gene, a genome coverage…) and by dividing the measured quantity of each individual microbe population by the sum of the measured quantity across all the microbiome. Absolute and / or relative abundance can be measured using optical density, qPCR, flow cytometry, chamber counting, total bacterial DNA quantification or metagenomic sequencing and grouping of genes. These methods are well known by the man skilled in the art. Preferably, the abundance is measured using optical density, qPCR, microarray technique, amplicon sequencing, single cell sequencing or single cell Matrix Assisted Laser Desorption Ionization - Time of Flight (MALDI-TOF) following flow cytometry or other microfluidic methods, chamber counting, total bacterial DNA quantification or metagenomic sequencing and grouping of genes, proteomic profiling or total RNA sequencing of complex samples. Even more preferably the abundance is measured by amplifying the V3 / V4 region of the hypervariable regions of the 16S rRNA gene and by sequencing amplicons. In one embodiment, the abundance is measured by Amplicon sequence variant (ASV) techniques. ASV refers to individual DNA sequences recovered from a high-throughput marker gene analysis following the removal of spurious sequences generated during PCR amplification and sequencing. Differential enrichment is of particular interest for determining one or more substrate(s) (i.e., comprising a specific dietary fiber or carbohydrate source) that is / are the more suitable for a particular individual bacterial population. Microbe populations which grow equally well under a test condition (i.e., on a particular substrate) and under reference conditions are not specific for a particular substrate. By looking for differentially enriched microbe populations, specific combination of bacteria and suitable substrate can be identified. The term “enrichment” or “enrichment culture” is the use of certain growth conditions to favor the growth of a particular microorganism over others, enriching a sample for the microorganism of interest. Enrichment cultures are used to increase a small number of desired organisms to detectable levels. By “specifically enriched” or “differentially enriched” it is meant that a microorganism, in particular a bacterium, grow differentially depending on the substrate. It can refer to differences in terms of biomass yield and / or growing rate between two or more substrate(s) (i.e., a reference substrate and one or more test substrate comprising the dietary fiber or carbohydrate source). The method can particularly be carried out for two or at least two test substrates. Preferably, the method can be carried out with 2, 3, 4, 5, 6, 7, 8, 9 or test substrates (i.e., in parallel), preferably at the same time. This means that for a specific individual microbial population, one or more subtrate(s) can be identified as suitable for combination with said individual microbial population. Once the partners of the combination therapy have been identified (i.e., the bacterial strain and the one or more adequate substrate(s)), preferably by the method disclosed herein, the combination therapy may be developed by combining purified / isolated bacterial strain(s) (e.g., from National collections or suppliers) and purified substrate(s) (i.e., dietary fiber(s) and / or carbohydrate source(s). Once the partners of the combination therapy have been identified (i.e., the bacterial strain and the one or more adequate substrate(s)), preferably by the method disclosed herein, the combination therapy can typically be as described below. The combination therapy may particularly be in the form of pharmaceutical or nutraceutical combinations / compositions. Combined therapy, pharmaceutical or nutritional combinations The invention relates to a combination of (i) at least one bacterial strain and (ii) at least one dietary fibre and / or carbohydrate source. Preferably, the at least one bacterial strain and the dietary fibre and / or carbohydrate source are combined so as to obtain an synergistic effect, in particular on the intestinal microbiome. By “a synergistic effect” is intended to refer to an effect for: increasing bacterial colonization of the intestine, alleviating intestinal dysbiosis, preventing intestinal dysbiosis, increasing patient survival and / or alleviating symptoms of the disease or disorder caused by or related to intestinal dysbiosis, reducing the frequency of exacerbations intestinal dysbiosis, reducing the frequency of recurrence of intestinal dysbiosis, in particular reducing the number or frequency of flares, which is more than the sum of the effects of each partner alone. Preferably, said combination has been developed by the method disclosed above. As used herein, the terms "combination", "therapeutic combination", "pharmaceutical combination" “combination therapy” or “combined therapy” are used interchangeably and refers to the use of at least two partners, at least one bacterial strain and a substrate (i.e., dietary fiber and / or carbohydrate source). The two partners of the combination therapy can particularly be administered sequentially, separately, simultaneously or substantially simultaneously. As used herein, the term "sequential" or “sequentially” means, unless otherwise specified, characterized by a regular sequence or order, e.g., a sequential dosage regimen could include administration of a particular substrate (i.e., dietary fiber and / or carbohydrate source) before, simultaneously, substantially simultaneously, or after administration of the bacterial strain but both agents will be administered in a regular sequence or order. The term "separate" means, unless otherwise specified, to keep apart one from the other. The term "simultaneously" means, unless otherwise specified, happening or done at the same time, i.e., the partners of the combination therapy of the invention are administered at the same time. The term "substantially simultaneously" means that the agents are administered within minutes of each other (e.g., within 15 minutes of each other) and intends to embrace joint administration as well as consecutive administration, but if the administration is consecutive it is separated in time for only a short period (e.g., the time it would take a medical practitioner to administer two compounds separately). When the partners of the combination are or are to be administered sequentially, the dietary fiber and / or carbohydrate source is preferably administered before the bacterial strain(s). Preferably, the bacterial strain(s) and substrate(s) defined herein, are administered independently at the same time or separately within time intervals that make it possible to demonstrate the synergistic action of the partners in combination. The invention also concerns a combination therapy comprising (i) at least one bacterial strain and (ii) at least one dietary fibre and / or carbohydrate source. Preferably, the combination therapy comprises: (a) at least one bacterial strain selected from the genera Lachnospira, UMGS1375, CAG-41 and UMGS1441, and (b) pectin (PE); (a) at least one bacterial strain selected from the genera Ruminococcus_D, Lachnospira, CAG-41, TF01-11, UMGS1441, Ruminiclostridium_E, Agathobacter, Acetatifactor and Kineothrix; and (b) pea fibre (PF); (a) at least one bacterial strain selected from the genera UMGS1375, Lachnospira, Olsenella_E, Murimonas, and Acetatifactor and (b) arabinogalactan (AG); (a) at least one bacterial strain selected from the genera UMGS1375, Acutalibacter, Parabacteroides, Fusicatenibacter, Clostridium_A, Eisenbergiella, Agathobacter, Murimonas and Ruminococcus_A; and (b) resistant dextrin (RD); (a) at least one bacterial strain selected from the genera Blautia_A, Agathobacter, Bifidobacterium, Fusicatenibacter, Acetatifactor, Murimonas; and (b) xylan (XY); (a) at least one bacterial strain selected from the genera UMGS1375, Akkermansia, Ruminococcus_E, GCA- 900066135, Eubacterium_G, Agathobacter, Barnesiella, Mediterraneibacter and CAG-45; and (b) mucin (MU); (a) at least one bacterial strain selected from the genera Anaerostipes, Parabacteroides, Phascolarctobacterium_A, Bacteroides and Phascolarctobacterium; and (b) yeast extract (YE); and / or (a) at least one bacterial strain selected from the genera Agathobacter, Roseburia, Coprococcus, CAG-45, Acetatifactor and Ruminococcus_E; and (b) soluble starch (SS). Preferably, the combination therapy comprises: (a) at least one bacterial strain selected from the group consisting of Acutalibacter timonensis, Acutalibacter sp003612555, Parabacteroides distasonis, Parabacteroides merdae, Fusicatenibacter saccharivorans, Clostridium_A leptum, Eisenbergiella sp900066775, Eisenbergiella massiliensis, Eisenbergiella tayi, UMGS1375 sp900066615, Agathobacter rectalis, Agathobacter faecis, Murimonas intestini, Ruminococcus_A sp000437095, Ruminococcus_A sp003011855; and (b) resistant dextrin (RD); (a) at least one bacterial strain selected from the group consisting of CAG-41 sp900066215, UMGS1441 sp900551755, Lachnospira eligens, Lachnospira rogosae, Lachnospira sp003451515, Lachnospira sp003537285 and UMGS1375 sp900066615; and (b) pectin (PE); (a) at least one bacterial strain selected from the group consisting of CAG-41 sp900066215, TF01-11 sp001414325, UMGS1441 sp900551755, Lachnospira rogosae, Lachnospira sp003537285, Ruminiclostridium_E siraeum, Agathobacter faecis, Agathobacter rectalis, Acetatifactor sp900066365, Ruminococcus_D bicirculans, Ruminococcus_D sp900604945, Kineothrix alysoides and (b) pea fibre (PF); (a) at least one bacterial strain selected from the group consisting of UMGS1375 sp900066615, Olsenella_E sp003609875, Murimonas intestini, Acetatifactor sp900066565, Lachnospira eligens and (b)arabinogalactan (AG); (a) at least one bacterial strain selected from the group consisting of UMGS1375 sp900066615, Akkermansia muciniphila, Ruminococcus_E bromii, GCA-900066135 sp900066135, Eubacterium_G ventriosum, Eubacterium_G sp000434315, Agathobacter faecis, Agathobacter rectalis, Barnesiella intestinihominis, Mediterraneibacter faecis, Mediterraneibacter torques, CAG-45 sp900066395 and (b) mucin (MU); (a) at least one bacterial strain selected from the group consisting of Anaerostipes sp90006670, Parabacteroides merdae, Phascolarctobacterium_A succinatutens, Bacteroides faecichinchillae, Bacteroides ovatus, Phascolarctobacterium faecium and (b) yeast extract (YE); (a) at least one bacterial strain selected from the group consisting of Agathobacter rectalis, Agathobacter faecis, Roseburia intestinalis, Roseburia sp001940165, Coprococcus eutactus, CAG-45 sp900066395, Acetatifactor sp900066365, Ruminococcus_E sp003438075 and (b) soluble starch (SS); and / or (a) at least one bacterial strain is selected from the group consisting of Agathobacter rectalis, Blautia_A sp003471165, Blautia_A sp003471165, Bifidobacterium adolescentis, Fusicatenibacter saccharivorans, Acetatifactor sp900066565, Murimonas intestini and (b) xylan (XY). Preferably, the combination therapy comprises: (a) at least one bacterial strain selected from the genera Lachnospira, UMGS1375, CAG-41 and UMGS1441, and (b) pectin (PE); (a) at least one bacterial strain selected from the genera Ruminococcus_D, Lachnospira, CAG-41, TF01-11, UMGS1441, Ruminiclostridium_E, Agathobacter, Acetatifactor and Kineothrix; and (b) pea fibre (PF); (a) at least one bacterial strain selected from the genera UMGS1375, Lachnospira, Olsenella_E, Murimonas, and Acetatifactor and (b) arabinogalactan (AG); (a) at least one bacterial strain selected from the genera UMGS1375, Acutalibacter, Parabacteroides, Fusicatenibacter, Clostridium_A, Eisenbergiella, Agathobacter, Murimonas and Ruminococcus_A; and (b) resistant dextrin (RD); (a) at least one bacterial strain selected from the genera Blautia_A, Agathobacter, Bifidobacterium, Fusicatenibacter, Acetatifactor, Murimonas; and (b) xylan (XY); (a) at least one bacterial strain selected from the genera UMGS1375, Akkermansia, Ruminococcus_E, GCA- 900066135, Eubacterium_G, Agathobacter, Barnesiella, Mediterraneibacter and CAG-45; and (b) mucin (MU); (a) at least one bacterial strain selected from the genera Anaerostipes, Parabacteroides, Phascolarctobacterium_A, Bacteroides and Phascolarctobacterium; and (b) yeast extract (YE); and / or (a) at least one bacterial strain selected from the genera Agathobacter, Roseburia, Coprococcus, CAG-45, Acetatifactor and Ruminococcus_E; and (b) soluble starch (SS). Preferably, the combination therapy comprises: (a) at least one bacterial strain selected from the group consisting of Acutalibacter timonensis, Acutalibacter sp003612555, Parabacteroides distasonis, Parabacteroides merdae, Fusicatenibacter saccharivorans, Clostridium_A leptum, Eisenbergiella sp900066775, Eisenbergiella massiliensis, Eisenbergiella tayi, UMGS1375 sp900066615, Agathobacter rectalis, Agathobacter faecis, Murimonas intestini, Ruminococcus_A sp000437095, Ruminococcus_A sp003011855; and (b) resistant dextrin (RD); (a) at least one bacterial strain selected from the group consisting of CAG-41 sp900066215, Lachnospira eligens, Lachnospira rogosae, Lachnospira sp003451515, Lachnospira sp003537285 and UMGS1375 sp900066615; and (b) pectin (PE); (a) at least one bacterial strain selected from the group consisting of CAG-41 sp900066215, TF01-11 sp001414325, Lachnospira rogosae, Lachnospira sp003537285, Ruminiclostridium_E siraeum, Agathobacter faecis, Agathobacter rectalis, Acetatifactor sp900066365, Ruminococcus_D bicirculans, Ruminococcus_D sp900604945, Kineothrix alysoides and (b) pea fibre (PF); (a) at least one bacterial strain selected from the group consisting of UMGS1375 sp900066615, Olsenella_E sp003609875, Murimonas intestini, Acetatifactor sp900066565, Lachnospira eligens and (b)arabinogalactan (AG); (a) at least one bacterial strain selected from the group consisting of UMGS1375 sp900066615, Akkermansia muciniphila, Ruminococcus_E bromii, Eubacterium_G ventriosum, Agathobacter faecis, Agathobacter rectalis, Barnesiella intestinihominis, Mediterraneibacter faecis, Mediterraneibacter torques, CAG-45 sp900066395 and (b) mucin (MU); (a) at least one bacterial strain selected from the group consisting of Anaerostipes sp90006670, Parabacteroides merdae, Phascolarctobacterium_A succinatutens, Bacteroides faecichinchillae, Bacteroides ovatus, Phascolarctobacterium faecium and (b) yeast extract (YE); (a) at least one bacterial strain selected from the group consisting of Agathobacter rectalis, Agathobacter faecis, Roseburia intestinalis, Coprococcus eutactus, CAG-45 sp900066395, Acetatifactor sp900066365, and (b) soluble starch (SS); and / or (a) at least one bacterial strain is selected from the group consisting of Agathobacter rectalis, Blautia_A sp003471165, Blautia_A sp003471165, Bifidobacterium adolescentis, Fusicatenibacter saccharivorans, Acetatifactor sp900066565, Murimonas intestini and (b) xylan (XY). Preferably, the combination therapy comprises: (b) at least one bacterial strain selected from the group consisting of Acutalibacter timonensis, Acutalibacter sp003612555, Parabacteroides distasonis, Parabacteroides merdae, Fusicatenibacter saccharivorans, Clostridium_A leptum, Eisenbergiella sp900066775, Eisenbergiella massiliensis, Eisenbergiella tayi, UMGS1375 sp900066615, Agathobacter rectalis, Agathobacter faecis, Murimonas intestini, Ruminococcus_A sp000437095, Ruminococcus_A sp003011855; and (b) resistant dextrin (RD); (a) at least one bacterial strain selected from the group consisting of CAG-41 sp900066215, Lachnospira eligens, Lachnospira rogosae, Lachnospira sp003451515, Lachnospira sp003537285, and UMGS1375 sp900066615 ; and (b) pectin (PE); (a) at least one bacterial strain selected from the group consisting of CAG-41 sp900066215, TF01-11 sp001414325, Lachnospira rogosae, Lachnospira sp003537285, Ruminiclostridium_E siraeum, Agathobacter faecis, Agathobacter rectalis, Acetatifactor sp900066365, Ruminococcus_D bicirculans, Ruminococcus_D sp900604945, Kineothrix alysoides and (b) pea fibre (PF); (b) at least one bacterial strain selected from the group consisting of UMGS1375 sp900066615, Olsenella_E sp003609875, Murimonas intestini, Acetatifactor sp900066565, Lachnospira eligens and (b) arabinogalactan (AG); (b) at least one bacterial strain selected from the group consisting of UMGS1375 sp900066615, Akkermansia muciniphila, Ruminococcus_E bromii, Eubacterium_G ventriosum, Agathobacter faecis, Agathobacter rectalis, Barnesiella intestinihominis, Mediterraneibacter faecis, Mediterraneibacter torques, CAG-45 sp900066395 and (b) mucin (MU); (b) at least one bacterial strain selected from the group consisting of Anaerostipes sp90006670, Parabacteroides merdae, Phascolarctobacterium_A succinatutens, Bacteroides faecichinchillae, Bacteroides ovatus, Phascolarctobacterium faecium and (b) yeast extract (YE); (b) at least one bacterial strain selected from the group consisting of Agathobacter rectalis, Agathobacter faecis, Roseburia intestinalis, Coprococcus eutactus, CAG-45 sp900066395, Acetatifactor sp900066365, and (b) soluble starch (SS); and / or (b) at least one bacterial strain is selected from the group consisting of Agathobacter rectalis, Blautia_A sp003471165, Blautia_A sp003471165, Bifidobacterium adolescentis, Fusicatenibacter saccharivorans, Acetatifactor sp900066565, Murimonas intestini and (b) xylan (XY). In another aspect, the invention is directed to a pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, said combination comprising (i) a dietary fiber selected from the group of resistant dextrin RD, pectin PE, pea fiber PF, and arabinogalactan AG; or a carbohydrate source selected from the group of soluble starch SS, xylan XY, yeast extract YE, mucin MU AG (ii) at least one bacterial strain identified in a method according as described above. In one embodiment, the pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, comprises a dietary fiber selected from the group of resistant dextrin RD, pectin PE, pea fiber PF, and arabinogalactan AG; or a carbohydrate source selected from the group of soluble starch SS, xylan XY, yeast extract YE, mucin MU AG (ii) and at least one bacterial strain identified in a method as described above. In a specific embodiment, the pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, comprises (a) at least one bacterial strain selected from the genera Acutalibacter, Parabacteroides, Fusicatenibacter, Clostridium_A, Eisenbergiella, UMGS1375, Agathobacter, Murimonas and Ruminococcus_A; (b) resistant dextrin (RD, e.g. Nutriose). In a more specific embodiment, the bacterial strain is selected from Acutalibacter timonensis, Acutalibacter sp003612555, Parabacteroides distasonis, Parabacteroides merdae, Fusicatenibacter saccharivorans, Clostridium_A leptum, Eisenbergiella sp900066775, Eisenbergiella massiliensis, Eisenbergiella tayi, UMGS1375 sp900066615, Agathobacter rectalis, Agathobacter faecis, Murimonas intestini, Ruminococcus_A sp000437095, Ruminococcus_A sp003011855. Then, the bacterial strain of Eisenbergiella may have a 16S rRNA sequence as listed in SEQ ID NO: 1 and SEQ ID NO:2; the bacterial strain of UMGS1375 may have a 16S rRNA sequence as listed in SEQ ID NO: 3. In a specific embodiment, the pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, comprises (a) at least one bacterial strain selected from the genera CAG-41, UMGS1441, Lachnospira, and UMGS1375, and CAG-274; (b) pectin (PE). In a more specific embodiment, the bacterial strain is selected from CAG-41 sp900066215, UMGS1441 sp900551755, Lachnospira eligens, Lachnospira rogosae, Lachnospira sp003451515, Lachnospira sp003537285 and CAG-274 sp900545305 , UMGS1375 sp900066615. Then, the bacterial strain of UMGS1375 sp900066615 may have a 16S rRNA sequence as listed in SEQ ID NO: 3; the bacterial strain of CAG-274 may have a 16S rRNA sequence as listed in SEQ ID NO: 4. In a specific embodiment, the pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, comprises (a) at least one bacterial strain selected from the genera CAG-41, TF01-11, UMGS1441, Lachnospira, Ruminiclostridium_E, Agathobacter, Acetatifactor, Ruminococcus_D, Kineothrix; (b) pea fiber (PF). In a more specific embodiment, the bacterial strain is selected from CAG-41 sp900066215, TF01-11 sp001414325, UMGS1441 sp900551755, Lachnospira rogosae, Lachnospira sp003537285, Ruminiclostridium_E siraeum, Agathobacter faecis, Agathobacter rectalis, Acetatifactor sp900066365, Ruminococcus_D bicirculans, Ruminococcus_D sp900604945, Kineothrix alysoides. In a specific embodiment, the pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, comprises (a) at least one bacterial strain selected from the genera UMGS1375, Olsenella_E, Murimonas, Acetatifactor, Lachnospira; (b) arabinogalactan (AG). In a more specific embodiment, the bacterial strain is selected from UMGS1375 sp900066615, Olsenella_E sp003609875, Murimonas intestini, Acetatifactor sp900066565, Lachnospira eligens. Then, the bacterial strain of UMGS1375 may have a 16S rRNA sequence as listed in SEQ ID NO:3. In one embodiment, the pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, comprises (i) a carbohydrate source selected from the group of soluble starch SS, xylan XY, yeast extract YE, mucin MU (ii) at least one bacterial strain identified in a method as described above. In a specific embodiment, the pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, comprises (a) at least one bacterial strain selected from the genera UMGS1375, Akkermansia, Ruminococcus_E, GCA-900066135, Eubacterium_G, Agathobacter, Barnesiella, Mediterraneibacter, CAG-45; (b) mucin (MU). In a more specific embodiment, the bacterial strain is selected from UMGS1375 sp900066615, Akkermansia muciniphila, Ruminococcus_E bromii, GCA-900066135 sp900066135, Eubacterium_G ventriosum, Eubacterium_G sp000434315, Agathobacter faecis, Agathobacter rectalis, Barensiella intestinihominis, Mediterraneibacter faecis, Mediterraneibacter torques, CAG-45 sp900066395. Then, the bacterial strain of UMGS1375 sp900066615 may have a 16S rRNA sequence as listed in SEQ ID NO:3. In a specific embodiment, the pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, comprises (a) at least one bacterial strain selected from the genera Anaerostipes, Parabacteroides, Phascolarctobacterium_A, Bacteroides, Phascolarctobacterium; (b) yeast extract (YE). In a more specific embodiment, the bacterial strain is selected from Anaerostipes sp90006670, Parabacteroides merdae, Phascolarctobacterium_A succinatutens, Bacteroides faecichinchillae, Bacteroides ovatus, Phascolarctobacterium faecium. In a specific embodiment, the pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, comprises (a) at least one bacterial strain selected from the genera Agathobacter, Roseburia, Coprococcus, CAG-45, Acetatifactor, Ruminococcus_E; (b) soluble starch (SS). In a more specific embodiment, the bacterial strain is selected from Agathobacter rectalis, Agathobacter faecis, Roseburia intestinalis, Roseburia sp001940165, Coprococcus eutactus, CAG-45 sp900066395, Acetatifactor sp900066365, Ruminococcus_E sp003438075. In a specific embodiment, the pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, comprises (a) at least one bacterial strain selected from the genera Agathobacter, Blautia_A, Fusicatenibacter, Bifidobacterium, Fusicatenibacter, Acetatifactor, Murimonas; and (b) xylan (XY). In a more specific embodiment, the bacterial strain is selected from Agathobacter rectalis, Blautia_A sp003471165, Blautia_A sp003471165, Bifidobacterium adolescentis, Fusicatenibacter saccharivorans, Acetatifactor sp900066565, Murimonas intestini. Preferably, the at least one bacterial strain is an isolated or purified bacterial strain. By “isolated” or “purified” bacterial strain is meant a culture of bacteria that has been separated and grown from a single colony or cell, ensuring genetic uniformity. Such isolated bacteria can for example be puchase in adequate companies or retrieved from national repository or collection such as the ones under the Budapest Treaty on the International Recognition of the Deposit of Microorganisms, e.g., the American Type Culture Collection (ATCC), the Deutsche Sammlung von Mikroorganismen und Zellkulturen (DSM or DSMZ). Suitable entries as references for the claimed species in public strain collections can for example be selected in Table C. Table C. References of bacterial strain Acetatifactor sp900066365 DSM 23669 Acutalibacter sp003612555 DSM 26090 Acutalibacter timonensis DSM 102082 Agathobacter faecis DSM 16840Agathobacter rectalisDSM 17629Akkermansia muciniphilaDSM 22959Anaerostipes sp900066705JCM 13470Bacteroides faecichinchillaeDSM 26883Bacteroides ovatusDSM 1896Barnesiella intestinihominisDSM 21032Bifidobacterium adolescentisDSM 20083Blautia_A sp003471165DSM 935Clostridium_A leptum DSM 753 Coprococcus eutactus ATCC 27759 Eisenbergiella massiliensis DSM 101007 Eisenbergiella sp900066775 DSM 26961 Eubacterium_G ventriosum ATCC 27560 Fusicatenibacter saccharivorans DSM 26062 Kineothrix alysoides DSM 100556 Lachnospira eligens ATCC 27750 Lachnospira rogosae ATCC 27753 Lachnospira sp003451515 ATCC 19207Lachnospira sp003537285ATCC 19207Mediterraneibacter faecisJCM 15917Mediterraneibacter torquesATCC 27756Murimonas intestiniDSM 26524Parabacteroides distasonisATCC 8503Parabacteroides merdaeATCC 43184Phascolarctobacterium faeciumDSM 14760Phascolarctobacterium_A succinatutensDSM 22533Roseburia intestinalis DSM 14610 Ruminiclostridium_E siraeum DSM 15702 Ruminococcus_A sp000437095 DSM 107827 Ruminococcus_E bromii ATCC 27255 TF01-11 sp001414325 DSM 105140 UMGS1375 sp900066615 DSM 113194 Ruminococcus_A sp000437095 DSM 107827Ruminococcus_D sp900604945DSM 102216; JCM 34818CAG-41 sp900066215DSM 113452CAG-45 sp900066395DSM 102150Ruminococcus_A sp003011855DSM 106162, JCM 34394Ruminococcus_D bicirculansDSM 102216, JCM 34818Olsenella_E sp003609875 DSM 103345 Preferably, the bacterial strain of Roseburia sp001940165 may have a 16S rRNA sequence as described in SEQ ID NO: 7. Preferably, the bacterial strain of Ruminococcus_E sp003438075 may have a 16S rRNA sequence as described in SEQ ID NO: 8. Preferably, the bacterial strain of Eubacterium_G sp000434315 may have a 16S rRNA sequence as described in SEQ ID NO: 9. Preferably, the bacterial strain of GCA-900066135 sp900066135 may have a 16S rRNA sequence as described in SEQ ID NO: 10. Preferably, the bacterial strain of UMGS1441 sp900551755 may have a 16S rRNA sequence as described in SEQ ID NO: 11. One of skill in the art could identify a suitable isolate by retrieving the sequence from a publicly available database, such as https: / / gtdb.ecogenomic.org / ". Combinations where the bacterial strains is comprised in a consortium In some aspects, the at least one bacterial strain is comprised in a bacterial consortium comprising no more than 15 different bacterial strains , preferably between 5 to 15 different bacterial strains, more preferably between 6 and 10 different bacterial strains. It is particularly preferred that in the combinations as described above, the at least one bacterial strain is comprised in a bacterial consortium of anaerobic bacterial strains, wherein said consortium comprises no more than 15 different bacterial strains, wherein the consortium comprises - one or several bacterial strain(s) able to convert primary substrates into lactate (A4); - one or several bacterial strain(s) able to convert lactate into butyrate (B3); and / or - one or several bacterial strain(s) able to convert lactate into propionate (B4); wherein the primary substrates are selected from the group consisting of sugars, starches, fibers and proteins and any combination thereof. In one embodiment, the said consortium, additionally or alternatively, comprises - one or several bacterial strain(s) able to convert primary substrates into formate (A1); - one or several bacterial strain(s) able to convert primary substrates into acetate (A2); - one or several bacterial strain(s) able to convert formate into acetate (B1); and / or - one or several bacterial strain(s) able to convert acetate into butyrate (B2). In one embodiment, the said consortium, additionally or alternatively, comprises - one or several bacterial strain(s) able to convert primary substrates into succinate (A6); and / or - one or several bacterial strain(s) able to convert succinate into propionate (B5). Such consortia have been described in the art, e.g. in WO2020 / 079036, which is incorporated by reference. They avoid accumulation of intermediate metabolites like lactate, formate, and succinate, and promote production of beneficial end metabolites such as butyrate and propionate. Consortia are more stable and have proven to better engraft in the host. For the purpose of this application the metabolic function of strains is defined as follows: - the strain able to convert primary substrates into formate is able to transform at least 20% of the total carbon transformed into the combined metabolites formate, lactate, succinate; acetate, propionate, butyrate and ethanol into formate when grown at least 48 hours in single culture on standard medium; - the strain able to convert primary substrates into acetate is able to transform at least 30% of the total carbon transformed into the combined metabolites formate, lactate, succinate; acetate, propionate, butyrate and ethanol into acetate when grown at least for at least 48 hours in single culture on standard medium; - the strain able to convert primary substrates into butyrate is able to transform at least 30% of the total carbon transformed into the combined metabolites formate, lactate, succinate; acetate, propionate, butyrate and ethanol into butyrate when grown for at least 48 hours in single culture on standard medium; - the strain able to convert primary substrates into lactate is able to transform at least 30% of the total carbon transformed into the combined metabolites formate, lactate, succinate; acetate, propionate, butyrate and ethanol into lactate when grown for at least 48 hours in single culture on standard medium; - the strain able to convert primary substrates into lactate is able to transform at least 30% of the total carbon transformed into the combined metabolites into propionate when grown for at least 48 hours in single culture on standard medium; - the strain able to convert primary substrates into lactate is able to transform at least 30% of the total carbon transformed into the combined metabolites formate, lactate, succinate; acetate, propionate, butyrate and ethanol into propionate when grown for at least 48 hours in single culture on standard medium; - the strain able to convert primary substrates into lactate is able to transform at least 30% of the total carbon transformed into the combined metabolites formate, lactate, succinate; acetate, propionate, butyrate and ethanol into succinate when grown for at least 48 hours in single culture on standard medium; - the strain able to convert formate into acetate is able to degrade at least 20% of formate and transform at least 20% of the total carbon transformed into the combined metabolites formate, lactate, succinate; acetate, propionate, butyrate and ethanol into acetate when grown for at least 48 hours in single culture on standard medium comprising or supplemented with formate; - the strain able to convert acetate into butyrate is able to degrade at least 20% of acetate and transform at least 20% of the total carbon transformed into the combined metabolites formate, lactate, succinate; acetate, propionate, butyrate and ethanol into butyrate when grown for at least 48 hours in single culture on standard medium comprising or supplemented with acetate; - the strain able to convert lactate into butyrate is able to degrade at least 20% of lactate and transform at least 20% of the total carbon transformed into the combined metabolites formate, lactate, succinate; acetate, propionate, butyrate and ethanol into butyrate when grown for at least 48 hours in single culture on standard medium comprising or supplemented with lactate; - the strain able to convert lactate into propionate is able to degrade at least 20% of lactate and transform at least 20% of the total carbon transformed into the combined metabolites formate, lactate, succinate; acetate, propionate, butyrate and ethanol into propionate when grown for at least 48 hours in single culture on standard medium comprising or supplemented with lactate; and / or - the strain able to convert succinate into propionate is able to degrade at least 20% of formate and transform at least 20% of the total carbon transformed into the combined metabolites formate, lactate, succinate; acetate, propionate, butyrate and ethanol into propionate when grown for at least 48 hours in single culture on standard medium comprising or supplemented with succinate. In a particularly preferred embodiment, the composition comprising the prebiotic strain of the combination may have representatives of the following taxa: - the one or several bacterial strain(s) able to convert primary substrates into formate is / are selected from the genera Anaerobutyricum, Bacteroides, Blautia, Collinsella, Coprococcus, Dorea, Erysipelatoclostridium, Escherichia, Eubacterium, Faecalibacterium, Lachnospira, Longicatena, Ruminococcus, and Sellimonas; preferably from the genera Blautia, Coprococcus, Dorea, Erysipelatoclostridium, Faecalibacterium, Lachnospira and Ruminococcus; more preferably from the genera Dorea, Faecalibacterium and Ruminococcus, even more preferably from the genus Ruminococcus; - the one or several bacterial strain(s) being able to convert primary substrates into acetate is / are selected from the genera Acidaminococcus, Acutalibacter, Bifidobacterium, Blautia, Clostridium, Clostridium_E, Clostridium_Q, Collinsella, Copromonas, Desulfovibrio, Dorea, Enterocloster, Escherichia, Eubacterium, Hungatella, Hungatella_A, Oliverbapstia, Peptoniphilus, Peptostreptococcus, Phocaeicola, Rhiziobiaceae genus, Ruminococcus, Sellimonas and Veillonella; preferably from the genera Bifidobacterium, Blautia, Clostridium_Q, Clostridium_E, Desulfovibrio, Dorea, Eubacterium, Oliverpabstia and Rhiziobiaceae genus; more preferably from the genera Bifidobacterium, Blautia, Desulfovibrio, Dorea, Eubacterium and Rhiziobiaceae genus, even more preferably from the genus Bifidobacterium; - the one or several bacterial strain(s) being able to convert primary substrates into lactate is / are selected from the genera Agathobacter, Bacteroides, Bariatricus, Bifidobacterium, Collinsella, Enterococcus, Lacticaseibacillus / Lactobacillus, Longicatena, Merdisoma, Peptostreptococcus, Roseburia, Streptococcus and Sutterella; preferably from the genera Agathobacter, Bacteroides, Bariatricus, Collinsella, Enterococcus, Lacticaseibacillus / Lactobacillus, Peptostreptococcus, Streptococcus, and Sutterella; more preferably from the genera Agathobacter, Bacteroides, Bariatricus, Collinsella, Enterococcus, Lacticaseibacillus / Lactobacillus, Streptococcus and Sutterella, even more preferably from the genus Lactobacillus; - the one or several bacterial strain(s) being able to convert primary substrates into succinate is / are selected from the genera Acutalibacter novel genus, Bacteroides, Oliverbapstia, Parabacteroides, Phocaeicola and Prevotella; preferably from the genera Acutalibacter nov genus, Bacteroides, Parabacteroides, Phocaeicola and Prevotella; more preferably from the genera Acutalibacter nov genus, Bacteroides, Phocaeicola and Prevotella, even more preferably from the genera Bacteroides and Prevotella; - the one or several bacterial strain(s) being able to convert formate into acetate is / are selected from the genera Blautia and Eubacterium; preferably from the genus Blautia; - the one or several bacterial strain(s) being able to convert acetate into butyrate is / are selected from the genera Agathobacter, Anaerobutyricum, Anaerostipes, Anaerotignum, Desulfovibrio, Dysosmobacter, Faecalibacterium, Longicatena and Roseburia and any combination thereof; preferably from the genera Agathobacter, Anaerobutyricum, Anaerostipes, Desulfovibrio, Faecalibacterium and Roseburia; - the one or several bacterial strain(s) being able to convert lactate into butyrate is / are selected from the genera Anaerobutyricum, Anaerostipes and Eubacterium and any combination thereof; preferably from the genera Anaerobutyricum and Anaerostipes; - the one or several bacterial strain(s) being able to convert lactate into propionate is / are selected from the genera Anaerotignum, Clostridium (Clostridium_E), Coprococcus_A, Frisingococcus and Veillonella and any combination thereof; preferably from the genera Anaerotignum genus, Coprococcus_A, Frisingococcus and Veillonella; and / or - the one or several bacterial strain(s) being able to convert succinate into propionate is / are selected from the genera Dialister, Flavonifractor, Phascolarctobacterium Phascolarctobacterium_A and Veillonella, preferably from Dialister, Flavonifractor, and Phascolarctobacterium and Phascolarctobacterium_A, more preferably from the genus Phascolarctobacterium. In a particularly preferred embodiment, the composition comprising the prebiotic strain of the combination may have representatives of the following taxa: - the one or several bacterial strain(s) able to convert primary substrates into formate is / are selected from the species Bacteroides clarus, Blautia hydrogenotrophica, Collinsella aerofaciens, Coprococcus eutactus, Dorea formicigenerans, Dorea longicatena, Erysipelatoclostridium ramosum, Eubacterium ramulus, Faecalibacterium prausnitzii, Lachnospira (Eubacterium) eligens , Longicatena sp., Ruminococcus bromii and Sellimonas intestinalis; preferably from the species Blautia hydrogenotrophica, Coprococcus eutactus, Dorea formicigenerans, Dorea longicatena, Erysipelatoclostridium ramosum, Faecalibacterium prausnitzii, Lachnospira eligens and Ruminococcus bromii; more preferably from the species Dorea formicigenerans, Dorea longicatena, Faecalibacterium prausnitzii and Ruminococcus bromii; most preferably is from the species Ruminococcus bromii; - the one or several bacterial strain(s) being able to convert primary substrates into acetate is / are selected from the species Acidaminococcus intestini, Acutalibacter nov. genus having a 16SRNA sequence such as set forth in SEQ ID NO: 5 and any variant thereof having at least 97%, 98% or 99% sequence identity thereto, Bifidobacterium adolescentis, Bifidobacterium catenulatum, Bifidobacterium longum, Bifidobacterium pseudocatenulatum, Bifidobacterium ruminantium, Blautia hydrogenotrophica, Clostridium perfringens, Clostridium_E sporosphaeroides, Clostridium_Q symbiosum, Collinsella aerofaciens, Copromonas sp, Desulfovibrio piger, Dorea formicigenerans, Dorea longicatena, Dorea scindens, Dorea sp. 900066555, Enterocloster sp., Escherichia coli, Eubacterium callanderi, Eubacterium limosum, Hungatella effluvii, Hungatella_A sp., Oliverpabstia sp., Peptoniphilus vaginalis, Peptostreptococcus anaerobius, Phocaeicola plebeius , Rhizobiaceae nov. genus, Ruminoccocus bromii, Sellimonas intestinalis and Veillonella ratti; preferably from the species Bifidobacterium adolescentis, Bifidobacterium catenulatum, Bifidobacterium longum, Bifidobacterium pseudocatenulatum, Bifidobacterium ruminantium, Blautia hydrogenotrophica, Clostridium_Q symbiosum, Clostridium_E sporosphaeroides, Desulfovibrio piger, Dorea formicigenerans, Dorea longicatena, Dorea scindens, Dorea sp.900066555, Eubacterium callanderi, Eubacterium limosum, Oliverpabstia sp. and Rhizobiaceae nov. genus; more preferably from the species Bifidobacterium adolescentis, Bifidobacterium catenulatum, Bifidobacterium longum, Bifidobacterium pseudocatenulatum, Bifidobacterium ruminantium, Blautia hydrogenotrophica, Desulfovibrio piger, Dorea longicatena, Eubacterium callanderi, Eubacterium limosum and Rhizobiaceae nov. genus; most preferably is from the species Bifidobacterium adolescentis, - the one or several bacterial strain(s) being able to convert primary substrates into lactate is / are selected from the species Agathobacter / Roseburia faecis, Bacteroides clarus, Bacteroides faecis, Bacteroides uniformis, Bariatricus comes, Bifidobacterium adolescentis, Collinsella aerofaciens, Enterococcus faecalis, Enterococcus faecium, Enterococcus gallinarum, Lacticaseibacillus rhamnosus / Lactobacillus rhamnosus, Longicatena sp., Merdisoma Aerosacheriphilus, Peptostreptococcus stomatis, Roseburia hominis, Streptococcus anginosus and Sutterella wadsworthensis; preferably from the species Agathobacter faecis (also named Roseburia faecis), Bacteroides clarus, Bacteroides uniformis, Bariatricus comes, Collinsella aerofaciens, Enterococcus faecalis, Enterococcus faecium, Enterococcus gallinarum, Lacticaseibacillus rhamnosus (also named Lactobacillus rhamnosus), Peptostreptococcus stomatis, Streptococcus anginosus and Sutterella wadsworthensis; more preferably from the species Bacteroides uniformis, Bariatricus comes, Collinsella aerofaciens, Enterococcus faecalis, Enterococcus faecium, Enterococcus gallinarum, Lacticaseibacillus rhamnosus (also named Lactobacillus rhamnosus), Streptococcus anginosus and Sutterella wadsworthensis; most preferably is from the species Lactobacillus rhamnosus; - the one or several bacterial strain(s) being able to convert primary substrates into succinate is / are selected from the species Acutalibacter nov. genus having a DNA genome sequence as set forth in SEQ ID NO:6 or a variant of at least 90%, 95%, or 99% identity thereto and / or having a 16S rRNA sequence as set forth in SEQ ID NO: 5 or a variant having at least 95%, preferably at least 97%, more preferably 99%, 99.5%, 99.7% or 99.9% sequence identity thereto), Bacteroides faecis, Bacteroides fragilis, Bacteroides thetaiotaomicron, Bacteroides xylanisolvens, Oliverpabstia sp., Bacteroides faecis, Parabacteroides distasonis, Phocaeicola dorei, Phocaeicola plebeius, Phocaeicola vulgatus and Prevotella copri; preferably from Acutalibacter nov genus, Bacteroides faecis, Bacteroides fragilis, Bacteroides thetaiotaomicron, Bacteroides xylanisolvens, Parabacteroides distasonis, Phocaeicola dorei, Phocaeicola plebeius, Phocaeicola vulgatus and Prevotella copri; more preferably from the species Acutalibacter nov. genus, Bacteroides faecis, Bacteroides fragilis, Bacteroides thetaiotaomicron, Bacteroides xylanisolvens, Phocaeicola plebeius, Phocaeicola vulgatus and Prevotella copri; most preferably from the species Acutalibacter nov. genus (in particular having a DNA genome sequence as set forth in SEQ ID NO: 5 or a variant of at least 90%, 95%, or 99% identity thereto and / or having a full genome sequence as set forth in SEQ ID NO: 6 or a variant having at least 95%, preferably at least 97%, more preferably 99%, 99.5%, 99.7% or 99.9% sequence identity thereto), Prevotella copri and Bacteroides xylanisolvens; - the one or several bacterial strain(s) being able to convert formate into acetate is / are selected from the species Blautia hydrogenotrophica, Eubacterium callanderi and Eubacterium limosum, preferably from the species Blautia hydrogenotrophica; - the one or several bacterial strain(s) being able to convert acetate into butyrate is / are selected from the species Agathobacter rectalis / Eubacterium rectale (e.g., DSM 17629), Agathobacter / Roseburia faecis (e.g., DSM 16840), Anaerobutyricum / Eubacterium hallii (e.g., ATCC 27751, DSM 3353, JCM 31263), Anaerostipes caccae (e.g., DSM 14662, JCM 13470), Anaerostipes hadrus (e.g., ATCC 29173, DSM 3319), Anaerotignum sp., Desulfovibrio piger (e.g., ATCC 29098, DSM 749), Dysosmobacter sp., Faecalibacterium prausnitzii (e.g., ATCC 27768, ATCC 27766,DSM 17677, JCM 31915), Longicatena sp., Roseburia hominis (e.g., DSM 16839) and Roseburia intestinalis (e.g., DSM 14610, JCM 31262) and any combination thereof; preferably Agathobacter rectalis, Anaerobutyricum hallii, Anaerostipes caccae, Anaerostipes hadrus, Desulfovibirio piger, Faecalibacterium prausnitzii, Roseburia hominis and Roseburia intestinalis; more preferably Anaerobutyricum hallii, Anaerostipes caccae and Agathobacter rectalis. - the one or several bacterial strain(s) being able to convert lactate into butyrate is / are selected from the species Anaerobutyricum / Eubacterium hallii (e.g., ATCC 27751, DSM 3353, JCM 31263), Anaerostipes caccae (e.g., DSM 14662, JCM 13470), Eubacterium callanderi (e.g., ATCC 49165, DSM 3662, JCM 10284) and Eubacterium limosum (e.g., ATCC 8486, DSM 20543, JCM 6421, JCM 9978) and any combination thereof; preferably from Anaerobutyricum hallii and Anaerostipes caccae; - the one or several bacterial strain(s) being able to convert lactate into propionate is / are selected from the species., Clostridium_E sporosphaeroides (e.g., ATCC 25781, DSM 1294), Coprococcus_A catus (e.g., ATCC 27761), Veillonella atypica (e.g., ATCC 17744, DSM 20739), Veillonella parvula subsp. parvula (e.g., DSM 2008), Veillonella ratti (e.g., ATCC 17746, DSM 20736, JCM 6512) and any combination thereof, preferably from Anaerotignum nov sp., Coprococcus_A catus, Frisingococcus sp., Veillonella atypica and Veillonella parvula subsp. parvula - wherein the one or several bacterial strain(s) being able to convert succinate into propionate is / are selected from the species Dialister hominis, Dialister invisus, Flavonifractor plautii, Phascolarctobacterium faecium, Phascolarctobacterium_A succinatutens, Veillonella parvula subsp. parvula and Veillonella ratti, preferably from Dialister hominis, Dialister invisus, Flavonifractor plautii, Phascolarctobacterium faecium and Phascolarctobacterium_A succinatutens; more preferably from the species Phascolarctobacterium faecium. In a particularly preferred embodiment, the bacteria consortium essentially consists of the strain of the combination (i.e. differentially enriched on the dietary fiber of interest) and - one or several bacterial strain(s) able to convert primary substrates into formate (A1); - one or several bacterial strain(s) able to convert primary substrates into acetate (A2); - one or several bacterial strain(s) able to convert primary substrates into lactate (A3); - one or several bacterial strain(s) able to convert primary substrates into succinate (A6); - one or several bacterial strain(s) able to convert formate into acetate (B1); - one or several bacterial strain(s) able to convert acetate into butyrate (B2); - one or several bacterial strain(s) able to convert lactate into butyrate (B3); - one or several bacterial strain(s) able to convert lactate into propionate (B4); and / or - one or several bacterial strain(s) able to convert succinate into propionate (B5). If the bacterial strain of the combination (i.e. differentially enriched on the dietary fiber of interest) performs at the same time one of the above listed functions (A1), (A2), (A3), (A6), (B1), (B2),(B3), (B4) and / or (B5), such function can be omitted in the consortium. For example, if the combination comprises wherein the primary substrates are selected from the group consisting of sugars, starches, fibers and proteins and any combination thereof. In one embodiment, the said consortium, additionally or alternatively, comprises resistant dextrin (RD) and a bacterial strain of Acutalibacter genus (16SRNA as described in SEQ ID NO:5 or genomic DNA as described in SEQ ID NO: 6), the consortium which includes the Acutalibacter strain does not need to comprise another strain having (A6) function. Also, functions (B3) and (B4) are redundant. It is preferred that the composition comprises either a strain performing (B3) function or a strain performing (B4) function. It is particularly preferred that the composition comprises only a strain performing (B3) function. Detailed description of the Consortia The inventors have developed specific consortia of bacterial species which both reflect the intestinal microbiome complexity and increase desirable end metabolites production, especially butyrate. The bacterial strains of the consortia disclosed herein have been selected to enable metabolic cross-feeding interactions or collaboration between each other. Preferably, bacteria of the consortia disclosed herein are bacteria of the intestinal or gut microbiota, in particular of human gut or intestinal microbiota. Preferably, such bacteria are not pathogenic bacteria. This means that bacteria according to the invention are known as not able to trigger any disease or disorder in a subject. Preferably, bacteria used in the present invention are bacteria strains of class I. Preferably, the bacteria of the consortia used in the present invention are facultatively or strictly anaerobic. Preferably, the bacteria of the consortium are isolated or purified bacteria, such as isolated or purified from a human intestinal microbiome. In microbiology, the term “isolation” or “purification” refers to the separation of a bacterial strain from a natural, mixed population of living microbes, such as the gut microbiota, or extracted from a sample of such gut microbiota, such as a fecal or stool sample. Preferably, the bacteria of the consortia disclosed herein are live bacteria. The terms “viable bacterium” and “live bacterium” can be used interchangeably and denote a bacterium which has the capacity to grow under suitable conditions. Bacterial viability can be measured using biochemical assays. Preferably, these terms relate to a bacterium strain (i) having a viability of over 50% (e.g., in compositions such as pharmaceutical compositions), typically over 60% and preferably over 90%, in particular as determined by flow cytometry. In order to create a consortium reflecting the gut microbiota complexity, the inventors have identified key functions / pathways that are performed by bacteria of an intestinal microbiome. When bacteria are assembled into a particular consortium according to the invention, each of the bacterial strain of the consortium is able to perform a pathway selected from the group consisting of pathways A1, A2, A3, A4, A5, A6, B1, B2, B3, B5, C1 and C2 and any combination thereof. Optionally, a bacterial strain of the consortium may be able to perform pathway B4. Preferably, the consortium does not comprise any bacteria which is able to perform pathway B4. These pathways are defined below. As used herein, pathway (A1) corresponds to the conversion of primary substrates and production of formate. Then, a bacterial strain able to convert primary substrates such as sugars, starches, fibers and / or proteins into formate performs pathway A1. In particular, bacteria performing pathway (A1) are able to transform at least 20%, at least 25%, more preferably at least 30% of the total carbon transformed into the combined metabolites, i.e. formate (FO), lactate (LT), succinate (SU), acetate (AA), propionate (PA), butyrate (BA) and Ethanol (Et), into formate, especially when grown for at least 48 hours in single culture on standard medium. In other words, after the experiment, at least 20%, at least 25% or at least 30%, preferably at least 30%, of the total carbon in the combined metabolites (FO+LT+SU+AA+PA+BA+Et) is present as formate. By “single culture” it is meant a method of growing isolated bacteria from a single specie or genus on a nutrient standard medium under controlled condition. By “standard medium” is meant a media that will support the growth of a wide variety of bacteria. Standard medium usually comprises a carbon source, a source of potassium and / or phosphorus; a source of nitrogen and / or sulfur; and a source of magnesium. Examples of suitable standard medium are YCFA and M2GSC which are well known to those of skill in the art. YCFA can be prepared as described in Duncan et al., Roseburia intestinalis sp. nov., a novel saccharolytic, butyrate-producing bacterium from human faeces. Int J Syst Evol Microbiol. 2002;52:1615–1620. doi:10.1099 / 00207713-52-5-1615. It is mainly composed of casitone, yeast extract, buffer (NaHCO3), reducing agent (cysteine, resazurin), mineral sources (K2HPO4, KH2PO4, NaCl, MgSO4, CaCl2), vitamins (biotin, cobalamin, aminobenzoic acid, folic acid, pyridoxamine). M2GSC can be prepared as described in Miyazaki et al., Degradation and utilization of xylans by the rumen anaerobe Prevotella bryantii (formerly P. ruminicola subsp. brevis) B14. Anaerobe. 1997;3:373–381. doi:10.1006 / anae.1997.0125. It is mainly composed of casitone, yeast extract, buffer (NaHCO3), glucose, cellbiose, soluble starch, rumen fluid, reducing agent (cysteine, resazurin), mineral sources (K2HPO4, KH2PO4, NaCl, MgSO4, CaCl2). As used herein, pathway (A2) corresponds to the conversion of primary substrates and production of acetate. Then, a bacterial strain able to convert primary substrates such as sugars, starches, fibers and / or proteins into acetate performs pathway A2. In particular, bacteria performing pathway (A2) are able to transform at least 30%, at least 50%, more preferably at least 60% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Ethanol into acetate, especially when grown for at least 48 hours in single culture on standard medium. In other words, after the experiment, at least 30%, at least 50% or at least 60%, preferably 60%, of the total carbon in the combined metabolites (FO+LT+SU+AA+PA+BA+Et) is present as acetate. As used herein, pathway (A3) corresponds to the conversion of primary substrates and production of butyrate. In particular, bacteria performing pathway (A3) are able to transform at least 30%, at least 50%, more preferably at least 60% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Ethanol into butyrate, especially when grown for at least 48 hours in single culture on standard medium. In other words, after the experiment, at least 30%, preferably at least 50%, more preferably 60%, of the total carbon in the combined metabolites (FO+LT+SU+AA+PA+BA+Et) is present as butyrate. As used herein, pathway (A4) corresponds to the conversion of primary substrates and production of lactate. In particular, bacteria performing pathway (A4) are able to transform at least 30%, at least 50%, more preferably at least 60% of the total carbon transformed into FO, LT, SU, AA, PA, BA and Ethanol into lactate, especially when grown for at least 48 hours in single culture on standard medium. In other words, after the experiment, at least 30%, preferably at least 50%, more preferably at least 60% of the total carbon in the combined metabolites (FO+LT+SU+AA+PA+BA+Et) is present as lactate. As used herein, pathway (A5) corresponds to the conversion of primary substrates and production of propionate. In particular, bacteria performing pathway (A5) are able to transform at least 30%, at least 50%, more preferably at least 60% of the total carbon transformed into FO, LT, SU, AA, PA, BA and Ethanol into acetate, especially when grown for at least 48 hours in single culture on standard medium. In other words, after the experiment, at least 30%, preferably at least 50%, more preferably at least 60% of the total carbon in the combined metabolites (FO+LT+SU+AA+PA+BA+Et) is present as acetate. As used herein, pathway (A6) corresponds to the conversion of primary substrates and production of succinate. In particular, bacteria performing pathway (A6) are able to transform at least 30%, at least 50%, more preferably at least 60% of the total carbon transformed into FO, LT, SU, AA, PA, BA and Ethanol into succinate, especially when grown for at least 48 hours in single culture on standard medium. In other words, after the experiment, at least 30%, preferably at least 50%, more preferably at least 60% of the total carbon in the combined metabolites (FO+LT+SU+AA+PA+BA+Et) is present as succinate. As used herein, pathway (B1) corresponds to the conversion of formate and production of acetate. In particular, bacteria performing pathway (B1) are able to degrade at least 20% of formate in medium and transform at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Ethanol into acetate, especially when grown for at least 48 hours in single culture on standard medium comprising or supplemented with formate. In other words, after the experiment, at least 30%, preferably at least 50%, more preferably at least 65% of the total carbon in the combined positively accumulated metabolites (FO+LT+SU+AA+PA+BA+Et | Δmetabolite> 0) is present as acetate. As used herein, pathway (B2) corresponds to the conversion of acetate and production of butyrate. In particular, bacteria performing pathway (B2) degrade at least 20% of acetate in medium and transform at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Ethanol into butyrate, especially when grown for at least 48 hours in single culture on standard medium or standard medium comprising or supplemented with FO, LT and / or SU. In other words, after the experiment, at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon in the combined positively accumulated metabolites (FO+LT+SU+AA+PA+BA+Et | Δmetabolite> 0) is present as butyrate. As used herein, pathway (B3) corresponds to the conversion of lactate and production of butyrate. In particular, bacteria performing pathway (B3) degrade at least 20% of lactate in medium and transform at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Ethanol into butyrate, especially when grown for at least 48 hours in single culture on standard medium comprising or supplemented with lactate. In other words, after the experiment, at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon in the combined positively accumulated metabolites (FO+LT+SU+AA+PA+BA+Et | Δmetabolite> 0) is present as butyrate.As used herein, pathway (B4) corresponds to the conversion of lactate and production of propionate. In particular, bacteria performing pathway (B4) degrade at least 20% of lactate in medium and transform at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Ethanol into propionate, especially when grown for at least 48 hours in single culture on standard medium comprising or supplemented with lactate. In other words, after the experiment, at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon in the combined positively accumulated metabolites (FO+LT+SU+AA+PA+BA+Et | Δmetabolite> 0) is present as propionate. As used herein, pathway (B5) corresponds to the conversion of succinate and production of propionate. In particular, bacteria performing pathway (B5) degrade at least 20% of succinate in medium and transform at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Ethanol into propionate, especially when grown for at least 48 hours in single culture on standard medium comprising or supplemented with succinate. In other words, after the experiment, at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon in the combined positively accumulated metabolites (FO+LT+SU+AA+PA+BA+Et | Δmetabolite> 0) is present as propionate. As used herein, pathway (C1) corresponds to the conversion of primary substrates to lactate while reducing oxygen. As used herein, pathway (C2) corresponds to the conversion of H2, CO2 and formate to acetate. Literature data on hydrogen utilization or oxygen tolerability were used to assign C-reactions to the strains, whereby oxygen reduction was assigned to strains reported to grow under aerobic or microaerophilic conditions and hydrogen consumption to acetogenic or methanogenic gut bacteria. Bacterial strains being able to maintain concentrations in the culture medium of O2 below a concentration inhibiting proliferation of at least one bacterial strain of the consortium can be identified as described in literature (O2 concentration < 2mg / L in the liquid phase and / or RedOx potential < -250mV; see Ricciardi et al., Rapid detection assay for oxygen consumption in the Lactobacillus casei group, Ann Microbiol 64, 1861–1864 (2014). Bacterial strains being able to maintain concentrations in the culture medium of H2 below a concentration inhibiting proliferation of at least one bacterial strain of the consortium can be identified as described in literature, by analyzing the H2 amount in the headspace of a Hungate tube (preferably below 4%; see Leclerc et al., H2 / CO2 metabolism in acetogenic bacteria, isolated from the human colon, Anaerobe, 3(5), 307-315 (1997); Pham et al., Lactate-utilizing community is associated with gut microbiota dysbiosis in colicky infants. Sci Rep.; 7(1):11176 (2017)). Then, bacteria are particularly defined herein by their capacities or abilities to perform particular pathways of an intestinal microbiome. Such abilities are for example capacity to degrade or convert a particular substrate, for example such as starch, and to produce a particular product or metabolite, for example such as butyrate. Generally, one bacterium is able to degrade or convert a substrate (e.g., starch) and to produce a product (e.g., butyrate). Accordingly, bacteria that are able to degrade or convert the same substrate(s) (e.g., starch) and to produce the same metabolite(s) (e.g., butyrate) performe the same pathways. Such capacities of a bacterium are well known in the art. Experiments are known in the art to test whether a bacterial strain is able to perform a metabolic pathway. For example, the degradation of sugars, starches or fibers can be tested simply by providing such substrate to bacteria while observing or monitoring their growth. For example, bacteria can be characterized for growth and metabolite production on M2GSC Medium (e.g., ATCC Medium 2857) and modifications thereof whereby the carbon sources glucose, cellobiose and starch are replaced by specific substrates including intermediate metabolites and / or fibers, preferably such as found in the human intestine. The concentrations of the produced metabolites can for example be quantified by any analytic method available for the person skilled in the art such as refractive index detection high pressure liquid chromatography (HPLC-RI; for example, as provided by Thermo Scientific Accela™). Additional examples of such experiments are provided below for each of the different groups of pathways. In such examples, the concentration of metabolites is preferably determined by centrifuging a liquid culture sample before / after the at least 48 hours growth period, filtering the supernatant, and subjecting filtrate to refractive index detection high pressure liquid chromatography (HPLC-RI). In particular, to test whether a bacterial strain is able to perform pathways (A1)-(A6), the experiment can be as follows: the bacterial strain, when grown in single culture, strictly anaerobically, in Hungate tubes for at least 48 hours on YCFA medium (Yeast extract, casitone, fatty acids) and / or M2GSC medium (Glucose, soluble starch, cellbiose medium) at pH 6.5-7 and 37°C, is able to transform a defined minimal share of the total carbon converted into the combined metabolites FO, LT, SU, AA, PA, BA and Et into the metabolite of interest. For example, the condition for a bacterial strain to qualify as a formate producer (performing pathway A1) is: (^^^^ ^^^^ ^^^^ [ ^^^^ ^^^^])∗1^^^^ ^^^^ ^^^^ [ ^^^^ ^^^^]∗1 + ^^^^ ^^^^ ^^^^[ ^^^^ ^^^^]∗2 + ^^^^ ^^^^ ^^^^ [ ^^^^ ^^^^]∗4 +> 0.2 For instance, the minimal share for formate (pathway A1) is 0.2, preferably 0.25, more preferably 0.3. The minimal share for acetate (A2), butyrate (A3), lactate (A4), propionate (A5) and succinate (A6) are 0.3, preferably 0.5, more preferably 0.6. To test if a bacterial strain is able to perform pathways (B1),(B3)-(B5) the experiment can be as follows: the bacterial strain, when grown in single culture, strictly anaerobically, in Hungate tubes for at least 48 hours on modified M2GSC or YCFA medium at pH 6.5-7 and 37°C, degrade at least 20% of the intermediate metabolite of interest (FO, LT, SU), and transform at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon converted into the combined metabolites FO, LT, SU, AA, PA, BA and Et (i.e., those of FO, LT, SU, AA, PA, BA and Et which are positively accumulated) into the respective end metabolite of interest (AA, BA, PA). The modified media M2FO, M2LT and M2SU particularly contain 30 mM of formate (FO), 30mM of DL-lactate (LT), or 30 mM of sodium succinate (SU), respectively. For example, the conditions for a bacterial strain to qualify as a lactate to butyrate converter (performing pathway B3), are: 1)^^^^ ^^^^ ^^^^ [ ^^^^ ^^^^]^^^^ ^^^^ ^^^^ ^^^^ ^^^^ ^^^^ ^^^^ ^^^^ ^^^^ [ ^^^^ ^^^^]< -0.2 Finally, to test if a bacterial strain is able to perform pathway (B2) the experiment can be as follows: the bacterial strain, when grown in single culture, strictly anaerobically, in Hungate tubes for at least 48 hours on YCFA, M2GSC medium or their modified form as described above, at pH 6.5-7 and 37°C, degrade at least 20% of acetate in medium, and transform at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon converted into the combined metabolites FO, LT, SU, AA, PA, BA and Et (i.e. those of FO, LT, SU, AA, PA, BA and Et which are positively accumulated) into butyrate. For example, the conditions for a bacterial strain to qualify as an acetate to butyrate converter (performing pathway B2) are: ^^^^ ^^^^ ^^^^ [ ^^^^ ^^^^] 1)^^^^ ^^^^ ^^^^ ^^^^ ^^^^ ^^^^ ^^^^ ^^^^ ^^^^ ^^^^< -0.2 A single strain can be tested for each of the above conditions to determine whether it is able to perform one or more metabolic pathway(s) such as described herein. Preferably, Agathobacter rectalis bacteria comprised in the consortium according to the invention are able to perform pathways A4 and / or B2, preferably pathways A4 and B2 such as described above. Preferably, Anaerostipes caccae bacteria comprised in the consortium according to the invention are able to perform pathways A3 and / or B2 and / or B3, preferably pathways A3, B2 and B3 such as described above. Preferably, Anaerobutyricum hallii bacteria comprised in the consortium according to the invention are able to perform pathways A3 and / or B2 and / or B3 and optionally C2, preferably pathways A3, B2 and B3 such as described above. The invention concerns consortium of anaerobic bacterial strains of an intestinal microbiome, wherein said consortium comprises of i) Agathobacter rectalis, and ii) Anaerostipes caccae and / or Anaerobutyricum hallii and no more than 15 different bacterial strains. In some embodiments, the consortium according to the invention comprises no more than 15, 14, 13, 12, 11, 10, 9,or 8 different bacterial strains. Particularly, the consortium according to the invention comprises 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 different bacterial strains, preferably 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 different bacterial strains, more preferably 8, 9, 10, 11, 12, 13, 14, or 15 different bacterial strains, and even more preferably 8 different bacterial strains. In particular, the consortium according to the invention may comprise between 5 and 15 different bacterial strains, preferably between 5 and 10 different bacterial strains, more preferably between 6 and 10 different bacterial strains, and even more preferably between 7 and 9 different bacterial strains. Preferably, the consortium comprises or consists of i) Agathobacter rectalis and ii) Anaerostipes caccae and / or Anaerobutyricum hallii and iii) one or several additional bacterial strain(s) but no more than 13, 12, 11, 10, 9, 8, 7, 6 different bacterial strains. In some embodiment, the consortium comprises i) Agathobacter rectalis and ii) Anaerostipes caccae and / or Anaerobutyricum hallii and iii) one or several bacterial strain(s) able to convert primary substrates into formate, lactate, succinate, acetate, butyrate and / or propionate, wherein the primary substrates are selected from the group consisting of sugars, starches, fibers and proteins and any combination thereof. In some embodiments, the consortium comprises one or more bacterial strains that is able to perform one or more pathways such as described above, in particular selected from the group consisting of pathways A1, A2, A3, A4, A5, A6, B1, B2, B3, B4, B5, C1 and C2, and combinations thereof. Preferably, the consortium comprises or consists of i) Agathobacter rectalis, and ii) Anaerostipes caccae and / or Anaerobutyricum hallii and iii) one or several bacterial strain(s) able to perform one or more pathways selected from the group consisting of pathway A1, A2, A3, A4, A5, A6, B1, B2, B3, B4, B5, C1 and C2, preferably A1, A2, A4, A5, A6, B1, B5, C1 and C2, even more preferably A1, A2, A4, A6, B1 and B5. Preferably, the invention concerns a consortium of no more than 15 different anaerobic bacterial strains of an intestinal microbiome, wherein said consortium comprises or consists of i) Agathobacter rectalis and ii) Anaerostipes caccae and / or Anaerobutyricum hallii and iii) between 1 and 13, preferably between 5 and 10, even more preferably between 7 and 9, different bacterial strains able to perform at least one pathway selected from the group consisting of pathway A1, A2, A3, A4, A5, A6, B1, B2, B3, B4, B5, C1 and C2, preferably A1, A2, A4, A5, A6, B1, B5, C1 and C2, even more preferably A1, A2, A4, A6, B1 and B5. In a specific embodiment, for each pathway A1, A2, A3, A4, A5, A6, B1, B2, B3, B4, B5, preferably for each pathway A1, A2, A4, A6, B1, B2, B3 and B5, one or more bacterial representatives (i.e., one or more bacterium that is representative of the specie or genus), preferably one bacterial representative, is comprised in a consortium. Also, some of the represented pathways may be accomplished by one or more than one bacterial strain. In other words, one bacterium can be able to perform a plurality of pathways and / or one pathway may be performed by one or more bacterial strains present in the consortium. In an embodiment, the consortium according to the invention comprises or consists of i) Agathobacter rectalis (performing pathway B2 and A4), and ii) Anaerostipes caccae and / or Anaerobutyricum hallii (performing pathways B2, B3, A3) and iii): - one or several bacterial strain(s) able to convert primary substrates such as sugars, starches, fibers and / or proteins into formate, (pathway A1) - one or several bacterial strain(s) able to convert primary substrates such as sugars, starches, fibers and / or proteins into lactate into acetate (pathway A2); - optionally one or several bacterial strain(s) able to convert primary substrates into butyrate (pathway A3); - one or several bacterial strain(s) able to convert primary substrates such as sugars, starches, fibers and / or proteins into lactate optionally while reducing oxygen (pathway A4 and optionally pathway C1); - optionally one or several bacterial strain(s) able to convert primary substrates into propionate (pathway A5); - one or several bacterial strain(s) able to convert primary substrates such as sugars, starches, fibers and / or proteins into lactate into succinate (pathway A6); - one or several bacterial strain(s) able to convert formate into acetate preferably able to convert of H2, CO2 and formate to acetate (pathway B1, preferably pathway C2); - optionally one or several bacterial strain(s) able to convert acetate into butyrate (pathway B2); - optionally one or several bacterial strain(s) able to convert lactate into butyrate (pathway B3) - optionally, one or several bacterial strain(s) able to convert lactate into propionate (pathway B4); and / or - one or several bacterial strain(s) able to convert succinate into propionate (pathway B5). In an embodiment, the consortium according to the invention comprises or consists of i) Agathobacter rectalis and ii) Anaerostipes caccae and / or Anaerobutyricum hallii and iii): - one or several bacterial strain(s) able to convert primary substrates such as sugars, starches, fibers and / or proteins into formate, (pathway A1) - one or several bacterial strain(s) able to convert primary substrates such as sugars, starches, fibers and / or proteins into lactate into acetate (pathway A2); - one or several bacterial strain(s) able to convert primary substrates such as sugars, starches, fibers and / or proteins into lactate optionally while reducing oxygen (pathway A4 and optionally pathway C1); - optionally one or several bacterial strain(s) able to convert primary substrates into propionate (pathway A5); - one or several bacterial strain(s) able to convert primary substrates such as sugars, starches, fibers and / or proteins into lactate into succinate (pathway A6); - one or several bacterial strain(s) able to convert formate into acetate preferably able to convert of H2, CO2 and formate to acetate (pathway B1, preferably pathway C2); - optionally, one or several bacterial strain(s) able to convert lactate into propionate (pathway B4); and - one or several bacterial strain(s) able to convert succinate into propionate (pathway B5). Preferably, said consortium does not comprise a bacterial strain able to convert lactate into propionate (pathway B4) and / or a bacterial strain able to convert primary substrates into propionate (pathway A5). Said consortium may further comprise one or several additional bacterial strains able to perform one or more pathway(s) selected from the group consisting of A3, A4, B2, B3 and any combination thereof. In some embodiments, the consortium according to the invention comprises or consists of i) Agathobacter rectalis and ii) Anaerostipes caccae and / or Anaerobutyricum hallii and iii) one or several bacterial strain(s) able to convert primary substrates into lactate. In some embodiments, the consortium according to the invention comprises or consists of i) Agathobacter rectalis and ii) Anaerostipes caccae and / or Anaerobutyricum hallii and iii): - one or several bacterial strain(s) able to convert primary substrates into formate; - one or several bacterial strain(s) able to convert formate into acetate; and / or - one or several bacterial strain(s) able to convert primary substrates into acetate. Additionally or alternatively, the consortium according to the invention comprises or consists of i) Agathobacter rectalis and ii) Anaerostipes caccae and / or Anaerobutyricum hallii and iii): - one or several bacterial strain(s) able to convert primary substrates into succinate; and / or - one or several bacterial strain(s) able to convert succinate into propionate. Additionally or alternatively, the consortium according to the invention comprises or consists of i) Agathobacter rectalis and ii) Anaerostipes caccae and / or Anaerobutyricum hallii and iii): - one or several bacterial strain(s) able to convert primary substrates into propionate; - one or several bacterial strain(s) able to convert primary substrates into succinate; and / or - one or several bacterial strain(s) able to convert succinate into propionate. In some embodiments, the consortium according to the invention comprises or consists of i) Agathobacter rectalis and ii) Anaerostipes caccae and / or Anaerobutyricum hallii and iii): - one or several bacterial strain(s) able to convert primary substrates such as sugars, starches, fibers and / or proteins into formate, (pathway A1); - one or several bacterial strain(s) able to convert primary substrates such as sugars, starches, fibers and / or proteins into lactate into acetate (pathway A2); - one or several bacterial strain(s) able to convert primary substrates such as sugars, starches, fibers and / or proteins into lactate optionally while reducing oxygen (pathway A4 and optionally pathway C1); - optionally one or several bacterial strain(s) able to convert primary substrates into propionate (pathway A5); - one or several bacterial strain(s) able to convert primary substrates such as sugars, starches, fibers and / or proteins into lactate into succinate (pathway A6); - one or several bacterial strain(s) able to convert formate into acetate preferably able to convert of H2, CO2 and formate to acetate (pathway B1, preferably pathway C2); and - one or several bacterial strain(s) able to convert succinate into propionate (pathway B5). Said consortium may further comprise one or several additional bacterial strains able to perform pathways one or more pathway(s) selected from the group consisting of A3, A4, B2, B3 and any combination thereof. Preferably, said consortium does not comprise a bacterial strain able to convert lactate into propionate (pathway B4) and / or a bacterial strain able to convert primary substrates into propionate (pathway A5). As mentioned above, bacteria can be classified by their capacities to perform metabolic pathways such as disclosed herein. In addition, below are provided examples of bacteria genera and species that are able to perform the different metabolic pathways. Then, the man skilled in the art is able to select bacteria genera or species to fulfill the conditions of the different consortiums disclosed herein. Whenever a strain is described by taxon or by reference to a public collection of microorganisms, what is claimed is the strain deposited under the accession number (e.g., ATCC, DSMZ, etc.) or strains which are closely related to the deposited strain, i.e., have the same or very similar physiological and biochemical characteristics. It is a common assumption that data obtained with one strain of a certain taxon is representative of other strains of the same taxon. For example, bacteria with a 16S rRNA sequence similarity of at least 95%, 97%, 98%, 99%, 99.5%, 99.6%, 99.7%, 99.8% or 99.9%, preferably 99.9%, are considered as belonging to the same taxon. Whenever a plurality of strains are described or claimed based on their affiliation with a genus / classification under a genus-level, the genus is defined as all strains having a 16S rRNA sequence similarity of at least 90%, 93%, 94% or 95%, preferably 95%, with a specifically listed representative of the said genus. The bacterial strain(s) being able to perform pathway (A1) may be selected from the genera Anaerobutyricum, Bacteroides, Blautia, Collinsella, Coprococcus, Dorea, Erysipelatoclostridium, Escherichia, Eubacterium, Faecalibacterium, Lachnospira, Longicatena, Ruminococcus, and Sellimonas and any combination thereof; preferably from the genera Blautia, Coprococcus, Dorea, Erysipelatoclostridium, Faecalibacterium, Lachnospira and Ruminococcus; more preferably from the genera Dorea, Faecalibacterium and Ruminococcus, even more preferably from the genus Ruminococcus. In particular, the bacterial strain(s) being able to perform pathway (A1) may be selected from the species Anaerobutyricum / Eubacterium hallii (e.g. ATCC 27751, DSM 3353, JCM 31263), Bacteroides clarus (e.g. DSM 22519, JCM 16067), Blautia hydrogenotrophica (e.g. DSM 10507, JCM 14656), Collinsella aerofaciens (e.g. ATCC 25986, DSM 3979, JCM 10188), Coprococcus eutactus (e.g. ATCC 27759), Dorea formicigenerans (e.g. ATCC 27755, DSM 3992, JCM 31256), Dorea longicatena (e.g. DSM 13814, JCM 11232), Erysipelatoclostridium ramosum (e.g. ATCC 25582, DSM 1402, JCM 1298), Eubacterium ramulus (e.g. ATCC 29099, DSM 15684, JCM 31355), Faecalibacterium prausnitzii (e.g. DSM 17677, ATCC 27768, ATCC 27766, JCM 31915), Lachnospira (Eubacterium) eligens (e.g. ATCC 27750, DSM 3376), Longicatena sp. , Ruminococcus bromii (e.g. ATCC 27255) and Sellimonas intestinalis (JCM 30749) and any combination thereof; preferably from the species Blautia hydrogenotrophica, Coprococcus eutactus, Dorea formicigenerans, Dorea longicatena, Erysipelatoclostridium ramosum, Faecalibacterium prausnitzii, Lachnospira eligens and Ruminococcus bromii; more preferably from the species Dorea formicigenerans, Dorea longicatena, Faecalibacterium prausnitzii and Ruminococcus bromii; most preferably is from the specie Ruminococcus bromii. The bacterial strain(s) being able to perform pathway (A2) may be selected from the genera Acidaminococcus, Acutalibacter, Bifidobacterium, Blautia, Clostridium, Clostridium_E, Clostridium_Q, Collinsella, Copromonas, Desulfovibrio, Dorea, Enterocloster, Escherichia, Eubacterium, Hungatella, Hungatella_A, Oliverbapstia, Peptoniphilus, Peptostreptococcus, Phocaeicola, Rhiziobiaceae genus, Ruminococcus, Sellimonas and Veillonella and any combination thereof; preferably from the genera Bifidobacterium, Blautia, Clostridium_Q, Clostridium_E, Desulfovibrio, Dorea, Eubacterium, Oliverpabstia and Rhiziobiaceae genus; more preferably from the genera Bifidobacterium, Blautia, Desulfovibrio, Dorea, Eubacterium and Rhiziobiaceae genus, even more preferably from the genus Blautia and Bifidobaterium. In particular, the bacterial strain(s) being able to perform pathway (A2) may be selected from the species Acidaminococcus intestini (e.g., DSM 21505), Acutalibacter nov. genus (in particular having a 16SRNA sequence such as set forth in SEQ ID NO: 5 and any variant thereof having at least 97%, 98% or 99% sequence identity thereto), Bifidobacterium adolescentis (e.g. ATCC 15703, DSM 20083, JCM 1251), Bifidobacterium catenulatum (e.g. ATCC 27539, DSM 16992, JCM 1194), Bifidobacterium longum (e.g. ATCC 15707, DSM 20219, JCM 1217), Bifidobacterium pseudocatenulatum (e.g. ATCC 27919, DSM 20438, JCM 1200), Bifidobacterium ruminantium (e.g. ATCC 49390, DSM 6489), Blautia hydrogenotrophica (e.g. DSM 10507, JCM 14656), Clostridium perfringens (e.g. ATCC 13124, DSM 756), Clostridium_E sporosphaeroides (e.g. ATCC 25781, DSM 1294), Clostridium_Q symbiosum (e.g. ATCC 14940, DSM 934, JCM 1297), Collinsella aerofaciens (e.g. ATCC 25986, DSM 3979, JCM 10188), Copromonas sp., Desulfovibrio piger (e.g. ATCC 29098, DSM 749), Dorea formicigenerans (e.g., ATCC 27755, DSM 3992, JCM 31256), Dorea longicatena (e.g. DSM 13814, JCM 11232), Dorea scindens, Dorea sp. 900066555, Enterocloster sp., Escherichia coli (e.g. ATCC 11775, DSM 30083, JCM 1649), Eubacterium callanderi (e.g. ATCC 49165, DSM 3662, JCM 10284), Eubacterium limosum (e.g. ATCC 8486, DSM 20543, JCM 6421, JCM 9978), Hungatella effluvii (e.g. DSM 24995), Hungatella_A sp., Oliverpabstia sp., Peptoniphilus vaginalis (e.g. DSM 101742), Peptostreptococcus anaerobius (e.g. ATCC 27337, DSM 2949), Phocaeicola plebeius (e.g. DSM 17135, JCM 12973), Rhizobiaceae nov. genus, Ruminoccocus bromii (e.g. ATCC 27255), Sellimonas intestinalis (e.g. JCM 30749) and Veillonella ratti (e.g. ATCC 17746, DSM 20736, JCM 6512) and any combination thereof; preferably from the species Bifidobacterium adolescentis, Bifidobacterium catenulatum, Bifidobacterium longum, Bifidobacterium pseudocatenulatum, Bifidobacterium ruminantium, Blautia hydrogenotrophica, Clostridium_Q symbiosum, Clostridium_E sporosphaeroides, Desulfovibrio piger, Dorea formicigenerans, Dorea longicatena, Dorea scindens, Dorea sp. 900066555, Eubacterium callanderi, Eubacterium limosum, Oliverpabstia sp. and Rhizobiaceae nov. genus; more preferably from the species Bifidobacterium adolescentis, Bifidobacterium catenulatum, Bifidobacterium longum, Bifidobacterium pseudocatenulatum, Bifidobacterium ruminantium, Blautia hydrogenotrophica, Desulfovibrio piger, Dorea longicatena, Eubacterium callanderi, Eubacterium limosum, and Rhizobiaceae nov. genus; most preferably is from the specie Bifidobacterium adolescentis or Blautia hydrogenotrophica, preferably Bifidobacterium adolescentis. The bacterial strain(s) being able to perform pathway (A3) may be selected from the genera Acidaminococcus, Agathobacter, Anaerobutyricum, Anaerostipes, Anaerotignum, Bariatricus, Clostridium, Clostridium_E, Clostridium_Q, Coprococcus, Coprococcus_A, Copromonas, Eubacterium, Faecalibacterium, Flavonifractor, Longicatena, Peptoniphilus and Roseburia and any combination thereof; preferably from the genera Acidaminococcus, Anaerobutyricum, Anaerostipes, Coprococcus, Coprococcus_A, Copromonas, Eubacterium, Faecalibacterium, Flavonifractor, Longicatena and Roseburia; more preferably from the genera Acidaminococcus, Anaerobutyricum, Anaerostipes, Copromonas, Eubacterium, Faecalibacterium, Flavonifractor, Longicatena and Roseburia, even more preferably from the genera Anaerobutyricum and Anaerostipes. In particular, the bacterial strain(s) being able to perform pathway (A3) may be selected from the species Acidaminococcus intestini (e.g., DSM 21505, CIP 108586), Agathobacter rectalis / Eubacterium rectale (e.g., DSM 17629), Agathobacter / Roseburia faecis (e.g., DSM 16840), Anaerobutyricum / Eubacterium hallii (e.g., ATCC 27751, DSM 3353, JCM 31263), Anaerostipes caccae (e.g., DSM 14662, JCM 13470), Anaerostipes hadrus (e.g., ATCC 29173, DSM 3319), Anaerotignum sp000436415, Bariatricus comes (e.g., ATCC 27758), Clostridium perfringens (e.g., ATCC 13124, DSM 756), Clostridium_E sporosphaeroides (e.g., ATCC 25781, DSM 1294), Clostridium_Q symbiosum (e.g., ATCC 14940, DSM 934, JCM 1297), Coprococcus eutactus (e.g., ATCC 27759), Coprococcus_A catus (e.g., ATCC 27761), Copromonas sp., Eubacterium ramulus (e.g., ATCC 29099, DSM 15684, JCM 31355), Faecalibacterium prausnitzii (e.g., DSM 17677, ATCC 27768, ATCC 27766, JCM 31915), Flavonifractor plautii (e.g., ATCC 29863, DSM 4000), Longicatena sp., Peptoniphilus vaginalis (e.g., DSM 101742), Roseburia hominis (e.g., DSM 16839) and Roseburia intestinalis (e.g., DSM 14610, JCM 31262) and any combination thereof; preferably from the species Acidaminococcus intestini, Anaerobutyricum / Eubacterium hallii, Anaerostipes caccae, Anaerostipes hadrus, Coprococcus eutactus, Coprococcus_A catus, Copromonas sp., Eubacterium ramulus, Faecalibacterium prausnitzii, Flavonifractor plautii, Longicatena sp., Roseburia hominis and Roseburia intestinalis; more preferably from the species Acidaminococcus intestini, Anaerobutyricum / Eubacterium hallii, Anaerostipes caccae, Anaerostipes hadrus, Eubacterium ramulus, Faecalibacterium prausnitzii, Flavonifractor plautii, Roseburia hominis and Roseburia intestinalis. The bacterial strain(s) being able to perform pathway (A4) may be selected from the genera Agathobacter, Bacteroides, Bariatricus, Bifidobacterium, Collinsella, Enterococcus, Lacticaseibacillus / Lactobacillus, Longicatena, Merdisoma, Peptostreptococcus, Roseburia, Streptococcus and Sutterella and any combination thereof; preferably from the genera Agathobacter, Bacteroides, Bariatricus, Collinsella, Enterococcus, Lacticaseibacillus / Lactobacillus, Peptostreptococcus, Streptococcus, and Sutterella; more preferably from the genera Agathobacter, Bacteroides, Bariatricus, Collinsella, Enterococcus, Lacticaseibacillus / Lactobacillus, Streptococcus and Sutterella, even more preferably is from the genus Lactobacillus or Agathobacter. In particular, the bacterial strain(s) being able to perform pathway (A4) may be selected from the species Agathobacter rectalis (e.g., DSM 17629), Agathobacter / Roseburia faecis (e.g., DSM 16840), Bacteroides clarus (e.g., DSM 22519, JCM 16067), Bacteroides faecis (e.g., DSM 24798, JCM 16478), Bacteroides uniformis (e.g., DSM 6597, ATCC 8492, JCM5828), Bariatricus comes (e.g., ATCC 27758), Bifidobacterium adolescentis (e.g., ATCC 15703, DSM 20083, JCM 1251), Collinsella aerofaciens (e.g., ATCC 25986, DSM 3979, JCM 10188), Enterococcus faecalis (e.g., ATCC 29212, DSM 2570), Enterococcus faecium (e.g., ATCC 19434, DSM 10477, JCM 8727), Enterococcus gallinarum (e.g., ATCC 49573, JCM 8728), Lacticaseibacillus rhamnosus / Lactobacillus rhamnosus (e.g., ATCC 7469, DSM 20021, JCM1136), Longicatena sp. , Merdisoma Aerosacheriphilus, Peptostreptococcus stomatis (e.g., DSM 17678, JCM 15636), Roseburia hominis (e.g., DSM 16839), Streptococcus anginosus (e.g., ATCC 33397, DSM 20563, JCM 12993), Sutterella wadsworthensis (e.g., ATCC 51579, DSM 14016) and any combination thereof; preferably from the species Agathobacter rectalis (also named Eubacterium rectale), Agathobacter faecis (also named Roseburia faecis), Bacteroides clarus, Bacteroides uniformis, Bariatricus comes, Collinsella aerofaciens, Enterococcus faecalis, Enterococcus faecium, Enterococcus gallinarum, Lacticaseibacillus rhamnosus (also named Lactobacillus rhamnosus), Peptostreptococcus stomatis, Streptococcus anginosus and Sutterella wadsworthensis; more preferably from the species Agathobacter rectalis (also named Eubacterium rectale), Bacteroides uniformis, Bariatricus comes, Collinsella aerofaciens, Enterococcus faecalis, Enterococcus faecium, Enterococcus gallinarum, Lacticaseibacillus rhamnosus (also named Lactobacillus rhamnosus), Streptococcus anginosus and Sutterella wadsworthensis; even more preferably from the specie Lactobacillus rhamnosus, Agathobacter rectalis and Bifidobacterium adolescentis, most preferably is from the specie Lactobacillus rhamnosus. The bacterial strain(s) being able to perform pathway (A5) may be selected from the genera Anaerotignum, Bacteroides, Phocaeicola and Veillonella and any combination thereof; preferably the strains are from the genus Bacteroides or Phocaeicola. In particular, the bacterial strain(s) being able to perform pathway (A5) may be selected from the species Anaerotignum lactatifermentans (e.g., DSM 14214), Anaerotignum sp000436415, Bacteroides fragilis (e.g., ATCC 25285, DSM 2151, JCM 11019), Phocaeicola vulgatus (e.g., ATCC 8482, DSM 1447, JCM 5826) and Veillonella ratti (e.g., ATCC 17746, DSM 20736, JCM 6512) and any combination thereof; preferably from Bacteroides fragilis and Phocaeicola vulgatus. The bacterial strain(s) being able to perform pathway (A6) may be selected from the genera Acutalibacter novel genus (in particular having a DNA genome sequence as set forth in SEQ ID NO: 6 or a variant of at least 90%, 95%, or 99% identity thereto and / or having a 16RNA sequence as set forth in SEQ ID NO: 5 or a variant having at least 95%, preferably at least 97%, more preferably 99%, 99.5%, 99.7% or 99.9% sequence identity thereto),, Bacteroides, Oliverbapstia, Parabacteroides, Phocaeicola and Prevotella and any combination thereof; preferably from the genera Acutalibacter nov genus, Bacteroides, Parabacteroides, Phocaeicola and Prevotella; more preferably from the genera Acutalibacter nov genus, Bacteroides, Phocaeicola and Prevotella, even more preferably from the genera Acutalibacter nov genus, Bacteroides and Prevotella, most preferably from the genera Bacteroides and Prevotella. In particular, the bacterial strain(s) being able to perform pathway (A6) may be selected from the species Acutalibacter nov. genus (in particular having a DNA genome sequence as set forth in SEQ ID NO: 6 or a variant of at least 90%, 95%, or 99% identity thereto and / or having a 16S rRNA sequence as set forth in SEQ ID NO: 5 or a variant having at least 95%, preferably at least 97%, more preferably 99%, 99.5%, 99.7% or 99.9% sequence identity thereto), Bacteroides faecis (e.g., DSM 24798, JCM 16478), Bacteroides fragilis (e.g., ATCC 25285, DSM 2151, JCM 11019), Bacteroides thetaiotaomicron (e.g., ATCC 29148, DSM 2079, JCM 5827), Bacteroides xylanisolvens (e.g., DSM 18836, JCM 15633), Oliverpabstia sp., Bacteroides faecis (e.g., DSM 24798, JCM 16478), Parabacteroides distasonis (e.g., ATCC 8503, DSM 20701), Phocaeicola dorei (e.g., DSM 17855, JCM 13471), Phocaeicola plebeius (e.g., DSM 17135, JCM 12973), Phocaeicola vulgatus (e.g., ATCC 8482, DSM 1447, JCM 5826) and Prevotella copri (e.g., DSM 18205, JCM 13464) and any combination thereof; preferably from Acutalibacter nov genus, Bacteroides faecis, Bacteroides fragilis, Bacteroides thetaiotaomicron, Bacteroides xylanisolvens, Parabacteroides distasonis, Phocaeicola dorei, Phocaeicola plebeius, Phocaeicola vulgatus and Prevotella copri; more preferably from the species Acutalibacter nov. genus, Bacteroides faecis, Bacteroides fragilis, Bacteroides thetaiotaomicron, Bacteroides xylanisolvens, Phocaeicola plebeius, Phocaeicola vulgatus and Prevotella copri; most preferably from the species Acutalibacter nov. genus (in particular having a DNA genome sequence as set forth in SEQ ID NO: 6 or a variant of at least 90%, 95%, or 99% identity thereto and / or having a 16S rRNA sequence as set forth in SEQ ID NO: 5 or a variant having at least 95%, preferably at least 97%, more preferably 99%, 99.5%, 99.7% or 99.9% sequence identity thereto), Prebotella copri and Bacteroides xylanisolvens. The bacterial strain(s) being able to perform pathway (B1) may be selected from the genera Blautia and Eubacterium; preferably from the genus Blautia. In particular, the bacterial strain(s) being able to perform pathway (B1) may be selected from the species Blautia hydrogenotrophica (e.g., DSM 10507, JCM 14656), Eubacterium callanderi (e.g., ATCC 49165, DSM 3662, JCM 10284) and Eubacterium limosum (e.g., ATCC 8486, DSM 20543, JCM 6421, JCM 9978) and any combination thereof, preferably from the specie Blautia hydrogenotrophica. The bacterial strain(s) being able to perform pathway (B2) may be selected from the genera Agathobacter, Anaerobutyricum, Anaerostipes, Anaerotignum, Desulfovibrio, Dysosmobacter, Faecalibacterium, Longicatena and Roseburia and any combination thereof; preferably from the genera Agathobacter, Anaerobutyricum, Anaerostipes, Desulfovibrio, Faecalibacterium and Roseburia. In particular, the bacterial strain(s) being able to perform pathway (B2) may be selected from the species species Agathobacter rectalis / Eubacterium rectale (e.g., DSM 17629), Agathobacter / Roseburia faecis (e.g., DSM 16840), Anaerobutyricum / Eubacterium hallii (e.g., ATCC 27751, DSM 3353, JCM 31263), Anaerostipes caccae (e.g., DSM 14662, JCM 13470), Anaerostipes hadrus (e.g., ATCC 29173, DSM 3319), Anaerotignum sp., Desulfovibrio piger (e.g., ATCC 29098, DSM 749), Dysosmobacter sp., Faecalibacterium prausnitzii (e.g., ATCC 27768, ATCC 27766,DSM 17677, JCM 31915), Longicatena sp., Roseburia hominis (e.g., DSM 16839) and Roseburia intestinalis (e.g., DSM 14610, JCM 31262) and any combination thereof; preferably Agathobacter rectalis, Anaerobutyricum hallii, Anaerostipes caccae, Anaerostipes hadrus, Desulfovibirio piger, Faecalibacterium prausnitzii, Roseburia hominis and Roseburia intestinalis; more preferably Anaerobutyricum hallii, Anaerostipes caccae and Agathobacter rectalis. The bacterial strain(s) being able to perform pathway (B3) may be selected from the genera Anaerobutyricum, Anaerostipes and Eubacterium and any combination thereof; preferably from the genera Anaerobutyricum and Anaerostipes. In particular, the bacterial strain(s) being able to perform pathway (B3) may be selected from the species Anaerobutyricum / Eubacterium hallii (e.g., ATCC 27751, DSM 3353, JCM 31263), Anaerostipes caccae (e.g., DSM 14662, JCM 13470), Eubacterium callanderi (e.g., ATCC 49165, DSM 3662, JCM 10284) and Eubacterium limosum (e.g., ATCC 8486, DSM 20543, JCM 6421, JCM 9978) and any combination thereof; preferably from Anaerobutyricum hallii and Anaerostipes caccae. The bacterial strain(s) being able to perform pathway (B4) may be selected from the genera Anaerotignum, Clostridium (Clostridium_E), Coprococcus_A, Frisingococcus and Veillonella and any combination thereof; preferably from the genera Anaerotignum genus, Coprococcus_A, Frisingococcus and Veillonella. In particular, the bacterial strain(s) being able to perform pathway (B4) may be selected from the species species Anaerotignum nov sp., Clostridium_E sporosphaeroides (e.g., ATCC 25781, DSM 1294), Coprococcus_A catus (e.g., ATCC 27761), Frisingococcus sp. , Veillonella atypica (e.g., ATCC 17744, DSM 20739), Veillonella parvula subsp. parvula (e.g., DSM 2008), Veillonella ratti (e.g., ATCC 17746, DSM 20736, JCM 6512) and any combination thereof, preferably from Anaerotignum nov sp., Coprococcus_A catus, Frisingococcus sp., Veillonella atypica and Veillonella parvula subsp. parvula. The bacterial strain(s) being able to perform pathway (B5) may be selected from the genera Dialister, Flavonifractor, Phascolarctobacterium, Phascolarctobacterium_A and Veillonella and any combination thereof; preferably from the genera Dialister, Flavonifractor and Phascolarctobacterium and Phascolarctobacterium_A, more preferably from the genus Phascolarctobacterium. In particular, the bacterial strain(s) being able to perform pathway (B5) may be selected from the species Dialister hominis (e.g., DSM 109768), Dialister invisus (e.g., DSM 15470, JCM 17566), Flavonifractor plautii (e.g., ATCC 29863, DSM 4000), Phascolarctobacterium faecium (e.g., DSM 14760), Phascolarctobacterium_A succinatutens (e.g., DSM 22533), Veillonella parvula subsp. parvula (e.g., DSM 2008) and Veillonella ratti (e.g., ATCC 17746, DSM 20736, JCM 6512) and any combination thereof, preferably from Dialister hominis, Dialister invisus, Flavonifractor plautii, Phascolarctobacterium faecium and Phascolarctobacterium_A succinatutens; more preferably from the specie Phascolarctobacterium faecium. The bacterial strain(s)s being able to perform pathway (C1) may be selected from the genera Enterococcus, Escherichia, Lacticaseibacillus / Lactobacillus, Lactococcus and Streptococcus and any combination thereof; preferably from the genera Enterococcus, Escherichia and Lacticaseibacillus. In particular, the bacterial strain(s) being able to perform pathway (C1) may be selected from the species Enterococcus caccae (e.g., ATCC BAA-1240,DSM 19114), Enterococcus faecalis (e.g., ATCC 29212, DSM 2570), Escherichia coli (e.g., ATCC 11775, DSM 30083, JCM 1649), Lacticaseibacillus rhamnosus / Lactobacillus rhamnosus (e.g., ATCC 7469, DSM 20021, JCM1136), Lactococcus lactis (e.g., ATCC 19435, DSM 20481) and Streptococcus salivarius (e.g., ATCC 7073, DSM 20560, JCM 5707) and any combination thereof; preferably from Enterococcus faecalis, Escherichia coli and Lacticaseibacillus rhamnosus. The bacterial strain(s)s being able to perform pathway (C2) may be selected from the genera Acetobacterium, Anaerobutyricum, Blautia, Candidatus Methanomassiliicoccus, Clostridium, Eubacterium and Methanobrevibacter and any combination thereof; preferably selected from the genera Anaerobutyricum, Blautia and Eubacterium. In particular, the bacterial strain(s) being able to perform pathway (C2) may be selected from the species Acetobacterium carbinolicum (e.g., ATCC BAA-990, DSM 2925), Acetobacterium malicum (e.g., DSM 4132), Acetobacterium wieringae (e.g., ATCC 43740, DSM1911, JCM 2380), Blautia hydrogenotrophica (e.g., DSM 10507, JCM 14656), Blautia producta (e.g., ATCC 27340,DSM 2950, JCM 1471), Candidatus Methanomassiliicoccus intestinalis, Clostridium aceticum (e.g., ATCC 35044, DSM 1496, JCM 15732), Clostridium glycolicum ((e.g., ATCC 14880, DSM 1288, JCM 1401), Clostridium magnum (e.g., ATCC 49199, DSM 2767), Clostridium mayombe (e.g., ATCC 51428, DSM 2767), Anaerobutyricum / Eubacterium hallii (e.g., ATCC 27751, DSM 3353, JCM 31263), Eubacterium limosum (e.g., ATCC 8486, DSM 20543, JCM 6421), Eubacterium ramulus (e.g., ATCC 29099, DSM 15684, JCM) and Methanobrevibacter smithii (e.g., ATCC 35061, DSM 861, JCM 328) and any combination thereof; preferably selected from the species Anaerobutyricum / Eubacterium hallii, Blautia hydrogenotrophica, Blautia producta, Eubacterium limosum and Eubacterium ramulus. In a further aspect, the present invention relates to a composition comprising any of the above-described consortia. Formulations and Compositions According to some aspects, the combination therapy comprises or consists of a) a first pharmaceutical or nutraceutical composition comprising the at least one bacterial strain of the invention, optionally comprised in a bacteria consortium such as described herein, and a second pharmaceutical or nutraceutical composition comprising the at least one dietary fibre and / or carbohydrate source. Alternatively, the combination therapy comprises or consists of a pharmaceutical or nutraceutical composition comprising (I) the at least one bacterial strain of the invention, optionally comprised in a bacteria consortium such as described herein, and (II) at least one dietary fibre and / or carbohydrate source. The combination therapy partners of the compositions described herein are typically selected by the method of the invention. In some aspect, the combination therapy is a symbiotic drug. As used herein the term “symbiotic drug ” or “symbiotic” refers to the association of one or more probiotic (e.g., the at least one bacterial strain(s) of the invention) with one or more prebiotic (e.g., the at least one dietary fibre and / or carbohydrate source of the invention). The idea behind symbiotics is that the prebiotics help the probiotics survive / colonize the intestine. Therefore, when bacteria useful for preventing or treating a disease or disorder caused by or related to intestinal dysbiosis are used, it is believed that the combination therapy enhances the colonization of said bacteria, promoting / enhancing its effect on gut health, metabolism and / or immune system of the treated subject. Typically, the symbiotic drug comprises at least one dietary fibre and / or carbohydrate source and at least one bacterial strain that uses preferentially said dietary fibre and / or carbohydrate source as substrate. The combined therapy may comprises 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 dietary fibres and / or carbohydrate sources. The benefit of a bacterial strain to use one or more substrate(s) can typically be assessed by the method of the invention. For example, bacterial strain of the genus Lachnospira can be combined with pea fiber, pectin and / or arabinogalactan. The composition of the invention may be a pharmaceutical composition, a food composition, a food supplement or a food additive. In preferred embodiments, the composition of the invention is a pharmaceutical composition comprising a consortium of bacterial strains such as disclosed herein and optionally a pharmaceutically acceptable carrier or excipient. Preferably, as used herein, a “pharmaceutical composition” refers to a preparation of one or more of the active agents, such as a probiotic and / or prebiotic, with optional other chemical components such as physiologically suitable carriers and excipients. Compositions of the present invention can be in a form suitable for any conventional route of administration or use. In one embodiment, a “composition” typically intends a combination of the active agent, e.g., compound or composition, and a naturally-occurring or non- naturally-occurring carrier, inert (for example, a detectable agent or label) or active, such as an adjuvant, diluent, binder, stabilizer, buffers, salts, lipophilic solvents, preservative, adjuvant or the like and include pharmaceutically acceptable carriers. Typically, the composition according to the invention comprises at least 104, at least 105, at least 106, preferably at least 107bacterial cells per ml or g for each bacterial strain and each of the bacterial strains has a viability over 10%, 20%, 30%, 40%, 50%, preferably over 70%. As used herein, the term "pharmaceutically acceptable" refers to molecular entities and compositions that do not produce an adverse, allergic or other untoward reaction when administered to a mammal, especially a human, as appropriate. Preferably, an "acceptable vehicle" or “pharmaceutically acceptable carrier” as referred to herein, is any known compound or combination of compounds that are known to those skilled in the art to be useful in formulating pharmaceutical compositions. A pharmaceutically acceptable excipient refers to a non-toxic solid, semi-solid or liquid filler, diluent, encapsulating material or formulation auxiliary of any type. The pharmaceutically acceptable excipients that can be used in the composition according to the invention are well known to the skilled person and may vary according to the disease to be treated and the administration route. In preferred embodiments, the composition of the invention is a nutraceutical composition. Preferably, the term "nutraceutical" refers to a composition or product manufactured from food substances, but made available in tablet, powder, potion or other galenic form not usually associated with food, and having a beneficial or protective physiological effect against disorders or diseases such as the one caused or related to intestinal dysbiosis. This definition includes food supplements, certain foods for specific groups and meal replacements. The combined therapy or composition of the invention can be administered by any method suitable for depositing in the gastrointestinal tract, preferably the small intestine and / or the colon, of the subject to be treated. Preferably, the combined therapy or composition of the invention is formulated either as a rectally administrated form or an orally ingestible form. Preferably, the partners of the combined therapy are or are to be administered by the same route or by different routes. Preferably, both partners are administered by the same route. Alternatively, the first partner can be administered orally and the second rectally. In an embodiment, the combined therapy or pharmaceutical or nutraceutical composition is to be administered by oral route. For oral administration, the combined therapy or pharmaceutical or nutraceutical composition can be formulated into conventional oral dosage forms such as tablets, capsules, powders, granules and liquid preparations such as syrups, elixirs, and concentrated drops. Nontoxic solid carriers or diluents may be used which include, for example, pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, sodium saccharine, talcum, cellulose, glucose, sucrose, magnesium, carbonate, and the like. For compressed tablets, binders, which are agents which impart cohesive qualities to powdered materials, are also necessary. For example, starch, gelatin, sugars such as lactose or dextrose, and natural or synthetic gums can be used as binders. Disintegrants may also be necessary in the tablets to facilitate break- up of the tablet. Disintegrants include starches, clays, celluloses, algins, gums and crosslinked polymers. Moreover, lubricants and glidants may also be included in the tablets to prevent adhesion to the tablet material to surfaces in the manufacturing process and to improve the flow characteristics of the powder material during manufacture. Colloidal silicon dioxide is most commonly used as a glidant and compounds such as talc or stearic acids are most commonly used as lubricants. Well-known thickening agents may also be added to compositions such as corn starch, agar, natural or synthetic gums, resins, methylcellulose, sodium carboxymethylcellulose, guar, xanthan and the like. Preservatives may also be included in the composition, including methylparaben, propylparaben, benzyl alcohol and ethylene diamine tetraacetate salts. Preferably, for oral administration, the composition is in a gastro-resistant oral form allowing the active compounds contained in the composition, to pass the stomach and be released into the intestine. The material that can be used in enteric coatings includes, for example, alginic acid, cellulose acetate phthalate, plastics, waxes, shellac and fatty acids (e.g., stearic acid or palmitic acid). In another embodiment, the pharmaceutical composition is to be administrated by rectal route. Suitable rectal-route forms include, but are not limited to, suppository and enema. In particular, the active compounds can be incorporated into any of the known suppository bases by methods known in the art. Examples of such bases include cocoa butter, polyethylene glycols (carbowaxes), polyethylene sorbitan monostearate, and mixtures of these with other compatible materials to modify the melting point or dissolution rate. Compositions according to the invention may be formulated to release the active ingredients substantially immediately upon administration or at any predetermined time or time period after administration. In others embodiments, the composition may be a food composition, a food supplement or a food additive, preferably a food composition or a food supplement. By “food composition" is meant any composition comprising food ingredients such as macronutrients, micronutrients, vitamins and / or minerals. The food composition may be intended for human or animal consumption and may be a liquid, paste or solid. Examples of food compositions include, but are not limited to dairy products such as cheese, butter, cream, yoghurt, fermented milk, ice cream, cooked products such as bread, biscuits and cakes, fruit products such as fruit juice, fruit compote or fruit paste, soy food products, starch-based food products, edible oil compositions, spreads, breakfast cereals, infant formula, food bars (e.g. cereal bars, breakfast bars, energy bars, nutrition bars), chewing gum, beverages, drinking supplements (powders to be added to a beverage). As used herein, the term "food supplement" refers to any composition which is formulated and administered separately from other foods to complement the nutritional intakes of a subject, i.e., a human or an animal. This supplement may be in any suitable form well known to those skilled in the art, preferably in the form of dietetic food or oral supplementation. Food supplement can typically be in the form of capsules, tablets, soft capsules, sachets, stick-packs, syrups, droppers or any other suitable form well known to those skilled in the art. As used herein, the term "food additive" refers to a composition that is intended to be mixed with one or more other foods before being administered to a subject. More specifically, "food additive" means any additive as defined by the Codex Alimentarius, General Standard for Food Additives - Codex Stan 192-1995, i.e. any substance which is not consumed alone as a foodstuff, nor used alone as a characteristic ingredient of a foodstuff, whether or not it has nutritional value, and the intentional addition of which to a food for a technological (including organoleptic) purpose at any stage of the manufacture, processing, preparation, treatment, packaging, wrapping, transport or storage of that food results, or may reasonably be expected to result, directly or indirectly, in its incorporation or that of its derivatives into that food or otherwise affect its characteristics. In some embodiments, the composition according to the invention comprises a component selected from the group consisting of cryoprotecting media, in particular comprising glycerol; culture or dispersing media, in particular comprising peptone, yeast extract, monosaccharides, disaccharides, arabinogalactan, fructo- oligosaccharides, fibers, glycerol, soluble starch, resistant starch, xylan, minerals, co-factors, vitamins and reducing agents; aqueous gels; prebiotics and polymeric supports; and any combination thereof. In some embodiments, the composition of the invention may particularly comprise one or several prebiotics. Typically, the combined therapy may comprise an additional prebiotic. Examples of additional prebiotics include, but are not limited to, complex carbohydrates, polyphenols, amino acids, peptides, minerals, or other nutritional components promoting the survival of the bacterial strains of the consortium. In some embodiments, the composition according to the invention is free of, or essentially free of succinate, formate and / or lactate. In particular, the composition according to the invention comprises succinate in an amount of less than 5 mM, formate in an amount of less than 5 mM, and / or lactate in an amount of less than 5 mM. In some embodiments, the composition according to the invention comprises propionate, acetate and / or butyrate. In particular, the composition according to the invention comprises acetate in an amount of at least 10 mM, propionate in an amount of at least 2 mM, and / or butyrate in an amount of at least 2 mM. In some embodiments, the composition of the invention comprises glycerol, in particular so as to enhance butyrate production. The effective dosage of each of the combination partners employed in the combined therapy of the invention may vary depending on the particular compound or pharmaceutical composition employed, the mode of administration, the condition being treated, the severity of the condition being treated. Thus, the dosage regimen of the combined preparation of the invention is selected in accordance with a variety of factors including the route of administration and the patient status. A physician or clinician of ordinary skill can readily determine and prescribe the effective amount of the single active ingredients required to prevent, counter or arrest the progress of an intestinal dysbiosis or of a disease or disorder caused by or related to an intestinal dysbiosis. Uses of the compositions In a further aspect, the present invention relates to the use of the combined therapy or the composition of the invention as a medicament, especially in the treatment of intestinal dysbiosis or of a disease or disorder caused by an intestinal dysbiosis. In a further aspect, the present invention relates to the use of the combined therapy or composition as a medicament, especially in the treatment of a disorder or disease, in particular caused or resulted in intestinal dysbiosis. As used herein, the term “medicament” refers to any substance or composition with curative or preventive properties against a disorder or disease. The invention also concerns a composition of the invention for use for treating a disease or a disorder, for improving the general health of a subject and / or for modifying the composition of the microbiome. It also relates to a composition for use for the manufacture of a medicament for treating a disease or disorder, for improving the general health of a subject and / or for modifying the composition of the microbiome. It also relates to the use of a composition as described herein for treating an intestinal dysbiosis or a disorder or a disease caused by or related to an intestinal dysbiosis. Then, the invention also relates to a method for treating an intestinal dysbiosis or a disorder or a disease caused by an intestinal dysbiosis, for improving the general health of a subject and / or for modifying the composition of the microbiome, comprising administering a therapeutically effective amount of a composition of the invention to a subject in need thereof. The term “dysbiosis” is known in the art and denotes the alteration of the microbiota in comparison to a healthy state. The microbiota state may be characterized by determining key markers, intermediate metabolites and end metabolites. Preferably, a healthy microbiota is characterized by the absence of intermediate metabolites. Accordingly, a state characterized by accumulation of intermediate metabolites is referred to as dysbiosis. In the context of the present invention, the dysbiosis is preferably an intestinal dysbiosis. Preferably, a subject suffers from intestinal dysbiosis when succinate is present in the intestine in an amount of at least 5 mM, 10 mM, 25 mM or 50 mM and / or formate is present in the intestine in an amount of at least 5 mM, 10 mM, 25 mM or 50 mM, and / or lactate is present in the intestine in an amount of at least 5 mM, 10 mM, 25 mM or 50 mM. The invention also relates to the use of the combination therapy or the pharmaceutical or nutraceutical composition of the invention, for the manufacture of a medicament for treating an intestinal dysbiosis or a disease or disorder caused by an intestinal dysbiosis. The invention also concerns a method for treating a patient suffering from an intestinal dysbiosis or from a disease or disorder caused by an intestinal dysbiosis, comprising administering a therapeutic amount of the combined therapy or the pharmaceutical or nutraceutical composition of the invention to said patient. Preferably, said the method further comprises a step of selecting a patient as suitable for treatment with the combined therapy or the pharmaceutical or nutraceutical composition, wherein the patient is selected as suitable if the at least one bacterial strain of the combined therapy is under-represented in the intestinal microbiome of said patient. As used herein, the term “subject” or “patient” refers to an animal such as dogs, cats, horses, cows, pigs, sheep and non-human primates or non-mammals such as poultry, preferably a mammal, more preferably a human, including adult and child. The subject to be treated with the composition of the invention is an animal, preferably a mammal. In an embodiment, the subject is a domestic or farmed animal such as dogs, cats, cows, sheep, horses or rodents. In a preferred embodiment, the subject is a human, including adult, child, newborns and human at the prenatal stage. As used herein, the terms “subject”, “individual” and “patient” are interchangeable. The term "treatment" refers to any act intended to ameliorate the health status of patients or subjects such as therapy, prevention, prophylaxis and retardation of a disease. It designates both a curative treatment and / or a prophylactic treatment of a disease. A curative treatment is defined as a treatment resulting in a cure or a treatment alleviating, improving and / or eliminating, reducing and / or stabilizing the symptoms of a disease or the suffering that it causes directly or indirectly. A prophylactic treatment comprises both a treatment resulting in the prevention of a disease and a treatment reducing and / or delaying the incidence of a disease or the risk of its occurrence. In certain embodiments, such term refers to the improvement or eradication of a disease, a disorder or symptoms associated with it. The term “treatment” includes the prevention of diseases described herein and the delay of progression of diseases described herein. A "therapeutically effective amount" is an amount which, when administered to a subject, is sufficient to treat the targeted disease or disorder, or to produce the desired therapeutic effect. This amount may vary according to the disease and its severity, the physiological data and characteristics of the patient or subject to be treated (e.g., age, size, and weight), and the routes of administration. One of skill in the art can readily identify a therapeutically or nutritionally effective amount. Preferably, an “effective therapeutic amount” comprises 103to 1014CFU (colony forming units), preferably 106to 109CFU of bacteria per ml or µg of the pharmaceutical composition. Preferably, an “effective therapeutic or nutritional amount” with regard to the fibers comprises 5-30g per day, preferably 10-25g per day, more preferably 12 -20 g per day. In general, it is desirable to provide the subject with a dosage of the above composition or consortia in the range of from about 103to 109CFU / kg, preferably 106to 109CFU / kg (body weight of the subject), although a lower or higher dosage may be administered. Alternatively, it can be desirable to provide the subject with a dosage of the composition of the invention in the range of from about 50 µg to 1 mg / kg, preferably 50 µg to 500 µg / kg, more preferably 50 µg to 250 µg / kg; even more preferably 50 µg to 100 µg / kg (body weight of the subject), although a lower or higher dosage may be administered. In embodiments wherein the disease to be treated is IBD, a therapeutically efficient amount is preferably defined as the amount necessary for having an impact on intestinal inflammation or any symptom of the disease such as diarrhea, fever or pain. The composition of the invention may be administered as a single dose or in multiple doses. In particular, depending on the subject's age or physiological condition, daily doses may be divided to facilitate administration, for example with one administration in the morning and another in the evening. In some embodiments, the composition is to be administered regularly, preferably between every day and every month, more preferably between every day and every two weeks, more preferably between every day and every week. In some particular embodiments, the composition is to be administered every day. The symbiotic composition can be co-administered. Co-administration refers to administration of more than one agent or therapy to a subject. Co-administration may be concurrent or, alternatively, one agent or material described herein may be administered in advance of or following administration of the other agent or material. The agents may be comprised in the same formulation (e.g., capsule, enema) or in separate formulations. One skilled in the art can readily determine the appropriate dosage for co-administration Also, the combination of the invention may be combined with a dietary intervention, a treatment with a drug or a medicament candidate, or a prebiotic administration. The term “drug” includes synthesized pharmaceuticals but also biopharmaceuticals or biological medical products, such as vaccines, blood components, somatic cells, gene therapies, tissues, recombinant therapeutic proteins, etc. In particular, the term “drug” includes living medicines and preferably formulations comprising bacterial cells selected or engineered to possess therapeutic properties. In some embodiments, the composition or combination of the invention may be used in combination with an antibiotic agent, an anticancer agent, selective nutrition, an agent to modulate transit time and / or for cleansing an in-situ microbiome space. The duration of treatment with the combination treatment according to the invention is preferably comprised between 1 day and 1 year, 1 day and 6 months, 1 day and 3 months or 1 day and 1 month. Alternatively, the treatment may last as long as the intestinal dysbiosis, disease or disorder persists. The duration of treatment with the composition of the invention may be comprised between 1 day and several years, preferably between 1 day and one year, more preferably between 1 day and 6 months. In some embodiments, the ratio of substrate(s):bacterial strain(s) in the combination therapy is of 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1 or 10:1. Preferably, such ratio if of gram(s) of substrate to gram(s) lyophilized bacteria. Preferably, the amount of fiber is comprised between 1g and 5g, between 1g and 10g, between 1g and 15g, between 1g and 20g, between 5g and 20g, between 5g and 15g, between 5g and 10g, between 10g and 20g, between 10g and 15g or between 15g and 20g. Preferably, these amounts are per day. The pharmaceutical compositions may find use in a number of indications such as prophylaxis, treatment, prevention or delay of progression of a disease related to intestinal microbiome disbalance or associated with microbiota dysbiosis. It is generally accepted that dysbiosis originates from an ecological disbalance (e.g., based on trophism), characterized by disproportionate amounts or absence of bacteria strains in the microbiome of the patient which are essential for the establishment and / or maintenance of a healthy microbiome. In particular, the composition of the invention can be used to treat pathologies involving bacteria of the human microbiome, preferably the intestinal microbiome, such as inflammatory or auto-immune diseases, cancers, infections or brain disorders. Inflammatory bowel diseases have been in the focus of microbiota- based therapies for some time now (Caruso et al., Host–microbiota interactions in inflammatory bowel disease. Nat Rev Immunol 20, 411–426 (2020)). Indeed, some bacteria of the microbiome, without triggering any infection, can secrete molecules that will induce and / or enhance inflammatory or auto-immune diseases (De Luca, et al., The microbiome in autoimmune diseases, Clin. Exp. Immunol. 195 (1) p. 74–85 (2019)) or cancer development (Zitvogel et al., Cancer and the gut microbiota: an unexpected link, Sci. Transl. Med.7, 271 (2015)). Recently, diseases such as rheumatoid arthritis (Maeda et al., Host–microbiota interactions in rheumatoid arthritis, Exp Mol Med, 51, 1–6 (2019)) and multiple sclerosis (Correale et al., The role of the gut microbiota in multiple sclerosis, Nat Rev Neurol 18, 544–558 (2022)) have increasingly come into focus in microbiome research. Therefore, disease or disorder to be treated by the composition according to the invention may, in particular, be a dysbiosis i) following antibiotics treatment, ii) following exacerbated immune response, or iii) associated with cancer. In some embodiments, the disorder may be selected from the group of dysbiosis following antibiotics treatment, infection by vancomycin resistant enterococci (VRE), infection by carbapenem resistant enterococci (CRE), post-infectious diarrhea; inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn’s disease (CD); rheumatoid arthritis (RA); multiple sclerosis (MS); graft versus host disease (GvHD); solid and liquid cancer, in particular gastrointestinal cancer, colorectal cancer (CRC), acute myeloid leukemia (AML); gastritis, colitis, gastroenteritis, gingivitis, nosocomial infection and Clostridium difficile infection (CDI). In a particular embodiment, the disease or disorder to be treated is selected from dysbiosis following antibiotics treatment, infection by vancomycin resistant enterococci, infection by carbapenem resistant enterococci; inflammatory bowel disease, including ulcerative colitis and Crohn’s disease; rheumatoid arthritis; multiple sclerosis; graft versus host disease; solid and liquid cancer, in particular gastrointestinal cancer, colorectal cancer and acute myeloid leukemia. The composition according to the invention may be used in combination with another therapy or treatment for intestinal dysbiosis or a disease or disorder related to intestinal dysbiosis. In some aspects, the intestinal dysbiosis is caused by an antibiotic treatment. Preferably, the disease or disorder caused by or related to intestinal dysbiosis is selected from the group consisting of an inflammatory disease, an auto-immune disease, a cancer, a bacterial infection and a brain disorder, preferably in from the group consisting of infection by vancomycin resistant enterococci (VRE), infection by carbapenem resistant enterococci (CRE), post-infectious diarrhea; Parkinson’s disease (PD), herosclerotic cardiovascular disease (ACVD), coronary artery disease (CAD), hypertension inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohns’s disease (CD); impaired glucose tolerance (IGT), type 1 diabetes (T1D), type 2 diabetes (T2D), rheumatoid arthritis (RA); multiple sclerosis (MS); graft versus host disease (GvHD); gastrointestinal cancer, adenoma, colorectal cancer (CRC), acute myeloid leukemia (AML); gastritis, colitis, gastroenteritis, gingivitis, nosocomial infection and Clostridium difficile infection (CDI). In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus Lachnospira, especially of a species described herein, and (II) pea fiber, pectin and / or arabinogalactan, preferably pectin; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of complications post-hematopoietic stem cell transplantation (HSCT), in particular graft versus host disease (GvHD). In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus Lachnospira, especially of a species described herein, and (II) pea fiber, pectin and / or arabinogalactan, preferably pectin; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of acute myeloid leukemia (AML). In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus Lachnospira, especially of a species described herein, and (II) pea fiber, pectom and / or arabinogalactan, preferably pectin; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of inflammatory bowel disease (IBD). In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus Ruminococcus_D, especially of a species described herein, and (II) pea fiber; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of inflammatory bowel disease (IBD). In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus Ruminococcus_D, especially of a species described herein, and (II) pea fiber; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of acute myeloid leukemia (AML). In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus Ruminococcus_D, especially of a species described herein, and (II) pea fiber; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of impaired glucose tolerance (IGT) and / or type 1 diabetes (T1D). In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus UMGS1375 (Hominsplanchenecus), especially of a species described herein, and (II) arabinogalactan, resistant dextrin and / or pectin, preferably arabinogalactan and / or pectin; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of inflammatory bowel disease (IBD). In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus UMGS1375 (Hominsplanchenecus), especially of a species described herein, and (II) arabinogalactan, resistant dextrin and / or pectin, preferably arabinogalactan and / or pectin; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of acute myeloid leukemia (AML). In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus Blautia_A, especially of a species described herein, and (II) xylan; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of inflammatory bowel disease (IBD). In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus Blautia_A, especially of a species described herein, and (II) xylan; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of cancer, in particular colorectal cancer (CRC). In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of I) a bacterial strain of the genus Blautia_A, especially of a species described herein, and (II) xylan; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of impaired glucose tolerance (IGT), type 1 diabetes (T1D) or type 2 diabetes (T2D). In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus Blautia_A, especially of a species described herein, and (II) xylan; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of Atherosclerotic cardiovascular disease (ACVD), coronary artery disease (CAD) and / or hypertension . In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus Parabacteroides, , especially of a species described herein, and (II) resistant dextrin and / or yeast extract; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of colorectal cancer (CRC) and / or complications of post-hematopoietic stem cell transplantation (HSCT), in particular graft versus host disease (GvHD) In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus Acutalibacter, especially of a species described herein, and (II) resistant dextrin; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of adenoma and / or colorectal cancer (CRC). In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus Akkermansia, especially of a species described herein, and (II) mucin; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of colorectal cancer (CRC) and / or Parkinson’s disease (PD) In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus Agathobacter, especially of a species described herein, and (II) pea fiber, resistant dextrin, mucin and / or xylan, preferably pea fiber; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of complications post-hematopoietic stem cell transplantation (HSCT), in particular graft versus host disease (GvHD). In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus Agathobacter, especially of a species described herein, and (II) pea fiber, resistant dextrin, mucin and / or xylan, preferably pea fiber; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of acute myeloid leukemia (AML). In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus CAG-41, especially of a species described herein, and (II) pea fiber and / or pectin, resistant dextrin, mucin and / or xylan, preferably pea fiber; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of acute myeloid leukemia (AML). In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus TF01-11, especially of a species described herein, and (II) pea fiber; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of acute myeloid leukemia (AML) and / or of complications post-hematopoietic stem cell transplantation (HSCT), in particular graft versus host disease (GvHD). In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus Acetatifactor, especially of a species described herein, and (II) arabinogalactan, pea fiber, soluble starch and / or xylan, preferably pea fiber; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of acute myeloid leukemia (AML) or of complications post- hematopoietic stem cell transplantation (HSCT), in particular graft versus host disease (GvHD). In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus Fusicatenibacter, especially of a species described herein, and (II) xylan; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of acute myeloid leukemia (AML) or of complications post-hematopoietic stem cell transplantation (HSCT), in particular graft versus host disease (GvHD). In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus Anaerostipes, especially of a species described herein, and (II) yeast extract; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of inflammatory bowel disease (IBD). In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus Anaerostipes, especially of a species described herein, and (II) yeast extract; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of impaired glucose tolerance (IGT) and / or type 1 diabetes (T1D). In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus Eisenbergiella, especially of a species described herein, and (II) resistant dextrin; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of colorectal cancer (CRC). In some aspects, the combination therapy, the bacteria consortium or the pharmaceutical or nutraceutical composition comprises or consists essentially of (I) a bacterial strain of the genus Eisenbergiella, especially of a species described herein, and (II) resistant dextrin; preferably wherein the combination therapy, bacteria consortium, pharmaceutical or nutraceutical composition is for use in the treatment of type 2 diabetes (T2D). Methods of production The invention also concerns a method for producing the consortium or composition such as disclosed herein in an appropriate culture medium. The terms “dispersing medium”, “cultivation medium” and “culture medium” are used interchangeably herein and refer to a liquid or solid medium, preferably a liquid medium, in which one or several bacterial strains can be inoculated and / or cultivated. The composition of the culture medium depends on the nutritional requirements of the cultivated bacteria. This composition can be easily adjusted by the skilled person based on his general knowledge. Typically, culture media include at least one carbon source (glycerol, glucose, galactose, maltose, lactose, sucrose, fructose, cellobiose), fibers (preferably pectin, arabinogalactan, beta-glucan, soluble starch, resistant starch, fructo-oligosaccharides, galacto-oligosacharides, xylan, arabinoxylans, cellulose), proteins (preferably yeast extract, casein, skimmed milk, peptone), co-factors (short chain fatty acids, hemin, FeSO4), vitamins (preferably biotin, cobalamin, 4-aminobenzoic acid, folic acid, pyridoxamine hydrochloride), minerals (preferably sodium bicarbonate, potassium phosphate dibasic, potassium phosphate monobasic, sodium chloride, ammonium sulfate, magnesium sulfate, calcium chloride) and reducing agents (preferably cysteine, titanium(III)-citrate, yeast extract, sodium thioglycolate, dithiothreitol, sodium sulphide, hydrogen sulphite, ascorbate). Culture media can also comprise compound(s) preventing microbial contamination, e.g., antibiotics selected to be inefficient on desired bacteria. The skilled person can easily adjust the culture medium to the nutritional requirements of the bacteria to be cultivated. A broad range of solid or liquid culture media are known and may be used in the context of the present invention. Suitable media include liquid media and solid supports. Liquid media generally comprise water and may thus also be termed aqueous media. Solid media may comprise a polymeric support such as agar. Preferably, the culture medium is a liquid culture medium. In a particular embodiment, the culture media comprises amicase, yeast extract, mineral solution, potassium phosphate, sodium chloride, ammonium sulfate, magnesium sulfate, calcium chloride nutriose, inulin, soluble potato starch, cellobiose, hemin, resazurin, vitamin, cystein, HCl and / or NaHCO3. In particular embodiments, the producing method of the invention is performed in a reactor. By “reactor” is meant a conventional tank or any apparatus or system for fermentation and / or bioconversion, typically selected from bioreactors, biofilters, rotary biological contactors, and other gaseous and / or liquid phase bioreactors. The apparatus which can be used according to the invention can be used continuously or in batch loads, for example for batch or fed-batch fermentation. Batch cultivation such as in an anaerobic batch or fed-batch fermentation process is known to be particularly suitable for large-scale production of bacteria and bacteria consortia. The invention thus also concerns a reactor or bioreactor comprising a consortium or composition as defined herein. Preferably, the method of production is conducted under anaerobic conditions. In some embodiments, the method according to the invention, the bacterial strains are cultured / multiplied by co-cultivation in an anaerobic batch fermentation process or in an anaerobic fed-batch fermentation process. The term “batch fermentation” is known and denotes a fermentation process in a bioreactor, wherein during the fermentation process no material is removed from nor added to the bioreactor. In this text, the term “batch fermentation” in particular denotes a fermentation process, wherein there is no removal of a culture suspension cultivated in the bioreactor with the exception of insignificant amounts required for analytical testing, and wherein there is no addition of fresh culture medium into the bioreactor. Furthermore, a flow of gaseous compounds into and out of the bioreactor during the fermentation process, for example inflow of inert gas to maintain anaerobic cultivating conditions or such as outflow of metabolic exhaust gas, are not considered as material added or removed from the bioreactor. The term “fed-batch fermentation” is known and denotes a fermentation process in a bioreactor, wherein during the fermentation process no material, in particular no-culture suspension is removed from the bioreactor, except for insignificant amounts required for analytical testing and except for gaseous compounds. However, in a fed-batch fermentation process, material is added to the bioreactor during the fermentation process, in particular fresh culture medium is added. The added culture medium may be the same or different culture medium as the culture medium in the bioreactor at the beginning of the fed-batch fermentation process. In the method of the invention, the consortium may be amplified from an inoculum. Preferably, the bacterial strains are in the form of an inoculum from a prior continuous anaerobic co-cultivation process. As used herein, the term “inoculum” refers to a sample containing viable bacteria, intended to be introduced into an environment favorable to its multiplication, preferably a suitable culture medium, in order to produce a greater quantity of said viable bacteria or to produce a compound produced by said bacteria, for example such as butyrate. The culture is preferably conducted in an industrial scale, i.e., in particular above 200 ml, above 300 ml or above 500 ml and more preferably in a volume of at least 1 L, at least 10 L, at least 30 L, at least 50 L, at least 100 L, at least 250 L or at least 500 L. The terms “continuous culture”, “continuous cultivation” and “continuous co-cultivation” are known and refer to a cultivation of bacterial strains in a bioreactor comprising a liquid culture medium wherein during the cultivation process, materials are added and removed. In particular, the term “continuous culture” refers to a cultivation process wherein fresh medium replaces an equal volume of effluent of culture-suspension at a constant flow rate during the cultivation process. The method according to the invention may further comprise the harvest or collection of the consortium, in particular after multiplication. The method according to the invention may further comprise one or more post-treatment step. The term “post treatment” preferably refers to a further processing step or downstream treatment, such as for example a preservation treatment. The post-treatment can be cryopreservation or lyophilization. In some embodiments, the method of the invention comprises a cryopreservation step and comprising: - mixing the harvested culture-suspension with a cryoprotective solution, in particular in order to obtain a 1:1 (v / v) mixture of culture-suspension and cryopreservant, preferably glycerol, or - centrifuging the harvested culture-suspension and resuspending an obtained pellet in a mixture of the cryoprotective solution and the dispersing medium, in particular in a 1:1 (v / v) mixture of cryopreservant, preferably a mixture of glycerol and dispersing medium, and - shock freezing with liquid N2 or gradually freeze to a storage temperature of at least -20°C, in particular at -20°C to -80°C. In another embodiment, the post-treatment is lyophilization comprising the steps of: - centrifuging the harvested culture-suspension and washing the obtained pellet with a buffer solution; - resuspending the pellet in a lyophilization solution and lyophilizing; and - subsequently, storing at a temperature of 4°C or lower, or at room temperature. In a very particular embodiment, the method of manufacturing the consortium or composition as defined herein, comprises the following steps: I. providing a sample of the consortium of bacterial strains as an inoculum from a prior continuous anaerobic co-cultivation process; II. adding the inoculum to a dispersing medium in a bioreactor thereby forming a culture- suspension of the bacterial strains; III. multiplying the bacterial strains in the culture suspension by co-cultivation in an anaerobic batch fermentation process or in an anaerobic fed-batch fermentation process; IV. optionally harvesting the consortium of bacterial strains; and V. optionally, subjecting the harvested consortium to one or more post-treatment steps such as cryopreservation or lyophilization. In some embodiments, such method further comprises a step of harvesting the consortium of bacterial strains. In some embodiments, such method additionally comprises a step of subjecting the harvested consortium to one or more post-treatment steps such as cryopreservation or lyophilization, in particular as described hereabove. Kits Compositions of the disclosure can be packaged as a kit. Then, the invention also provides a kit comprising the combined therapy of the invention in particular for the preparation of a composition such as disclosed herein. In some embodiments, the kit may additionally comprise instructions for cultivation / multiplication of the at least one bacterial strain or consortium according to the invention, in particular when the bacterial strain or consortium is provided in the kit as an inoculum. The kit may additionally comprise a substrate or prebiotic comprising: - one or more dietary fibre selected from the group consisting of resistant dextrin (RD), pectin (PE), pea fibre (PF), and arabinogalactan (AG); and / or - one or more carbohydrate source selected from the group consisting of soluble starch (SS), xylan (XY), yeast extract (YE), mucin (MU). The kit of the invention typically comprises a probiotic (e.g., the at least one bacterial strain optionally comprised in a consortium) and a prebiotic (e.g., one or more dietary fibre and / or carbohydrate source). The probiotic and prebiotic may be provided as two separate compositions or in a single composition. In a particular embodiment, the kit may take the form of a single sachet having two compartments intended to receive each of the two different ingredients (i.e., prebiotic and probiotic) of the combined therapy according to the invention separately. The kit may additionally comprise instructions for preparing the combined therapy, pharmaceutical or nutraceutical composition such as disclosed herein. The kit may alternatively comprise a composition comprising the at least one bacterial strain or consortium of the invention, in particular a pharmaceutical composition, together with the corresponding substrate of the invention. In some embodiments, the kit may include a composition as an already prepared dosage form ready for administration or, alternatively, can include a composition comprising the at least one bacterial strain or microbial consortium as described herein as a solid composition (e.g., in a lyophilized form) that can be reconstituted with a solvent to provide a liquid dosage form or as an inoculum for cultivation purposes, together with the corresponding substrate of the invention. In some embodiments, the kit is for use in treating, preventing, ameliorating, reducing or delaying the onset of an intestinal dysbiosis or of a disease or disorder related to an intestinal dysbiosis, such as a disease or disorder selected from the group consisting of Crohn's disease, inflammatory bowel disease, gastritis, colitis, ulcerative colitis, irritable bowel syndrome, cancer including gastro-intestinal cancer or colorectal cancer (CRC), ulcers such as gastric ulcer or duodenal ulcer, intestinal infections such as caused by viruses or bacteria, auto-immune disease, gastroenteritis, Guillain-Barre syndrome, graft versus host disease (GvHD), gingivitis, nosocomial infection, Clostridium difficile infection (CDI), infection by vancomycin resistant enterococci VRE) and post-infectious diarrhea; preferably selected from the group consisting of inflammatory bowel diseases (IBD), ulcerative colitis (UC) and Crohn's disease (CD). Preferably, the disease or disorder is selected from the group consisting of an inflammatory disease, an auto- immune disease, a cancer, a bacterial infection and a brain disorder, preferably in from the group consisting of infection by vancomycin resistant enterococci (VRE), infection by carbapenem resistant enterococci (CRE), post-infectious diarrhea; inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohns’s disease (CD); rheumatoid arthritis (RA); multiple sclerosis (MS); graft versus host disease (GvHD); gastrointestinal cancer, colorectal cancer (CRC), acute myeloid leukemia (AML); gastritis, colitis, gastroenteritis, gingivitis, nosocomial infection and Clostridium difficile infection (CDI). In some embodiments, the kit of the invention may additionally comprise instructions for using the kit in treating an intestinal dysbiosis or of a disease or disorder related to an intestinal dysbiosis, such as described herein. Instructions supplied in the kits of the invention are typically written instructions on a label or package insert (e.g., a paper sheet included in the kit in the form of a leaflet or instruction manual). In particular, the disclosure relates to a method for establishing a combination therapy for modulating an intestinal microbiome. This specification also refers to a method for establishing a combination therapy for modulating an intestinal microbiome, comprising the steps of: a) Providing a microbiome sample distributed into at least two microbiome test samples, b) Growing a first microbiome test sample of step (a) on a reference substrate; c) Determining an absolute or relative abundance of individual microbe population in the first microbiome test sample at the end of step (b); d) Growing a second microbiome test sample of step (a) on a substrate comprising a nutritionally or therapeutically effective amount of - dietary fibers selected from the group of resistant dextrin RD, pectin PE, pea fiber PF, and arabinogalactan AG; or - a carbohydrate source selected from the group of soluble starch SS, xylan XY, yeast extract YE, mucin MU; e) Determining an absolute or relative abundance of individual microbe population in the second microbiome test sample at the end of step (d); f) Determining microbe population differentially enriched between the first and the second test sample by subtracting the absolute or relative abundance of an individual microbe population of step c) from the absolute or relative abundance of the same individual microbe population of step e); g) Attributing the enriched microbe population of step (f) to a specific substrate selected from the group of resistant dextrin RD, pectin PE, pea fiber PF, and arabinogalactan AG; or selected from the group of soluble starch SS, xylan XY, yeast extract YE, mucin MU; h) Developing a pharmaceutical or nutritional combination for modulating an intestinal microbiome, said combination comprising (I) at least the enriched microbe population of step f); and (II) the substrate to which the enriched microbe population was attributed to in step f). Disclosed herein are also - - a pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, preferably as described above, wherein combination comprises, in each case, a pair of (a) nutritional substrate and (b) at least one bacterial taxon from a specific list identified by the described method. - a pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, said combination comprising (i) a fiber selected from the group of resistant dextrin (RD), pectin (PE), pea fiber (PF), and arabinogalactan (AG) (ii) at least one bacterial strain identified in a method described herein. -_ a pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, said combination comprising (i) a dietary fiber selected from the group of resistant dextrin RD, pectin PE, pea fiber PF, and arabinogalactan; or a carbohydrate source selected from the group of soluble starch SS, xylan XY, yeast extract YE, mucin MU AG (ii) at least one bacterial strain identified in a method described above.. - a pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, said combination comprising (a) at least one bacterial strain selected from the genera Acutalibacter, Parabacteroides, Fusicatenibacter, Clostridium_A, Eisenbergiella, UMGS1375, Agathobacter, Murimonas and Ruminococcus_A; (b) resistant dextrin (RD, e.g. Nutriose).Preferably, the bacterial strain is selected from Acutalibacter timonensis, Acutalibacter sp003612555, Parabacteroides distasonis, Parabacteroides merdae, Fusicatenibacter saccharivorans, Clostridium_A leptum, Eisenbergiella sp900066775, Eisenbergiella massiliensis, Eisenbergiella tayi, UMGS1375 sp900066615, Agathobacter rectalis, Agathobacter faecis, Murimonas intestini, Ruminococcus_A sp000437095, Ruminococcus_A sp003011855. - a pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, said combination comprising (a) at least one bacterial strain selected from the genera CAG-41, UMGS1441, Lachnospira, CAG-274 and UMGS1375; b) pectin (PE). Preferably, the bacterial strain is selected from CAG-41 sp900066215, UMGS1441 sp900551755, Lachnospira eligens, Lachnospira rogosae, Lachnospira sp003451515, Lachnospira sp003537285, and UMGS1375 sp900066615. - a pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, said combination comprising (a) at least one bacterial strain selected from the genera CAG-41, TF01-11, UMGS1441, Lachnospira, Ruminiclostridium_E, Agathobacter, Acetatifactor, Ruminococcus_D, Kineothrix; (b) pea fiber (PF). Preferably the bacterial strain is selected from CAG-41 sp900066215, TF01-11 sp001414325, UMGS1441 sp900551755, Lachnospira rogosae, Lachnospira sp003537285, Ruminiclostridium_E siraeum, Agathobacter faecis, Agathobacter rectalis, Acetatifactor sp900066365, Ruminococcus_D bicirculans, Ruminococcus_D sp900604945, Kineothrix alysoides. - a pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, said combination comprising (a) at least one bacterial strain selected from the genera UMGS1375, Olsenella_E, Murimonas, Acetatifactor, Lachnospira; (b) arabinogalactan (AG). Preferably, the bacterial strain is selected from UMGS1375 sp900066615, Olsenella_E sp003609875, Murimonas intestini, Acetatifactor sp900066565, Lachnospira eligens. - a pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, said combination comprising (i) a carbohydrate source selected from the group of soluble starch SS, xylan XY, yeast extract YE, mucin MU (ii) at least one bacterial strain identified in a method disclosed above. - a pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, said combination comprising (a) at least one bacterial strain selected from the genera UMGS1375, Akkermansia, Ruminococcus_E, GCA-900066135, Eubacterium_G, Agathobacter, Barnesiella, Mediterraneibacter, CAG-45; (b) mucin (MU). Preferably, the bacterial strain is selected from UMGS1375 sp900066615, Akkermansia muciniphila, Ruminococcus_E bromii, GCA-900066135 sp900066135, Eubacterium_G ventriosum, Eubacterium_G sp000434315, Agathobacter faecis, Agathobacter rectalis, Barnesiella intestinihominis, Mediterraneibacter faecis, Mediterraneibacter torques, CAG-45 sp900066395. - a pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, said combination comprising (a) at least one bacterial strain selected from the genera Anaerostipes, Parabacteroides, Phascolarctobacterium_A, Bacteroides, Phascolarctobacterium; (b) yeast extract (YE). Preferably, the bacterial strain is selected from Anaerostipes sp90006670, Parabacteroides merdae, Phascolarctobacterium_A succinatutens, Bacteroides faecichinchillae, Bacteroides ovatus, Phascolarctobacterium faecium. - A pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, said combination comprising (a) at least one bacterial strain selected from the genera Agathobacter, Roseburia, Coprococcus, CAG-45, Acetatifactor, Ruminococcus_E; (b) soluble starch (SS). Preferably, the bacterial strain is selected from Agathobacter rectalis, Agathobacter faecis, Roseburia intestinalis, Roseburia sp001940165, Coprococcus eutactus, CAG-45 sp900066395, Acetatifactor sp900066365, Ruminococcus_E sp003438075. - A pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, said combination comprising (a) at least one bacterial strain selected from the genera Agathobacter, Blautia_A, Bifidobacterium, Fusicatenibacter, Acetatifactor, Murimonas; and (b) xylan (XY). Preferably, the bacterial strain is selected from Agathobacter rectalis, Blautia_A sp003471165, Blautia_A sp003471165, Bifidobacterium adolescentis, Fusicatenibacter saccharivorans, Acetatifactor sp900066565, Murimonas intestini. Typically, the at least one bacterial strain is comprised in a bacterial consortium comprising: - one or several bacterial strain(s) able to convert primary substrates into lactate (A4); - one or several bacterial strain(s) able to convert lactate into butyrate (B3); and / or - one or several bacterial strain(s) able to convert lactate into propionate (B4). Additionally or alternatively, the at least one bacterial strain is comprised in a bacterial consortium comprising: - one or several bacterial strain(s) able to convert primary substrates into formate (A1); - one or several bacterial strain(s) able to convert primary substrates into acetate (A2); - one or several bacterial strain(s) able to convert formate into acetate (B1); and / or - one or several bacterial strain(s) able to convert acetate into butyrate (B2). Additionally or alternatively, the at least one bacterial strain is comprised in a bacterial consortium comprising: - one or several bacterial strain(s) able to convert primary substrates into succinate (A6); and / or - one or several bacterial strain(s) able to convert succinate into propionate (B5). In another aspect, the specification relates to a pharmaceutical or nutritional combination for modulating an intestinal microbiome, in particular for use in the treatment of intestinal dysbiosis, preferably as described above, wherein the at least one bacterial strain of combination is comprised in a bacterial consortium comprising 5 to 15 bacterial strains. The additional bacterial strains may be chosen for their metabolic function. For example, the bacterial strain of the combination may be comprised in a bacterial consortium comprising - one or several bacterial strain(s) able to convert primary substrates into formate (A1); - one or several bacterial strain(s) able to convert primary substrates into acetate (A2); - one or several bacterial strain(s) able to convert format into acetate (B1); - one or several bacterial strain(s) able to convert acetate into butyrate (B2); - one or several bacterial strain(s) able to convert primary substrates into lactate (A4); - one or several bacterial strain(s) able to convert lactate into butyrate (B3); - one or several bacterial strain(s) able to convert lactate into propionate (B4); - one or several bacterial strain(s) able to to convert primary substrates into succinate (A6); and / or - one or several bacterial strain(s) able to convert succinate into propionate (B5). Particularly, - the one or several bacterial strain(s) able to convert primary substrates into lactate (A4) transform at least 30%, at least 50%, more preferably at least 60% of the total carbon transformed into the combined metabolites formate (FO), lactate (LT), succinate (SU), acetate (AA), butyrate (BA), propionate (PA) and Ethanol (Et) into lactate when grown for 48 hours in single culture on standard medium; - the one or several bacterial strain(s) able to convert lactate into butyrate (B3) degrade at least 20% of lactate in medium and transform at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Et into butyrate when grown for 48 hours in single culture on standard medium supplemented with lactate; - the one or several bacterial strain(s) able to convert lactate into propionate (B4) degrade at least 20% of lactate in medium and transform at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Et into propionate when grown for 48 hours in single culture on standard medium supplemented with lactate. - the one or several bacterial strain(s) able to convert primary substrates into formate (A1) transform at least 20%, at least 25%, more preferably at least 30% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Et into formate when grown for 48 hours in single culture on standard medium; - the one or several bacterial strain(s) able to convert primary substrates into acetate (A2) transform at least 30%, at least 50%, more preferably at least 60% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Et into acetate when grown for 48 hours in single culture on standard medium; - the one or several bacterial strain(s) able to convert formate into acetate (B1) degrade at least 20% of formate in medium and transform at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Et into acetate when grown for 48 hours in single culture on standard medium supplemented with formate; - the one or several bacterial strain(s) able to convert acetate into butyrate (B2) degrade at least 20% of acetate in medium and transform at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Ethanol into butyrate when grown for 48 hours in single culture on standard medium or standard medium supplemented with FO, LT and / or SU. - the one or several bacterial strain(s) able to convert primary substrates into succinate (A6) transform at least 30%, at least 50%, more preferably at least 60% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Et into succinate when grown for 48 hours in single culture on standard medium; - the one or several bacterial strain(s) able to convert succinate into propionate (B5) degrade at least 20% of succinate in medium and transform at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Et into propionate when grown for 48 hours in single culture on standard medium supplemented with succinate. Preferably, - the one or several bacterial strain(s) able to convert primary substrates into lactate (A4) are selected from the genera Agathobacter, Bacteroides, Bariatricus, Bifidobacterium, Collinsella, Enterococcus, Lacticaseibacillus / Lactobacillus, Longicatena, Merdisoma, Peptostreptococcus, Roseburia, Streptococcus and Sutterella; preferably from the genera Agathobacter, Bacteroides, Bariatricus, Collinsella, Enterococcus, Lacticaseibacillus / Lactobacillus, Peptostreptococcus, Streptococcus, and Sutterella; more preferably from the genera Agathobacter, Bacteroides, Bariatricus, Collinsella, Enterococcus, Lacticaseibacillus / Lactobacillus, Streptococcus, and Sutterella; - the one or several bacterial strain(s) able to convert lactate into butyrate (B3) are selected from the genera Anaerobutyricum, Anaerostipes and Eubacterium; preferably from the genera Anaerobutyricum and Anaerostipes; - the one or several bacterial strain(s) able to convert lactate into propionate (B4) are selected from the genera Anaerotignum, Clostridium, Coprococcus_A, Frisingococcus and Veillonella; preferably from the genera Anaerotignum genus, Coprococcus_A, Frisingococcus and Veillonella. - the one or several bacterial strain(s) able to convert primary substrates into formate (A1) are selected from the genera Anaerobutyricum, Bacteroides, Blautia, Collinsella, Coprococcus, Dorea, Erysipelatoclostridium, Escherichia, Eubacterium, Faecalibacterium, Lachnospira, Longicatena, Ruminococcus, and Sellimonas; preferably from the genera Blautia, Coprococcus, Dorea, Erysipelatoclostridium, Faecalibacterium, Lachnospira and Ruminococcus; more preferably from the genera Coprococcus, Dorea, Faecalibacterium and Ruminococcus; - the one or several bacterial strain(s) able to convert primary substrates into acetate (A2) are selected from the genera Acidaminococcus, Acutalibacter, Bifidobacterium, Blautia, Clostridium, Clostridium_E, Clostridium_Q, Collinsella, Copromonas, Desulfovibrio, Dorea, Enterocloster, Escherichia, Eubacterium, Hungatella, Hungatella_A, Oliverbapstia, Peptoniphilus, Peptostreptococcus, Phocaeicola, Rhiziobiaceae genus , Ruminococcus, Sellimonas and Veillonella; preferably from the genera Bifidobacterium, Blautia, Clostridium_Q, Clostridium_E, Desulfovibrio, Dorea, Eubacterium, Oliverpabstia, and Rhiziobiaceae genus; more preferably from the genera Bifidobacterium, Blautia, Clostridium_E, Desulfovibrio, Dorea, Eubacterium, and Rhiziobiaceae genus; - the one or several bacterial strain(s) able to convert formate into acetate (B1) Blautia and Eubacterium; - the one or several bacterial strain(s) able to convert acetate into butyrate (B2) may be selected from the genera Agathobacter, Anaerobutyricum, Anaerostipes, Anaerotignum, Desulfovibrio, Dysosmobacter, Faecalibacterium, Longicatena and Roseburia; preferably from the genera Agathobacter, Anaerobutyricum, Anaerostipes, Desulfovibrio, Faecalibacterium and Roseburia. - one or several bacterial strain(s) able to convert primary substrates into succinate (A6) are selected from the genera Acutalibacter, Bacteroides, Oliverbapstia, Parabacteroides, Phocaeicola and Prevotella; preferably from the genera Acutalibacter nov genus, Bacteroides, Parabacteroides, Phocaeicola and Prevotella; more preferably from the genera Acutalibacter nov genus, Bacteroides, Phocaeicola and Prevotella; - one or several bacterial strain(s) able to convert succinate into propionate (B5) are selected from the genera Dialister, Flavonifractor, Phascolarctobacterium and Veillonella; preferably from the genera Dialister, Flavonifractor, Phascolarctobacterium and Phascolarctobacterium_A. The bacteria consortium preferably comprises or essentially consists of Agathobacter rectalis; Anaerostipes caccae or Anaerobutyricum hallii; Ruminococcus bromii; Bifidobacterium adolescentis; Lactobacillus rhamnosus; Blautia hydrogenotrophica; Phascolarctobacterium faecium and a bacterium selected from the group consisting of Bacteroides xylanisolvens, Prevotella copri and Acutalibacter species having at least 95% identity with SEQ ID NO:6, preferably the bacteria consortium comprises or essentially consists of Agathobacter rectalis; Anaerostipes caccae; Ruminococcus bromii; Bifidobacterium adolescentis; Lactobacillus rhamnosus; Blautia hydrogenotrophica; Phascolarctobacterium faecium and a bacterium selected from the group consisting of Bacteroides xylanisolvens, Prevotella copri and a Acutalibacter nov. species. In particular, the bacteria consortium comprises or consists of: - Agathobacter rectalis; Anaerostipes caccae; Ruminococcus bromii; Bifidobacterium adolescentis; Lactobacillus rhamnosus; Blautia hydrogenotrophica; Phascolarctobacterium faecium and Bacteroides xylanisolvens; - Agathobacter rectalis; Anaerostipes Caccae; Ruminococcus bromii; Bifidobacterium adolescentis; Lactobacillus rhamnosus; Blautia hydrogenotrophica; Phascolarctobacterium faecium and Prevotella copri; or - Agathobacter rectalis; Anaerostipes Caccae; Ruminococcus bromii; Bifidobacterium adolescentis; Lactobacillus rhamnosus; Blautia hydrogenotrophica; Phascolarctobacterium faecium and a Acutalibacter species having at least 95% identity with SEQ ID NO 6. Preferably, the bacteria consortium comprises between 5 and 15 different bacterial strains, preferably between 6 and 10 different bacterial strains. In some instances, the bacteria consortium is comprised in a composition further comprising: - propionate, acetate and / or butyrate; - a pharmaceutical excipient or carrier; and / or - a component selected from the group consisting of cryoprotecting media, in particular glycerol; culture or dispersing media, in particular comprising peptone, yeast extract, monosaccharides, disaccharides, arabinogalactan, fructo-oligosaccharides, fibers, glycerol, soluble starch, resistant starch, xylan, minerals, co-factors, vitamins and reducing agents; aqueous gels; prebiotics and polymeric supports; and any combination thereof. Preferably, the dysbiosis is associated with an antibiotics treatment or an inflammatory or auto-immune disease, cancer, infection or brain disorder; in particular the disease or disorder may be selected from the group of infection by vancomycin resistant enterococci (VRE), infection by carbapenem resistant enterococci (CRE), post-infectious diarrhea; inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohns’s disease (CD); rheumatoid arthritis (RA); multiple sclerosis (MS); graft versus host disease (GvHD); solid and liquid cancer, in particular gastrointestinal cancer, colorectal cancer (CRC), acute myeloid leukemia (AML); gastritis, colitis, gastroenteritis, gingivitis, nosocomial infection and Clostridium difficile infection (CDI). The combination is typically for simultaneous or consecutive administration. All the references cited in this description are incorporated by reference in the present application. Others features and advantages of the invention will become clearer in the following examples which are given for purposes of illustration and not by way of limitation. BRIEF DESCRIPTION OF THE FIGURES The invention will be better understood when consideration is given to the figures and the following detailed description thereof. Figure 1a: Microbiome activity and Niche Mapping. The goal is to map gut bacteria into the functional niches of the gut. The inventors use carbon fermentation as a biochemical scaffold, where each primary resource (e.g. dietary fibers) or secondary resource (e.g. fermentation intermediates) represents a niche. Figure 1b: Experimental setup. Whole fecal microbiota that span the entire enterotype spectrum are enriched in a basal medium that is supplemented with a panel of complex carbon sources. Metabolites are measured after 48 h of activity, and the composition is determined with 16S amplicon sequencing. The inventors statistically partition the readouts into three components: the activity from the basal medium, the activity specific to the carbon source, the donor-substrate specific deviation. Figure 1c: Metabolic output with regard to total carbon per substrate. The carbon flux into the measured metabolites varies by supplemented substrate. The bars show the estimated mean across all donors,. Figure 1d: PE and RD particularities. Donor microbiota M1 and M8 are particularly efficient at metabolizing resistant dextrin (RD) and are comparatively poor at metabolizing pectin (PE), and vice-versa for M3 and M4. The circles show the posterior means, the thick lines the posterior 50% and the thin lines the 95% highest probability density intervals. Figure 1e: The substrate-specific bacterial growth [cells / ml] between substrates. The substrate-specific bacterial growth [cells / ml] between substrates. The bars show the posterior mean increase in biomass across all donors. The ordering of the substrates is the same as in panel c. Figure 1f: Total bacterial growth. The observed metabolic trade-off between RD and PE is not recapitulated for total bacterial growth. Figure 1g: Compositional change per donor sample. The eight microbiota retain a strong compositional signature of the fecal sample after enrichment. Each point shows the top two principal components (PC) of the bacterial composition at the end of an enrichment from a donor fecal inoculum in an individual growth substrate. Figure 1h: Functional guilds and context dependency. The inventors postulate that the observed commonalities and differences in total metabolic activity and bacterial growth can be mapped back to either (A) the occurrence of functional guilds, wherein each fecal microbiome might have its own specific guild member, or (B) that the niches are filled by the same bacteria across fecal donors, but that the remaining biotic context modulates the activity and growth. Figure 2a: The primary substrates each select for specific characteristic taxa: Overview of the approach. The inventors compute the selection for a specific taxon k, As,kand the absolute growth, Bs,kin a substrate s . The stochastic effects from the initial dilution are accounted for probabilistically by computing p0 , p1 , and p2, Xs,k,iis the relative abundance of taxon k in replicate i of substrate s. ms,iis the estimated total bacteria of replicate i in substrate s. Based on these values, the inventors identify characteristic taxa that are specifically selected for on a substrate. The inventors then use the variation in degree of selection A across donor microbiota and correlations between taxa to interpret how much context dependence and / or guild structure plays a role. Figure 2b: Bacterial growth, most enriched taxa per substrate. The characteristic genera for a substrate are above a threshold for unspecific growth and corresponding selection. Most characteristic genera are specific to one (or two) substrates, though some are selected for across almost all substrates. Figure 2c: The bars show the mean selection across all donors and the circles show the respective values in a single donor. Figure 2d: The bars show the coefficient of variation (CV) of A across donors Figure 3a: Metabolite accumulation per substrate. The metabolic output differs by added substrate. The bars show the mean concentration of the respective metabolite across all donors. The large colored circles indicate donor-specific deviations that are significantly different from zero (posterior probability < 0.1). The small black dots show the other donors. Concentrations are shown in mM carbon. FO: formate, LT: lactate, SU: succinate, AC: acetate, BU: butyrate, PR: propionate. Figure 3b: Comparison of single strain metabolism vs community output, Pectin. The metabolic output of the characteristic taxon for pectin (PE), Lachnospira eligens, matches the metabolic output of the whole community. L. eligens was in monoculture on the PE-supplemented medium in the same conditions as the fecal samples. Figure 3c: Comparison of single strain metabolism vs. community output, RD. The metabolic output of the characteristic strain for resistant dextrin (RD), Acutalibacer sp. only partially matched that of the average fecal community. The lower panel shows the pairwise Spearman correlations of the measured metabolites across the RD enrichments with a strong anticorrelation between SU and PR. Because SU is typically converted only to PR they are combined for a better match to the profile of the characteristic taxon. Figure 3d: Succinate conversion per donor sample. Enrichments in basal medium supplemented with SU reveal a binary pattern of SU consumption by the fecal microbiota. Positive values show the concentration of produced metabolites and negative values consumed metabolites. Figure 3e: Succinate consumption guilds. Three genera were identified as characteristic for SU consumption, with a strong binary pattern across the 5 microbiota for which SU consumption was observed. The heatmap shows the relative abundances of each of the characteristic genera in the 8 fecal samples. Fecal microbiota that consumed SU typically had one dominant representative of the three characteristic taxa, non-consuming microbiota did not have any or only very subdominant abundances (black rectangles) Figure 3g: Lactate conversion. Metabolic output of enrichments in basal medium supplemented with lactate (LT). Figure 3h: Four genera were identified as characteristic for LT consumption, with only Anaerobutyricum and Coprococcus_A widely present across donor microbiota. Figure 4a: Microbiota changes in a nutritional intervention study with resistant dextrin. Healthy participants in the study supplemented their otherwise normal diet daily for 4 weeks with either NUTRIOSE®(resistant dextrin; RD) or maltodextrin as a control (Ctrl). Fecal samples were collected at the start and end of the study and analyzed with 16S amplicon sequencing. Figure 4b: Most enriched taxa in nutritional study. Only few genera were differentially changed during the study in the RD group compared to the Ctrl group. Genera that increased significantly in relative abundance in the RD group from start to end of the study (dark circles). The corresponding change in the Ctrl group is shown with light circles. Figure 4c and d: Correlation of in vitro and in vivo study. Of all enrichment conditions, only RD correlated significantly with the changes observed in the nutritional intervention study. The bars show the Pearson correlation between in vitro enrichment and in vivo change in relative abundance. The error bars for the estimated confidence interval for the correlation coefficient. The overall magnitude across all substrates of Parabacteroides enrichment in vitro is low, but is most strong on RD compared to the other dietary fibers and sugars. Figure 4e: Parabacteroides in vitro enrichment per substrate. The magnitude of selection of individual genera predicts the change in relative abundance in the study. Figure 5: Microbiomes are organized into niches in a hierarchical manner that follow the scaffold of thermodynamic energy flow. Microbiome taxa can be mapped onto a metabolic reaction scaffold with three trophic levels. Complex primary degraders are at the top level and break down complex energy sources like dietary fibers. The mapping of taxon-to-fiber is highly specific. At the middle level are simple sugar / substrate utilizers. The phylogenetic diversity at this level is high with some guild-like properties. Finally, at the bottom level are secondary consumers. The mapping of taxon-to-niche is also highly specific but with some redundancy that manifests is a strong guild structure. Energy flow and accessibility is determined top-down, while the context that directs the metabolic output is determined bottom-up. Figure 6A-D: Gram Stains of isolated strains suitable for the invention. Fig 6A: Eisenbergiella species, isolated and disclosed by 16S rRNA sequence (SEQ ID No.1), formate and butyrate producer; Fig 6B: Eisenbergiella species, isolated and disclosed by 16S rRNA sequence (SEQ ID No.2), formate and butyrate producer; Fig 6C: CAG-274 species, isolated and disclosed by 16S rRNA sequence (SEQ ID No.4), acetate and formate producer; Fig 6D: UMGS1375 species, isolated and disclosed by 16S rRNA sequence (SEQ ID No.3), acetate and succinate producer. Figures 8-27:Bacterial genera which are underrepresented in patient cohorts suffering form a specific disease in comparison to a cohort of healthy volunteers. EXAMPLES Example 1: The total metabolic output is more strongly determined by carbon source than microbiome composition The inventors premise is that competition for the different extrinsic and intrinsic resources ultimately determines which bacteria thrive and are metabolically active in the gut. Extrinsic resources comprise those parts of the diet that are not digested or absorbed prior to arrival in the relevant portion of the human gastrointestinal tract (typically the colon), as well as different host and microbial glycans, peptides, and other nutrients. Focusing on dietary fibers, these are hydrolyzed into simpler building blocks and converted via fermentative pathways into different fermentation products. The most frequent fermentation intermediate products are formate, lactate, and succinate, and typical fermentation end products are acetate, butyrate, and propionate (Figure 1a). The inventors experimentally simulated the outcomes of competition for extrinsic and intrinsic resources using diluted fecal samples from eight different human fecal donors in a defined base medium supplemented with a panel of substrates that are representative of the extrinsic dietary components subject to colonic fermentation: fibers (arabinogalactan, AG; pectin, PE; pea fiber, PF; resistant dextrin, RD), simpler polysaccharides (xylan, XY; soluble starch, SS), and glycosylated proteins (mucin, MU; yeast extract, YE). The inventors standardized the media to contain 3 g / L of extrinsic carbon, corresponding to roughly 100 mM supplemented carbon atoms for each of the substrates. To cover a broad range of possible bacterial responses, the inventors chose fecal donors with microbiome compositions that span the entire enterotype diversity with respect to Bacteroides, Prevotella, and Ruminococcus. With this setup at hand, the inventors first asked whether the tested microbiomes differed in terms of the realized car bon flux, that is, their overall capacity to convert the primary substrates into fermentation products. The inventors estimated the carbon flux from each of the extrinsic carbon sources using a Bayesian approach (see Methods). Briefly, the inventors assumed a total of 100 mM supplemented car bon for all substrates and computed the proportion of the carbon that ended up in the measured metabolites formate, lactate, succinate, acetate, butyrate, propionate, and ethanol. The inventors then partitioned the carbon flux into three components (Figure 1b): (i) the carbon flux from the basal medium for a donor d, ξd; (ii) the carbon flux from the specific extrinsic substrate s, ϕs; and (iii) the deviation from the mean carbon flux on substrate s for each donor d, ψd,s. High values of ϕs imply extrinsic substrates that are readily metabolized by the fecal microbiota, while low values suggest substrates that are more recalcitrant. Conversely, a high or low value of ψd,s identifies a donor microbiota d that is particularly efficient or poor at metabolizing the extrinsic substrate s, respectively, compared to the average donor microbiota. The substrates differed strongly in terms of the mean carbon flux, ϕs (Figure 1c) that was achieved after 48 h. The highest carbon flux was from the structurally simple polysaccharides, soluble starch (simple glucose polymers; ϕSS = 55.5 %) and xylan (simple xylose polymers; ϕXY = 60.6 %). The carbon flux from the dietary fibers decreased with increasing structural complexity: pectin (complex soluble mix of rhamnose and galactose) and resistant dextrin (glucose polymers with resistant osidic linkages) were the highest among fibers (ϕPE = 42.4 %, ϕRD = 39.5 %, followed by pea fiber (soluble and insoluble fibers including pectin, cellulose, and xyloglucans; ϕPF = 33.7 %) and arabinogalactan (mix of arabinose and galactose; ϕAG = 27.3 %). This hierarchy of the substrates follows the expectation that structural complexity and solubility influences fermentability. The identity of the microbiota had a much smaller effect on carbon flux than the type of supplemented substrate. Individual donor microbiota deviated from the mean carbon flux between −6.6 % (M5 on YE) to 6.1 % (M4 on PE), implying that the donor microbiota all had similar capacities to metabolize the different extrinsic substrates. This was also true in terms of their capacity to metabolize the basal medium. Hence, despite strong differences in composition across the tested microbiota, the overall functional output was largely conserved. The inventors asked whether the large differences in realized carbon flux between substrates (up to 3x) was the result of differences in bioavailability between the substrates, or alternatively the result of a trade-off between catabolism and anabolism, where lower carbon fluxes into metabolites implied a higher carbon flux into growth. The inventors thus estimated the amount of bacterial growth across the different supplemented substrates as cells / ml based on the extracted DNA concentration calibrated to total cell counts with qPCR (see Methods). The inventors then used the same partitioning approach into mean substrate effects and donor- specific deviations as for carbon flux (Figure 1b). Lower bioavailability implies that those substrates with lower carbon flux also had lower biomass yield. In contrast, a shift from metabolite production to biomass production implies that substrates with high carbon flux into metabolites would have lower biomass production, and vice versa. The different primary substrates differed substantially in terms of how much bacterial growth they supported (Figure 1d), but the ranking did not correlate with that for carbon flux into metabolites (Spearman’s r = 0.476, p = 0.243). While some substrates with high carbon flux into metabolites also had a high biomass yield (e.g. SS, 6.5-fold increase in biomass over the basal medium), others did not (e.g., XY, 3.2-fold). Conversely, some substrates with intermediate carbon flux had particularly high biomass yields (RD, 5.4-fold) while others had lower yields (PE, 2.9-fold). Overall, there was no consistent mapping of carbon flux to growth, but rather each substrate was characterized by its own unique allocation into metabolite production and growth. The unique signature of carbon flux and growth in each substrate suggested that different biochemical processes (enzymes, pathways, etc.) might be at play—and potentially also different taxa. The inventors hypothesized that if the same taxa were responsible for metabolizing a substrate across donors, then the microbiome compositions at the end of each of the enrichments should converge and cluster by substrate more strongly than by donor. However, the different fecal donor microbiota strongly retained their initial differences in composition throughout the enrichments (Figure 1g). Thus, either the donor specific compositional signal is much stronger in magnitude than the changes of the specific taxa that are responsible for metabolizing a substrate, or otherwise each donor has its own specific taxon—or group of taxa—for each functional role. The inventors observed some notable differences between donor microbiota in specific cases (1c,d). Most of these significant donor specific deviations pertained to either RD or PE, with an apparent trade-off between the two (asterisk in Figure 1c). Microbiota with a high carbon flux in RD had a low flux in PE (e.g. M7 and M1), and conversely, microbiota with a high flux in PE had a low flux in RD (Spearman’s r = −0.91, p = 0.001; Figure 1f). This suggests that there are indeed properties of microbiome composition that make it more proficient in one function, but less so in another. The trade-off between RD and PE, however, was not re capitulated for bacterial growth (Figure 1g; Spearman’s r = −0.09, p = 0.84), and more generally carbon flux did not trade-off with bacterial growth, expect for PE (Spearman’s r = −0.81, p = 0.0218). The structural complexity of the substrate was thus the main determinant of carbon flux into metabolites. Nevertheless, some yet uncharacterized donor specific effects led to differences in bacterial growth and metabolic activity. To help explain these observations, the inventors turned to two principles from ecological theory (Figure 1h). First, different bacteria could be responsible for the same function and therefore might be grouped into functional guilds. Small differences in how these bacteria express the function could then result in subtle differences in carbon flux and growth. Second, the same taxa could be responsible for a certain function, but because of differences in the background composition—i.e. the microbiome context—the breakdown products are metabolized in a slightly different way, again resulting in subtle differences in terms of carbon flux and growth. To investigate which of the two scenarios was more consistent with the data, the inventors turned to the compositional changes that occurred during the enrichments. Example 2: Each growth substrate has ‘characteristic taxa’ that are mostly conserved across microbiota The inventors first verified that the basal culture conditions themselves did not bias bacterial growth unevenly across donor fecal samples. Next, the inventors identified putative ‘characteristic taxa’ that are drivers of the differential activity signals across substrates by determining two quantities for each taxon: (i) the degree of selection in substrate s, As, and (ii) the absolute growth, Bs. The inventors estimated As as the log2-fold increase in absolute abundance in a specific substrate relative to the basal medium, and Bs as the difference in absolute abundance between enrichments in substrate s and the basal medium without supplemented substrate (Figure 2a). To reduce the compositional complexity, the inventors grouped all the 1579 amplicon sequence variants (ASVs) into 231 phylogenetically coherent genera (GTDB taxonomy; see Methods). The mean absolute growth of genera across substrates had a bimodal distribution with a separation between the two peaks at around BT = 5 × 10^6cells / mL. The inventors interpreted the lower peak as unspecific growth and defined BT as a cut-off for specific growth. For each substrate, the inventors then determined the genera that were more strongly selected for than those below the threshold BT and were expected to be in the inoculum of at least two donors (n = 86; Figure 2b). For YE, no genera were above the cutoff. Because the basal medium already contains yeast extract as a source of essential amino acids, cofactors, etc., additionally supplementing additional yeast extract likely did not specifically select for additional taxa. The A values of the characteristic taxa did not correlate with the abundance of the respective genera in the inoculum samples (Spear man’s r = −0.0468, p = 0.422) and thus the inventors concluded that these were not a priori biased by differences in starting abundances. Overall, this procedure identified 29 out of 86 genera as characteristic for at least one substrate. Each substrate had its own distinct set of characteristic genera. Most of the characteristic genera were only associated with one or two substrates ( Figure 2b). The strongest selection occurred on PE and PF and these substrates overlapped in their characteristic genre, with the genus cluster CAG-41 (Clostridia class) and UMGS1441 (Lachnospirales order) among the top 3 in both substrates (Figure 2c). This overlap in characteristic taxa likely reflects the similarity between the two substrates, as PF contains pectins and the known pectin-utilizing genus Lachnospira (e.g. L. eligens, L. pectinoschiza) was also strongly selected for in both PE and PF. For RD, the characteristic genera were particularly unique, including Acutalibacter, Clostridium_A, and Eisenbergiella. The characteristic taxa the inventors identified included those that are expected from the literature. MU selected for Akkermansia and Barnesiella, both canonical mucin degraders, SS selected for the starch-utilizers Agathobacter, Roseburia, Coprococcus, and Ruminococcus_E (i.e. R. bromii), and XY selected for Bifidobacterium amongst others. Having identified the characteristic taxa for each of the substrates, the inventors asked whether they exhibited signatures of functional guilds and / or context dependence. On the one hand, if different characteristic taxa were to make up a functional guild, then at least two of them should have both considerable variation and a negative correlation in their A values across donors. On the other hand, if the variation in metabolic output is driven by context dependence, then there should be few characteristic taxa per substrate and these should not have any anti-correlation with the other taxa (Figure 2a). The characteristic genera with the highest A values were the most consistent across fecal donors. The coefficient of variation (CV ) was generally lower than 1 (Figure 2d), implying that the amount of variation was lower than the magnitude of selection. The CV also generally decreased with increasing A (Spearman’s r = −0.583, p = 1.08 × 10−5). This was particularly evident for PE, PF, and RD, underlining the specificity of fiber degradation. Nevertheless, some of the specific characteristic genera had high CVs compared to the others (e.g. Acutalibacter on RD, or UMGS1375 and Akkermansia on MU). Example 3: The dominant characteristic taxa are predictive of the metabolic output of the microbiota. With the characteristic taxa at hand, the inventors next asked whether the metabolic activities of these bacteria can explain the overall community metabolic output on the different substrates (Figure 3a). To this end the inventors selected two pure isolates that matched the characteristic taxa of RD and PE. For RD, the inventors isolated an Acutalibacter sp. (strain PB-SMJER) after enrichment of a fecal sample from donor M7 on RD. For PE, the inventors selected a Lachnospira eligens (strain PB-SJATG) that had previously been isolated from a fecal sample that was enriched in a medium high in pectins. The inventors then measured the concentration of metabolites in terms of moles carbon produced by these two ‘characteristic strains’ on PE and RD, respectively. The metabolites produced by the characteristic taxa matched those produced by the whole fecal microbiota. In PE, L. eligens produced acetate (26.6 mM carbon) and formate (9.0 mM carbon) at a molar carbon ratio of 3:1. This was consistent with what was observed across all the fecal microbiota (Figure 3b; mean acetate = 30.2 mM carbon, formate = 8.0 mM carbon, ap prox. molar carbon ratio 3.77:1). In RD, Acutalibacter sp. produced acetate (9.2 mM carbon) and succinate (13.9 mM carbon) at a molar carbon ratio of 2:3 (Figure 3c). This did not match the metabolite profiles across donors, where propionate and butyrate was also produced (Figure 3c). Propionate production was bimodal across donors, with 10-14 mM carbon in some (M1, M3, M7, M8) and 0-4 mM carbon in the others (M2, M4, M5, M6). Succinate concentrations were strongly anti correlated with propionate along the same bimodal partitioning of donors (Figure 3c). Because propionate is the typical fermentation product of the succinate pathway, the inventors hypothesized that this dichotomy was the result of incomplete succinate utilization in those four microbiota for which succinate was measured. To test this, the inventors performed additional enrichments using succinate as the supplemented carbon source. Enrichments of the fecal microbiota in succinate supplemented medium (SU) also had a binary pattern of succinate consumption and propionate production. Succinate was consumed by five of the eight donor microbiota (M1, M3, M6, M7, M8) and was converted to propionate at a molar ratio of 1:1, but was not consumed at all by the remaining three microbiota (Figure 3d). This binary pattern of succinate consumption / propionate production almost perfectly matched the binary pattern the inventors observed on RD, confirming that the accumulation of succinate was due to the inability of those donor microbiota to consume the succinate produced from RD. Example 4: Strong guild structures arise at the secondary consumer level To further understand the dichotomy of succinate consumption on a taxonomic level, the inventors determined the characteristic taxa for succinate using an equivalent procedure as for the primary substrates. After filtering for unspecific growth, the inventors identified only three characteristic genera for SU consumption (Figure 3e), all of which belong to the Negativicutes class that is known for the ability to consume succinate. Within donor microbiota, only a single characteristic genus was respectively enriched—or none at all: Phascolarctobacterium in M1 and M3, Phascolarctobacterium_A in M7 and M8, and UBA1822 (Dialisteraceae family) in M6. Such strong mutual exclusivity is a hallmark of functional guilds, and the inventors thus postulated that these three genera form a functional guild for SU consumption. In this case, the abundance of the functional guild as a whole in the diluted fecal sample should determine whether SU accumulates or is consumed. Having observed the prominent guild structure for SU consumption the inventors asked whether this was also true for the other intermediate metabolites, and performed equivalent enrichments for formate (FO) and lactate (LT). FO was not consumed during the 48h cultures in these specific culture conditions. In contrast, LT was fully consumed by all eight microbiota and was primarily converted to butyrate (Figure 3g). The inventors did, however, observe differential propionate production from LT across donor microbiota, with 3-6 mM produced in five microbiota (M1, M2, M4, M7, M8) and none produced in the remaining three (M3, M5, M6). The inventors identified four characteristic genera for LT consumption, of which Anaerobutyricum and Coprococcus_A were selected for across almost all microbiota (8 / 8 and 7 / 8, respectively). These two genera are known LT consumers but use different pathways, where Anaerobutyricum (e.g. A. hallii) produces butyrate and Coprococcus_A (e.g. C. catus) produces propionate. The more strongly that Coprococcus_A was selected for, the more propionate was produced (Spear man’s r = 0.786, p = 0.048), suggesting that Coprococ cus_A is a key driver of propionate production from LT. Inspired by the SU guild, the inventors hypothesized that Anaerobutyricum and Coprococcus_A would directly compete for LT. However, the A were not anti- correlated (Spearman’s r = 0.551, p = 0.157) suggesting some mechanism for coexistence of these two characteristic genera. In M4, Coprococcus_A was absent and instead Frisingicoccus was selected for. Frisingicoccus is a direct phylogenetic neighbor of Coprococcus_A, such that it likely uses the same metabolic pathways for LT which could explain the observed propionate production in M4 without Coprococcus_A. Thus, while guilds are not as evident at first glance for LT as for SU, a guild-like structure does emerge among those LT consumers that employ similar metabolic pathways. Example 5: A nutritional intervention study confirms the characteristic taxa for resistant dextrin The characteristic taxa provide predictions of which bacteria are stimulated by different components of human diet. To test these predictions, the inventors made use of microbiome data from a placebo controlled randomized nutritional intervention study using RD. Briefly, individuals were given either RD (NU TRIOSE®) or maltodextrin—a placebo that is completely metabolized in the small intestine (Figure 4a). Fecal samples were collected prior to the start of the study and after four weeks of dietary supplementation, and their composition was analyzed using 16S amplicon sequencing (see Methods). Four weeks of supplementation with RD resulted in a larger change in the microbiota of study participants compared to supplementation with the placebo. However, the overall microbiota diversity did not change significantly in either group. Both these results are consistent with those from a similar nutritional intervention study with NUTRIOSE®. Only two genera, Acutalibacter and Parabacteroides, significantly increased over the four weeks in the RD group compared to the placebo group (Figure 4b), with Parabacteroides and Acutalibacter increasing from a mean relative abundance of 0.5% and 0.2% at baseline to 3.4% and 3.0% in the RD group at the end of the study, respectively. Additional genera increased by a degree that was significantly higher than zero, but not significantly different from the placebo group in the statistical sense: Merdibacter, Fusicatenibac ter, Clostridium_A, and Eisenbergiella (Figure 4c). The genera that increased in the microbiota of study participants after four weeks of RD supplementation was in good agreement with the characteristic taxa of RD from the in vitro enrichments. The inventors compared the degree of selection for genera measured in vitro to the change in relative abundance in the study participants over the four weeks of RD supplementation. To avoid comparing taxa that were not present in the donor microbiota, the inventors computed the expected number of donor inocula out of the eight that contained a genus of interest, p2, and only included those with p2 > 1. RD was the only in vitro substrate for which the estimated degree of selection correlated significantly with the changes in the patients (Figure 4c; Pearson’s r = 0.45, p = 9.92 × 10−7). Almost all of the characteristic taxa identified in vitro were also selected for in the human participants during the course of the study (Figure 4e). The exception was Parabacteroides, which was strongly selected for in the study participants, but was not among the characteristic genera for RD. This was because the overall selection for Parabacteroides in vitro was low in magnitude but was nevertheless strongest for RD compared to all the other tested dietary fibers (Figure 4d). This suggests that the predictions are specific for those taxa that supplementation with RD (i.e. NUTRIOSE®) selects for in humans. Example 6: Interpretation A major impediment to manipulating and engineering gut microbiomes is the lack of a good catalog that maps the different microbial constituents of intestinal bacteria to their respective functional roles. Inspired by approaches from chemical engineering, the inventors and others have put forward blueprints of how microbes might be organized and reconstructed based on a desired metabolic output. Yet, without a systematic mapping of bacteria onto the different roles that make up these blueprints, such approaches retain an ad hoc nature. Most transcriptomes, or other meta-omes to actual phenotypes is challenging, and further projecting this into a community context is typically unfeasible. The approach the inventors present here circumvents many of these obstacles by directly measuring bacterial metabolic phenotypes in their relevant complex community context. The inventors demonstrated the power of the inventor’s approach by identifying the characteristic bacteria that are associated with specific parts of intestinal carbohydrate fermentation. The characteristic taxa the inventors identified comprised both expected taxa as well as novel taxa. For example, the Lachnospira the inventors identified as characteristic for pectin are known to be “pectinophilic”, but the inventors were also able to map the more elusive genera UMGS1441 and CAG-41 to pectin degradation. CAG-41 is an unclassified Firmicutes bacterium that was first identified in MetaHIT32, and since then has been repeatedly reported as differentially abundant, e.g. between health and disease. Similarly, UMGS1441 has most recently been assembled from metagenomic data from chickens (Candidatus Gallispira). For AG, the top characteristic genera included an unclassified genus of Lachnospiraceae (here Lachnospiraceae_Genus) and UMGS1375. Lachnospiraceae_Genus grouped together ASVs whose closest BLAST hit was L. eligens at < 95 % identity. The ASVs that grouped into UMGS1375 were a close match (97 %-99 % identity) to Hominisplanchenecus faecis, a genus that was only very recently isolated using an automated high-throughput approach but not yet characterized. The characteristic genera for RD, Acutalibacter and Eisenbergiella, have been observed in gut microbiomes, though their role has remained unclear so far, and Clostridium_A (e.g. C. leptum / Cluster IV ) has been a group of interest for over a decade. The inventors were thus able to map an important part of key intestinal bacteria across human fecal microbiomes onto the biochemical scaffold for carbohydrate fermentation—the assumption being that this is a good representation of the key metabolic role of the microbiome. Doing so allowed us to attribute the concepts of context-dependence and functional guilds from ecological theory to the observed structure and further refine the functional blueprint for gut microbiomes. The premise is that intestinal micro biomes are organized in a trophic hierarchy, with different organizational structures at each trophic level (Figure 5). ‘Complex primary degraders’ break down chemically complex energy sources, such as dietary fibers, of ten doing so extracellularly and thus releasing the simple building blocks to the local environment. On the next level, the resulting simple sugars are further metabolized by ‘simple primary degraders’, into either fermentation intermediates or end products. Because the final steps of the fermentation cascade typically provide less energy to the microbe, intermediate products—in particular, formate, lactate, and succinate—are often released back into the environment. At the bottom level, secondary consumers are specialized in the conversion of these fermentation intermediates into fermentation end products, mostly short-chain fatty acids. The inventors here develop an understanding of how these trophic units are organized. Each of the trophic units have a unique combination of taxonomic diversity, guild structure, and niche diversity. The taxonomic diversity within a niche follows a ‘bell shape’, with few taxa associated with complex primary substrates and secondary consumers, and higher diversity in the simple substrate consumers (Figure 5). At the top trophic level, complex carbohydrates with high heterogeneity in chemical structure require a repertoire of various enzymes to break down the different kinds of glycosidic bonds. At the bottom trophic level, the metabolic reactions are often rather specific in terms of the physiochemical environment (pH, redox, etc.) and the energetic yields are low. Both extrinsic constraints impose a high degree of evolutionary selection that limits diversification. At the middle level, the main metabolic processes revolve around the common fermentative pathways that are broadly distributed. Guild structure is weakest at the complex primary de grader level. The breadth of substrate types combined with the specialization required to degrade a particular substrate result in few taxa that sufficiently overlap in terms of their substrate repertoire to lead to competitive exclusion. Examples for this in the data is the conservation of the CAG-41 and Lachnospira for PE, and Acutalibacter for RD. At the simple sugar level, diversity is too high to allow for a clean guild structure to emerge— a multitude of gut bacteria can utilize sugar monomers (glucose, galactose, xylose, etc.) as an energy source. Finally, at the secondary consumer level, guilds are very pronounced, possibly also because the low energetic yield increases the perceived competition for energy. The inventors observed that typically only a single succinate consumer was dominant per fecal microbiome, and that the function ‘broke down’ if the whole guild was absent. Surprisingly, for lactate the inventors observed coexistence of at least two types of lactate consumers, Anaerobutyricum and Copro coccus_A / Frisingicoccus, despite supposedly strong competition for lactate. These lactate consumers differ in the metabolic pathway they encode, with the former producing butyrate and the latter propionate24. A strong guild structure possibly applies within the lactate-to-propionate consumers (Coprococcus_A and Frisingicoccus). The inventors thus propose that niches—and thus the functional guilds that associate with them—should be defined taking into account both inputs and outputs, and the physicochemical parameters that modulate these inputs and outputs. Finally, the variety of different niches at each trophic level decreases from top to bottom. The combination of all three aspects leads to the predictions of different amounts of taxonomic diversity at each trophic level. First, at the complex degrader level, overall taxonomic diversity is high, but this is driven by the diversity in substrates. Second, at the simple degrader level, taxonomic diversity is also high, but here this is driven by the competition for a small variety of simple sugars. Third, at the secondary consumer level, taxonomic diversity is low, driven by the combination of very low niche diversity and low energetic yields. Taken together, this implies opposing forces that drive gut microbiome structure and function. Energy flows ‘top- down’, determined first by the available substrates and their corresponding de-graders. Conversely, context flows ‘bottom-up’, with the guild composition at the secondary degrader level ultimately determining the metabolic fate of the degraded carbon sources and thus the overall community output. The inventor’s approach complements other methods to describe how gut microbiome function is structured. Importantly, it provides much needed quantitative biological data to inform computational models. As a consequence of measuring the biological phenotype directly using low-throughput microbiological experiments, instead of high-throughput genomic approaches, the study is limited in terms of the number of different microbiomes the inventors screened. Nevertheless, by choosing these along the enterotype gradient, the inventors managed to obtain a representative sample of the described microbiome diversity. The competitive growth assay also imposes a strong bottleneck in terms of initial dilution of the fecal sample which the inventors account for using a careful probabilistic model. By design, this puts a focus on those taxa that have sufficient abundance to drive the metabolic conversions in the gut. Despite the small number of fecal microbiota and initial bottleneck, the inventors were able to make predictions that were validated in a nutritional intervention study. The inventors managed to capture most of the in vivo microbiome response. This is possible because of the high degree of conservation at the complex degrader level. The inventors therefore expect their approach to also be accurate in the prediction of the microbiome response to other dietary fibers or nutritional supplements, allowing for fiber design and pre-screening prior to costly intervention studies and coming a step closer towards personalized nutrition. Overall, the inventors have put forward an approach to generate a structure-function map for gut microbiomes that is based on context-aware phenotypic data. This has the important advantage over genomic or statistical methods by directly measuring what functions are performed by a complex microbiome and identifying putative bacteria that are phenotypically associated with this function. Having such a map on hand will contribute to a better understanding of microbiome function and dysbiosis, thus enabling better targeted functional interventions. Example 7: Medical applications To identify diseases that are targets for a co-administration of eligible strains and a specific substrate according to the present invention, the inventors compared the relative abundance of bacterial genera in fecal samples from patients across different diseases and healthy individuals. The inventors made use of different publicly available datasets of either shotgun metagenomic data from the curatedMetagenomicData repository (see for example Pasolli et al., Nature Methods, volume 14, pages 1023-1024 (2017)), or 16S amplicon data from a cohort of IBD pateints from Ireland (Cork-Irish) and Canada (Cork-Canadian) (https: / / 10.1136 / gutjnl-2020-321106), a cohort of patients undergoing hematopoeitic stem cell transplantation (MSK; https: / / www.nature.com / articles / s41597-021-00860-8), a cohort of patients with acute leukemia (UMN-AML; https: / / doi.org / 10.1182 / bloodadvances.2021004973), a cohort of patients with multiple sclerosis (iMSMS; https: / / doi.org / 10.1016 / j.cell.2022.08.021) and a cohort of healthy fecal donors (PB). For shotgun data from the curatedMetagenomicData collection, the inventors estimated differences in abundance between disease and healthy microbiomes by performing t-tests between the relative abundance of a genus in patients and the relative abundance of healthy individuals in the corresponding same cohort. In each case, the x-axis represents the estimated difference in relative abundance in patients compared to healthy subjects and the y-axis shows the relevant cohort in the collection. For amplicon data from the other cohorts, the inventors fit a linear mixed model with disease as a fixed effect and cohort as a random effect for each genus of interest. The y-axis represents the relative abundance of the specific genus in each cohort. The following Table 1 links bacterial genera to the relevant Figures where the abundance of a specific genus in a patient cohort in comparison to a healthy individual cohort is displayed. HSCT=hematopoietic stem cell transplantation; AML = acute myeloid leukemia; CRC = colorectal cancer, IGT = impaired glucose tolerance; T1D = type 1 diabetes; T2D = type 2 diabetes; CDI = clostridioides difficile infection; IBD = Inflammatory bowel disease; ACVD = atherosclerotic cardiovasular disease. Table 1. Genus CuratedMetagenomicData 16S amplicon data Relevance for disease Acetatifactor Figure 7 HSCT, AML Acutalibacter Figure 8 adenoma, CRC, migraine, asthma, carcinoma Agathobacter Figure 9 HSCT, AML Akkermansia Figure 10 CRC, Parkinson’s , carcinoma Anaerostipes Figure 11 IBD, IGT, hypertension Bacteroides Figure 12A Figure 12B Diarrhea, CDI, HSCT Blautia_A Figure 13 IBD, CRC, T1D, T2D, IGT CAG-41 Figure 14 AML Clostridium_A Figure 15 CRC, carcinoma, IGT / T2D Coprococcus Figure 16 AML, HSCT Eisenbergiella Figure 17 ACVD, T1D, IBD, T2D, asthma,, CRC Eubacterium_G Figure 18B AML Fusicatenibacter Figure 19 HSCT, AML Lachnospira Figure 20A Figure 20B IBD, HSCT, AML Parabacteroides Figure 21A Figure 21B CRC, HSCT Roseburia Figure 22 HSCT Ruminococcus_A Figure 23 AML Ruminococcus_D Figure 24A Figure 24B IBD, IGT, T1D, T2D,. AML Ruminococcus_E Figure 25A Figure 25B ACVD, cancer, HSCT, AML TF01-11 Figure 26 HSCT, AML UMGS1375 Figure 27 AML Figure 7: Bacterial strains of the genus Acetatifactor are underrepresented in cohorts of patients undergoing hematopoietic stem cell transplantation (HSCT) and at risk of graft versus host disease (GvHD) and in patients with acute myeloid leukemia (AML), implying a specific association of this genus with HSCT and AML. Figure 8: Bacterial strains of the genus Acutalibacter are underrepresented in cohorts of patients with adenoma, CRC, migraine, asthma and carcinoma, implying a specific association of this genus with adenoma, CRC, migraine, asthma and carcinoma. Figure 9: Bacterial strains of the genus Agathobacter are underrepresented in cohorts of patients undergoing hematopoietic stem cell transplantation (HSCT) and at risk of graft versus host disease (GvHD) and in patients with acute myeloid leukemia (AML), implying a specific association of this genus with HSCT and AML. Figure 10: Bacterial strains of the genus Akkermansia are underrepresented in relevant patient cohorts (CRC, Parkinson’s , carcinoma). This suggests a specific association of this genus with CRC, Parkinson's disease, and carcinoma. Figure 11: Bacterial strains of the genus Anaerostipes are underrepresented in relevant patient cohorts (IBD, IGT, hypertension). This suggests a specific association of this genus with IBD, IGT, and hypertension. Figure 12A, 12B: Bacterial strains of the genus Bacteroides are underrepresented in relevant patient cohorts (Diarrhea, CDI, HSCT). This suggests a specific association of this genus with diarrhea, CDI, and HSCT. Figure 13: Bacterial strains of the genus Blautia_A are underrepresented in relevant patient cohorts (IBD, CRC, T1D, T2D, and IGT). This suggests a specific association of this genus with IBD, CRC, T1D, T2D, and IGT. Figure 14: Bacterial strains of the genus CAG-41 are underrepresented in relevant patient cohorts (AML). This suggests a specific association of this genus with AML. Figure 15: Bacterial strains of the genus Clostridium_A are underrepresented in relevant patient cohorts (CRC, carcinoma, and IGT / T2D). This suggests a specific association of this genus with CRC, carcinoma, and IGT / T2D. Figure 16: Bacterial strains of the genus Coprococcus are underrepresented in relevant patient cohorts (AML and HSCT). This suggests a specific association of this genus with AML and HSCT. Figure 17: Bacterial strains of the genus Eisenbergiella are underrepresented in relevant patient cohorts (ACVD, T1D, IBD, T2D, asthma, and CRC). This suggests a specific association of this genus with ACVD, T1D, IBD, T2D, asthma, and CRC. Figure 18B: Bacterial strains of the genus Eubacterium_G are underrepresented in relevant patient cohorts (AML). This suggests a specific association of this genus with AML. Figure 19: Bacterial strains of the genus Fusicatenibacter are underrepresented in relevant patient cohorts (HSCT and AML). This suggests a specific association of this genus with HSCT and AML. Figure 20A, 20B: Bacterial strains of the genus Lachnospira are underrepresented in cohorts of patients undergoing hematopoietic stem cell transplantation (HSCT) and at risk of graft versus host disease (GvHD), in patients with IBD and in patients with AML. Patients with multiple sclerosis (MS) had Lachnospira abundances that did not differ from healthy subjects, implying a specific association with HSCT, AML, and IBD. Patients suffering from these conditions showed significantly lower abundance of Lachnospira genus bacteria than the healthy participants. Figure 21A, 21B: Bacterial strains of the genus Parabacteroides are underrepresented in relevant patient cohorts (CRC, HSCT). This suggests a specific association of this genus with CRC and HSCT. Figure 22: Bacterial strains of the genus Roseburia are underrepresented in cohorts of patients undergoing hematopoietic stem cell transplantation (HSCT) and at risk of graft versus host disease (GvHD). This suggests a specific association of this genus with HSCT. Figure 23: Bacterial strains of the genus Ruminococcus_A are underrepresented in relevant patient cohorts (AML). This suggests a specific association of this genus with AML. Figure 24A, 24B:Bacterial strains of the genus Ruminococcus_D are underrepresented in relevant patient cohorts (IBD, IGT, T1D, T2D, and AML). This suggests a specific association of this genus with IBD, IGT, T1D, T2D, and AML. Figure 25A, 25B: Bacterial strains of the genus Ruminococcus_E are underrepresented in relevant patient cohorts (ACVD, carcinoma, hypertension, HSCT, and AML). This suggests a specific association of this genus with ACVD, carcinoma, hypertension, HSCT, and AML. Figure 26: Bacterial strains of the genus TF01-11 are underrepresented in cohorts of patients undergoing hematopoietic stem cell transplantation (HSCT) and at risk of graft versus host disease (GvHD) and in patients with acute myeloid leukemia (AML), implying a specific association of this genus with HSCT and AML. Figure 27: Bacterial strains of the genus UMGS1375 are underrepresented in cohorts of pateints with acute myeloid leukemia (AML), implying a specific association of this genus with AML. Example 8: Translatability into mouse model (i) Engraftment of Lachnospira species (Lachnospira eligens) in mice (single strain): The objective is to demonstrate that the co-administration of pectin (PE) together with Lachnospira eligens (L. eligens) to germ- free mice leads to faster colonization and / or higher abundances in feces and the cecum. To this end, overnight cultures (24h in YCFA growth medium) of L. eligens are administered via a single oral gavage (200 µl) to two groups of 8 wild-type C57BL / 6J germ-free mice each: one group on a standard diet that is supplemented by pectin (pectin group), and the other on a standard diet without pectin supplementation (control group). Feces are collected twice daily from individual mice for the first three days, and once daily for up to 10 days. After 10 days, the mice are euthanized, and their cecum content is collected. The abundance of L. eligens is quantified with qPCR. First, the abundance in the cecum content is compared between the two groups, where the mean cecal abundance in the control group is interpreted as the ‘reference abundance’. A cecal abundance that is higher in the pectin group compared to the control group is interpreted as a supportive effect of pectin on Lachnospira colonization. Second, the ‘colonization time’ required to reach 90% of the ‘reference abundance’ is determined for each mouse based on the abundances in the feces. A shorter colonization time in the pectin group compared to the control group is interpreted as a supportive effect of pectin on Lachnospira colonization. (ii) Engraftment of Lachnospira species (Lachnospira eligens) in mice as a part of a consortium: The objective of this experiment is to demonstrate that the co-administration of pectin (PE) together with a bacterial consortium comprising Lachnospira eligens (L. eligens) to germ-free mice leads to faster colonization and / or higher abundances in feces and the cecum. The consortium consists of L. eligens and 8 other strains (B. adolescentis, R. bromii, B. xylanisolvens, L. Rhamnosus, B. hydrogenotrophica, A. caccae, P. faecium, A. rectalis) that are co-cultivated in continuous culture in a pH-controlled stirred-tank bioreactor at 37°C. A fresh sample (200µl) of the consortium from the bioreactor is administered to two groups of 8 wild-type C57BL / 6J germ-free mice by a single oral gavage: one group on a standard diet supplemented with pectin (PE group) and the other on a standard diet without supplementation. Feces are collected twice daily from individual mice for the first three days, and once daily for up to 10 days. After 10 days, the mice are euthanized, and their cecum content is collected. The total bacterial load in feces and the cecum content is determined by qPCR with universal 16S primers. The relative abundances of each of the strains is determined by 16S amplicon metagenomic sequencing. The absolute abundance of individual bacteria including L. eligens is estimated by multiplying the total bacterial load by the relative abundance of the respective strain. First, the abundance in the cecum content is compared between the two groups, where the mean cecal abundance in the control group is interpreted as the ‘reference abundance’. A cecal abundance that is higher in the pectin group compared to the control group is interpreted as a supportive effect of pectin on Lachnospira colonization. Second, the ‘colonization time’ required to reach 90% of the ‘reference abundance’ is determined for each mouse based on the abundances in the feces. A shorter colonization time in the pectin group compared to the control group will be interpreted as a supportive effect of pectin on Lachnospira colonization. Material and Methods Collection of feces. Fresh fecal samples were donated from eight healthy individuals with no history of antibiotic use, intestinal infections, or severe diarrhea during the three months prior to making the donation. The donors did not take immunosuppressive drugs, blood thinners, or medication affecting the bowel passage or digestion. Fecal samples were anaerobically transported in an airtight container together with an Oxoid™ AnaeroGen™ 2.5 liter sachet (Thermo Fisher Diagnostics AG, Pratteln, Switzerland) and processed within three hours after defecation. Stool consistency was evaluated optically according to the Bristol Stool Scale (Lewis and Heaton 1997) and samples within the defined range of a healthy stool, notably with a score between 3-5, were accepted. Culture media and anaerobic dilution solution. Culture media were based on a common basal medium and supplemented with nine distinct growth substrates (Figure 1a). All medium ingredients except sodium bicarbonate and L-cysteine HCl were dissolved in an Erlenmeyer flask and the pH was adjusted to 7 by titrating 5 mM sodium hydroxide. The media were boiled for 15 min for major removal of oxygen, under constant moderate stirring, and using a Liebig condenser to prevent vaporization of ingredients. After boiling, the media were constantly flushed with CO2. Sodium bicarbonate and L-cysteine hydrochloride monohydrate were added when the media cooled down to 55° C for further reduction of residual oxygen for 10 min. Aliquots of 8 ml of medium were filled into Hungate tubes under constant flushing with CO2, and Hungate tubes were sealed with butyl rubber stoppers and screw caps (Millan SA, Geneva, Switzerland). The media were sterilized by autoclaving and subsequently stored at room temperature. Anaerobic dilution solution for fecal samples was prepared following the same procedure as for the culture media, except that aliquots of 9 ml were filled into Hungate tubes to facilitate serial dilutions. Feces processing and dilutions. For processing, the fecal samples were transferred into a Coy anaerobic chamber (Coy Laboratories, Ann Arbor, MI, USA) with an atmosphere of 10% CO2, 5% H2, and 85% N2. The inventors prepared a 1:10 dilution with one gram of fecal sample that was measured with a sterile plastic spoon (VWR International, Dietikon, Switzerland) and subsequently suspended in 9 ml of anaerobic dilution solution. The inventors transferred 1 ml of the 1:10 dilution into 9 ml of anaerobic dilution to obtain a 1:100 dilution. The inventors then transferred 1 mL of the 1:100 dilution into a sterile Hungate tube containing 9 mL of anaerobic dilution solution. The inventors performed subsequent serial dilutions in steps of 10 down to 10-11 outside of the anaerobic chamber under sterile, anaerobic conditions using the Hungate technique (Bryant 1972). In vitro enrichments. Anaerobic in vitro enrichments were performed in Hungate tubes sealed with butyl rubber stoppers and screw caps (Millan SA, Geneva, Switzerland). For each fermentation, 0.3 ml of the 10-8 fecal sample dilution was inoculated into 8 ml (~ 10-9 dilution) of cultivation medium under sterile and anaerobic conditions using the Hungate technique (Bryant 1972). All cultures were incubated at 37 °C. After 48 h of incubation, the inventors measured optical density at a wavelength of 600 nm (OD600) directly in the Hungate tubes with a WPA CO 8000 Cell Density Meter (Biochrom Ltd, Cambridge, England). Microbial metabolite analysis. Metabolite concentrations of acetate, propionate, butyrate, lactate, succinate, formate, and ethanol were measured by HPLC analysis. Samples were prepared from 1 ml of bacterial culture centrifuged at 14’000 g for 10 min at 4 °C. The supernatant was filtered into 2 ml short thread vials with crimp caps (VWR International GmbH, Schlieren, Switzerland) using non-sterile 0.2 µm regenerated cellulose membrane filters (Phenomenex Inc., Aschaffenburg, Germany). A volume of 40 µl of sample was injected into the HPLC with a flow rate of 0.6 ml / min at a constant column temperature of 80 °C and using a mixture of H2SO4 (10 mM) and Na-azide (0.05 g / L) as eluent. Analyses were performed with a Hitachi Chromaster 5450 RI-Detector (VWR International GmbH, Schlieren, Switzerland) using a Rezex ROA-Organic Acid (4 %) precolumn connected to a Rezex ROA-Organic Acid (8 %) column, equipped with a Security Guard Carbo-H cartridge (4 × 3.0 mm). Metabolite concentrations were determined using external standards (all purchased from Sigma-Aldrich, Buchs, Switzerland) via comparison of the retention times. Peaks were integrated using the EZChromElite software (Version V3.3.2.SP2, Hitachi High Tech Science Corporation). DNA extraction. For fecal samples, the inventors extracted total genomic DNA from 200 mg of each sample. For fermentations, the inventors centrifuged 1 ml of bacterial cultures at 14’000 g and 4 °C for 10 mins. For both sample types, the inventors used the FastDNA® SPIN Kit for Soil (MP Biomedicals, Illkirch Cedex, France) according to the manufacturer’s instructions. The inventors quantified the total DNA concentration using the Qubit® dsDNA HS Assay kit (Thermo Fisher Scientific, Pratteln, Switzerland). Amplicon sequence variants and taxonomic assignment. The inventors performed amplicon sequencing of the 16S rRNA V3-V4 region on the MiSeq platform (Illumina, CA, USA) using the primer combination 341F (5"- CCTACGGGNBGCASCAG-3) and 806bR (5"- GGACTACNVGGGTWTCTAAT-3"). Library preparation and sequencing was performed by StarSEQ GmbH (Mainz, Germany) with 25% PhiX to balance the composition of bases. Amplicon Sequence Variants (ASVs) were inferred using Dada2 v1.18.0 (Callahan et al.2015) with read length filtering set to (250, 210), maxEE set to (4,5), inference done in “pseudo pool” mode. Read pairs were merged with minimum overlap of 20, and bimeras were removed using the “consensus” method. Taxonomic annotation was performed with the assignTaxonomy function from Dada2 using GTDB r95 taxonomic database Dada2 (Parks et al.2021) prepared for Dada2. Quantification of total viable cells in feces. The inventors estimated the total number of viable cells in feces by MPN enumeration in liquid culture and using strict anaerobic Hungate techniques. To this end, for each fecal sample the inventors inoculated 0.3 ml of the 10-9, 10-10, and 10-11 dilutions into 8 ml of M2GSC growth medium in triplicates. The inventors categorized positive growth in a tube as an OD600 > 0.5. The inventors performed a Bayesian estimation of the concentration of viable cells, λ, in the fecal samples by fitting a binomial model to the number of tubes for which the inventors observed growth. The inventors used a Gamma prior on λ with α = 1 and β = 0.01 and sampled from the posterior with RStan. All samples had viable cell numbers within a range of 1010-1012 cells per gram of feces, as expected for healthy stool (Franks et al. 1998). Estimation of cell concentrations from total DNA. The inventors fit a statistical model to predict cell densities [cells / ml] from the concentration of total extracted DNA [ng / ml]. To this end the inventors used data from pilot enrichments that were performed on the same panel of carbon sources except for AG and YE using the same methodology except that substrates were added at a concentration of 6 g / l. The remainder of the protocol was identical to what is described here. For each of the enrichment cultures, the inventors measured absolute abundances using two methods: (i) the concentration of total extracted DNA using the Qubit® dsDNA HS Assay kit; (ii) total bacterial cell concentrations with qPCR using universal 16S primers. The inventors then fit a linear model relating the measured log DNA concentration, x, to the measured log cell concentration, y. Because both x and y are measured quantities of a true value x0 and y0 for x and y, respectively, the inventors used a Bayesian approach where x ~ N(x0, ^^^^x), y ~ N(y0, ^^^^y), and y0 = a + b x0. The inventors coded this model in Stan with priors ^^^^x, ^^^^y ~ ^^^^(0.1,0.1), a ~ N(0,5), b ~ N(0,1), and x0 ~ N(0,10). Posterior samples (n = 4000) were generated with RStan. Sampling from this full model resulted in a strong anti-correlation between a and b, and a mean posterior estimate of b = 0.98 very close to 1. Because the inventors expect the DNA concentration and cell concentration to scale proportionally on a linear scale (b = 1), the inventors repeated the fit with b fixed to 1. This resolved the posterior parameter correlations and hence the inventors used this simplified to convert DNA concentration to cell concentrations in this setup. Estimation of total carbon extraction and total bacterial growth. The inventors performed Bayesian estimation of the mean total carbon extracted from the primary substrates. The inventors first computed the total concentration of carbon in the samples by multiplying the individual measured metabolite concentrations by the respective carbon count of the molecule and summing over all measured metabolites. The inventors then fit a model with a joint baseline, µ0, across all growth conditions including mM2 without added substrate, a mean effect, µs, for each substrate, and a donor-substrate specific deviation, νd,s. This has the advantage of using all of the data to estimate the contribution from the baseline (mM2) and is more conservative in terms of uncertainty than using growth on mM2 alone. The inventors used very weakly normally distributed priors for µ ~ Normal(30,50) and µs ~ Normal(50,30) that were roughly centered around the observed concentrations from the pilot experiment to improve seeding of the MCMC chains. The inventors performed the Bayesian equivalent of LASSO regularization using Laplace priors for the νd,s with a hyperparameter σν for the variance, νd,s ~ Laplace(0, σν) and σν ~ InvGamma(0.1, 0.1). The inventors modeled the residual error across replicates as ε ~ Normal(0, σε), where σε ~ InvGamma(0.1,0.1). The inventors coded the model in the Stan language and performed posterior sampling using RStan. The inventors used the same model to estimate the total amount of bacterial growth, just using the estimated log10 cell concentrations instead of the total carbon. Computation of relative enrichment. The inventors first computed the expected relative abundance in a sample, xi = (ni+ji) / N, where ni is the number of sequencing reads, ji = 1 if the taxon was observed in any of the enrichments inoculated with that specific fecal sample and ji = 0 otherwise, and N is the total number of sequencing reads in the sample. The Bayesian interpretation of the pseudo count ji = 1 corresponds to computing the posterior mean under the assumption of a multinomial sampling model with a flat Dirichlet prior for those genera that were observed at least once in at least one sample. The inventors computed the absolute abundances, Xi, by multiplying xi with the estimated cell concentrations for each sample. To account for the potential loss of a taxon, i, during the dilution at the inoculation step, the inventors computed the probability that a taxon is inoculated with at least one cell in a culture. The inventors used the posterior samples of the fecal cell densities, λ, using the MPN method, and assumed that the total number of cells, M, that are retained in the inoculum that is diluted ϑ-fold is sampled from a Poisson distribution with rate λϑ. The number of cells of each taxon, mi, that make it into the inoculum is then sampled with M draws from a multinomial distribution with probabilities equal to the relative abundance in the fecal sample, zi, where zi ~ Dirichlet(n+j) equivalent to the computation of xi above. Using the posterior samples of mi, the inventors compute the probability of loss to dilution, p0,i, as the fraction of posterior draws that give mi = 0. Furthermore, the inventors define p1,i as the relative abundance of taxon i in the inoculum sample conditioned on not having been lost. The inventors then computed a weighted average for the estimated relative and absolute abundances over the triplicates that accounts for potential loss to dilution in the inoculum, yi = (xi1 wi1 + xi2 wi2 + xi3 wi3) / 3, where wik = 1 if the taxon was observed in the k-th replicate of the enrichment culture, and wik = 1– p0(i) if it was not observed. The inventors then computed the relative enrichment of a taxon in a specific condition as the change in log10 relative abundance from a reference composition, Ei = log10(xi) – log10(xi(ref)), where the reference was typically the diluted fecal composition, p1, or the enriched composition, y, in mM2. The inventors also computed the absolute enrichment, Ai = log2(Xi) – log2(Xi(ref)), and the biomass increase Bi = Xi – Xi(ref). Nutritional supplementation study with NUTRIOSE®. The study protocol and its annexes were submitted to the CPP II Ile-de-France Ethics Committee (Saints Pères) on April 18, 2012. The project was analyzed on May 3rd, 2012 and additional information was requested. The complementary file was analyzed by the ethics committee on May 22, 2012 and final positive opinion was given on May 24, 2012. The AFSSAPS identifier (ID RCB) is 2012-A00061-40. The protocol was registered on ClinicalTrials.gov (NCT01897649). The study was a monocentric, randomized, controlled and double-blind study, conducted with two parallel groups: Control group (or comparator) and Test group. The intervention phase of the study lasted 35 days from the date of inclusion in the study. Sixty subjects were recruited during the pre-selection visit and included in the protocol during the inclusion visit. Subjects were randomized in two groups (thirty subjects per group). Each subject consumed the tested product (15g NUTRIOSE® FB06) or the comparator (GLUCIDEX® 21) during 28 days from D1 to D28 (see study design flowchart, Figure 1). Subjects were asked to give a stool sample at day D-7 (i.e. one week before D1, at the inclusion visit), 14 days after the beginning of product consumption D14 (i.e. at the follow-up visit), and at day D29 (i.e. at the study end visit). Subjects were asked to record food intake for three non-consecutive days including 2 weekdays and one weekend day the week before D1, D15 and D28. NUTRIOSE FB06 is a soluble dietary fiber produced from wheat starch, manufactured and marketed by Roquette Frères Company. NUTRIOSE® was provided in the form of a white powder, odorless, tasteless. The product was packaged in aluminum sealed bags. Each bag contained 15g NUTRIOSE® FB06. GLUCIDEX® 21 is dried glucose syrup derived from corn starch. It is composed of 3% glucose, 7% maltose and 90% of glucose polymers with polymerization degree ≥ 3. GLUCIDEX® 21 is in the form of a white powder with a slightly sweet flavor. Each subject consumed the content of one bag (NUTRIOSE® or comparator product) per day during 28 days. Stool samples were collected at D-7, D14 and D29. Defecation takes place at home on the morning of the medical visit or at the Research Centre. A thermal protector device allowing temperature maintenance at 4 °C for 12 hours was provided to volunteer for stool transportation from home to hospital. Stools were kept at 4 °C at the Research Centre until sampling and frozen at -80 °C. The transport of frozen stool samples at - 80 °C to the laboratory in charge of microbiological analysis was performed at -80 °C using an adequate volume of dry ice. A 25 mg lyophilised sample of faeces was used for extraction of DNA using a commercial kit (QIAamp DNA stool kit; Qiagen). Total bacterial DNA was extracted using a commercial kit (QIAmp DNA Stool Handbook Kit; Qiagen).16S amplicon sequencing of the V3-V4 region was performed on Illumina MiSeq (2x 300bp) at DNAVision (Gosselies, Belgium). ASVs were inferred using the same pipeline as described for the enrichments.

Claims

CLAIMS 1- A combination therapy comprising (i) at least one bacterial strain and (ii) at least one dietary fibre or carbohydrate source, wherein said combination therapy comprises: (a) at least one bacterial strain selected from the genera Lachnospira, UMGS1375, CAG-41, CAG-274 and UMGS1441, and (b) pectin (PE); (a) at least one bacterial strain selected from the genera Ruminococcus_D, Lachnospira, CAG-41, TF01-11, UMGS1441, Ruminiclostridium_E, Agathobacter, Acetatifactor and Kineothrix; and (b) pea fibre (PF); (a) at least one bacterial strain selected from the genera UMGS1375, Lachnospira, Olsenella_E, Murimonas, and Acetatifactor and (b) arabinogalactan (AG); (a) at least one bacterial strain selected from the genera UMGS1375, Acutalibacter, Parabacteroides, Fusicatenibacter, Clostridium_A, Eisenbergiella, Agathobacter, Murimonas and Ruminococcus_A; and (b) resistant dextrin (RD); (a) at least one bacterial strain selected from the genera Blautia_A, Agathobacter, Bifidobacterium, Fusicatenibacter, Acetatifactor, Murimonas; and (b) xylan (XY); (a) at least one bacterial strain selected from the genera UMGS1375, Akkermansia, Ruminococcus_E, GCA- 900066135, Eubacterium_G, Agathobacter, Barnesiella, Mediterraneibacter and CAG-45; and (b) mucin (MU); (a) at least one bacterial strain selected from the genera Anaerostipes, Parabacteroides, Phascolarctobacterium_A, Bacteroides and Phascolarctobacterium; and (b) yeast extract (YE); and / or (a) at least one bacterial strain selected from the genera Agathobacter, Roseburia, Coprococcus, CAG-45, Acetatifactor and Ruminococcus_E; and (b) soluble starch (SS). 2- The combination therapy of claim 1, said combination therapy comprising: (a) at least one bacterial strain selected from the group consisting of Acutalibacter timonensis, Acutalibacter sp003612555, Parabacteroides distasonis, Parabacteroides merdae, Fusicatenibacter saccharivorans, Clostridium_A leptum, Eisenbergiella sp900066775, Eisenbergiella massiliensis, Eisenbergiella tayi, UMGS1375 sp900066615, Agathobacter rectalis, Agathobacter faecis, Murimonas intestini, Ruminococcus_A sp000437095, Ruminococcus_A sp003011855; and (b) resistant dextrin (RD); (a) at least one bacterial strain selected from the group consisting of CAG-41 sp900066215, UMGS1441 sp900551755, Lachnospira eligens, Lachnospira rogosae, Lachnospira sp003451515, Lachnospira sp003537285, CAG-274 sp900545305 and UMGS1375 sp900066615 ; and (b) pectin (PE); (a) at least one bacterial strain selected from the group consisting of CAG-41 sp900066215, TF01-11 sp001414325, UMGS1441 sp900551755, Lachnospira rogosae, Lachnospira sp003537285, Ruminiclostridium_E siraeum, Agathobacter faecis, Agathobacter rectalis, Acetatifactor sp900066365, Ruminococcus_D bicirculans, Ruminococcus_D sp900604945, Kineothrix alysoides and (b) pea fibre (PF);(a) at least one bacterial strain selected from the group consisting of UMGS1375 sp900066615, Olsenella_E sp003609875, Murimonas intestini, Acetatifactor sp900066565, Lachnospira eligens and (b) (b) arabinogalactan (AG); (a) at least one bacterial strain selected from the group consisting of UMGS1375 sp900066615, Akkermansia muciniphila, Ruminococcus_E bromii, GCA-900066135 sp900066135, Eubacterium_G ventriosum, Eubacterium_G sp000434315, Agathobacter faecis, Agathobacter rectalis, Barnesiella intestinihominis, Mediterraneibacter faecis, Mediterraneibacter torques, CAG-45 sp900066395 and (b) mucin (MU); (a) at least one bacterial strain selected from the group consisting of Anaerostipes sp90006670, Parabacteroides merdae, Phascolarctobacterium_A succinatutens, Bacteroides faecichinchillae, Bacteroides ovatus, Phascolarctobacterium faecium and (b) yeast extract (YE); (a) at least one bacterial strain selected from the group consisting of Agathobacter rectalis, Agathobacter faecis, Roseburia intestinalis, Roseburia sp001940165, Coprococcus eutactus, CAG-45 sp900066395, Acetatifactor sp900066365, Ruminococcus_E sp003438075 and (b) soluble starch (SS); and / or (a) at least one bacterial strain is selected from the group consisting of Agathobacter rectalis, Blautia_A sp003471165, Blautia_A sp003471165, Bifidobacterium adolescentis, Fusicatenibacter saccharivorans, Acetatifactor sp900066565, Murimonas intestini and (b) xylan (XY). 3- The combination therapy according claim 1 or 2, wherein the at least one bacterial strain is comprised in a bacterial consortium comprising no more than 15 different bacterial strains, preferably between 5 to 15 different bacterial strains, more preferably between 6 and 10 different bacterial strains. 4- The combination therapy according to claim 3, wherein the bacterial consortium comprises: - one or several bacterial strain(s) able to convert primary substrates into lactate (A4); - one or several bacterial strain(s) able to convert lactate into butyrate (B3); and / or - one or several bacterial strain(s) able to convert lactate into propionate (B4). 5- The combination therapy according claim 4, wherein: - the one or several bacterial strain(s) able to convert primary substrates into lactate (A4) transform at least 30%, at least 50%, more preferably at least 60% of the total carbon transformed into the combined metabolites formate (FO), lactate (LT), succinate (SU), acetate (AA), butyrate (BA), propionate (PA) and Ethanol (Et) into lactate when grown for 48 hours in single culture on standard medium;- the one or several bacterial strain(s) able to convert lactate into butyrate (B3) degrade at least 20% of lactate in medium and transform at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Et into butyrate when grown for 48 hours in single culture on standard medium supplemented with lactate; and / or - the one or several bacterial strain(s) able to convert lactate into propionate (B4) degrade at least 20% of lactate in medium and transform at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Et into propionate when grown for 48 hours in single culture on standard medium supplemented with lactate. 6- The combination therapy according to claim 4 or 5, wherein - the one or several bacterial strain(s) able to convert primary substrates into lactate (A4) are selected from the genera Agathobacter, Bacteroides, Bariatricus, Bifidobacterium, Collinsella, Enterococcus, Lacticaseibacillus / Lactobacillus, Longicatena, Merdisoma, Peptostreptococcus, Roseburia, Streptococcus and Sutterella; preferably from the genera Agathobacter, Bacteroides, Bariatricus, Collinsella, Enterococcus, Lacticaseibacillus / Lactobacillus, Peptostreptococcus, Streptococcus, and Sutterella; more preferably from the genera Agathobacter, Bacteroides, Bariatricus, Collinsella, Enterococcus, Lacticaseibacillus / Lactobacillus, Streptococcus, and Sutterella; - the one or several bacterial strain(s) able to convert lactate into butyrate (B3) are selected from the genera Anaerobutyricum, Anaerostipes and Eubacterium; preferably from the genera Anaerobutyricum and Anaerostipes; and / or - the one or several bacterial strain(s) able to convert lactate into propionate (B4) are selected from the genera Anaerotignum, Clostridium, Coprococcus_A, Frisingococcus and Veillonella; preferably from the genera Anaerotignum genus, Coprococcus_A, Frisingococcus and Veillonella. 7- The combination therapy according to any one of claims 3-6, wherein the bacterial consortium comprises: - one or several bacterial strain(s) able to convert primary substrates into formate (A1); - one or several bacterial strain(s) able to convert primary substrates into acetate (A2); - one or several bacterial strain(s) able to convert formate into acetate (B1); and / or - one or several bacterial strain(s) able to convert acetate into butyrate (B2).8- The combination therapy according to claim 7, wherein: - the one or several bacterial strain(s) able to convert primary substrates into formate (A1) transform at least 20%, at least 25%, more preferably at least 30% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Et into formate when grown for 48 hours in single culture on standard medium; - the one or several bacterial strain(s) able to convert primary substrates into acetate (A2) transform at least 30%, at least 50%, more preferably at least 60% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Et into acetate when grown for 48 hours in single culture on standard medium; - the one or several bacterial strain(s) able to convert formate into acetate (B1) degrade at least 20% of formate in medium and transform at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Et into acetate when grown for 48 hours in single culture on standard medium supplemented with formate; and / or - the one or several bacterial strain(s) able to convert acetate into butyrate (B2) degrade at least 20% of acetate in medium and transform at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Ethanol into butyrate when grown for 48 hours in single culture on standard medium or standard medium supplemented with FO, LT and / or SU. 9- The combination therapy according to claim 7 or 8, wherein: - the one or several bacterial strain(s) able to convert primary substrates into formate (A1) are selected from the genera Anaerobutyricum, Bacteroides, Blautia, Collinsella, Coprococcus, Dorea, Erysipelatoclostridium, Escherichia, Eubacterium, Faecalibacterium, Lachnospira, Longicatena, Ruminococcus, and Sellimonas; preferably from the genera Blautia, Coprococcus, Dorea, Erysipelatoclostridium, Faecalibacterium, Lachnospira and Ruminococcus; more preferably from the genera Coprococcus, Dorea, Faecalibacterium and Ruminococcus; - the one or several bacterial strain(s) able to convert primary substrates into acetate (A2) are selected from the genera Acidaminococcus, Acutalibacter, Bifidobacterium, Blautia, Clostridium, Clostridium_E, Clostridium_Q, Collinsella, Copromonas, Desulfovibrio, Dorea, Enterocloster, Escherichia, Eubacterium, Hungatella, Hungatella_A, Oliverbapstia, Peptoniphilus, Peptostreptococcus, Phocaeicola, Rhiziobiaceae genus, Ruminococcus, Sellimonas and Veillonella; preferably from the genera Bifidobacterium, Blautia, Clostridium_Q, Clostridium_E, Desulfovibrio, Dorea, Eubacterium, Oliverpabstia, and Rhiziobiaceae genus; more preferably fromthe genera Bifidobacterium, Blautia, Clostridium_E, Desulfovibrio, Dorea, Eubacterium, and Rhiziobiaceae genus; - the one or several bacterial strain(s) able to convert formate into acetate (B1) are selected from the genera Blautia and Eubacterium; and / or - the one or several bacterial strain(s) able to convert acetate into butyrate (B2) are selected from the genera Agathobacter, Anaerobutyricum, Anaerostipes, Anaerotignum, Desulfovibrio, Dysosmobacter, Faecalibacterium, Longicatena and Roseburia; preferably from the genera Agathobacter, Anaerobutyricum, Anaerostipes, Desulfovibrio, Faecalibacterium and Roseburia. 10- The combination therapy according to any one of claims 3-9, wherein the bacterial consortium comprises: - one or several bacterial strain(s) able to convert primary substrates into succinate (A6); and / or - one or several bacterial strain(s) able to convert succinate into propionate (B5). 11- The combination therapy according to claim 10, wherein: - The one or several bacterial strain(s) able to convert primary substrates into succinate (A6) transform at least 30%, at least 50%, more preferably at least 60% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Et into succinate when grown for 48 hours in single culture on standard medium; and / or - The one or several bacterial strain(s) able to convert succinate into propionate (B5) degrade at least 20% of succinate in medium and transform at least 20%, preferably at least 50%, more preferably at least 65% of the total carbon transformed into the combined metabolites FO, LT, SU, AA, PA, BA and Et into propionate when grown for 48 hours in single culture on standard medium supplemented with succinate. 12- The combination therapy according to claim 10 or 11, wherein: - The one or several bacterial strain(s) able to convert primary substrates into succinate (A6) are selected from the genera Acutalibacter, Bacteroides, Oliverbapstia, Parabacteroides, Phocaeicola and Prevotella; preferably from the genera Acutalibacter nov genus, Bacteroides, Parabacteroides, Phocaeicola and Prevotella; more preferably from the genera Acutalibacter nov genus, Bacteroides, Phocaeicola and Prevotella; and / or- The one or several bacterial strain(s) able to convert succinate into propionate (B5) are selected from the genera Dialister, Flavonifractor, Phascolarctobacterium and Veillonella; preferably from the genera Dialister, Flavonifractor, Phascolarctobacterium and Phascolarctobacterium_A. 13- The combination therapy according to any one of claims to 3-12, wherein the at least one bacterial strain is comprised in a bacteria consortium, said bacteria consortium comprising or consisting essentially of Agathobacter rectalis; Anaerostipes caccae or Anaerobutyricum hallii; Ruminococcus bromii; Bifidobacterium adolescentis; Lactobacillus rhamnosus; Blautia hydrogenotrophica; Phascolarctobacterium faecium and a bacterium selected from the group consisting of Bacteroides xylanisolvens, Prevotella copri and Acutalibacter species having at least 95% identity with SEQ ID NO:

6. 14- The combination therapy according to any one of claims 3-13, wherein the at least one bacterial strain is comprised in a bacteria consortium, said bacteria consortium comprising or consisting essentially of Agathobacter rectalis; Anaerostipes caccae; Ruminococcus bromii; Bifidobacterium adolescentis; Lactobacillus rhamnosus; Blautia hydrogenotrophica; Phascolarctobacterium faecium and a bacterium selected from the group consisting of Bacteroides xylanisolvens, Prevotella copri and Acutalibacter nov. specie. 15- The combination therapy according to any one of claims 3-14, wherein the at least one bacterial strain is comprised in a bacteria consortium, said bacteria consortium comprising or consisting essentially of: - Agathobacter rectalis; Anaerostipes caccae; Ruminococcus bromii; Bifidobacterium adolescentis; Lactobacillus rhamnosus; Blautia hydrogenotrophica; Phascolarctobacterium faecium and Bacteroides xylanisolvens; - Agathobacter rectalis; Anaerostipes Caccae; Ruminococcus bromii; Bifidobacterium adolescentis; Lactobacillus rhamnosus; Blautia hydrogenotrophica; Phascolarctobacterium faecium and Prevotella copri; or - Agathobacter rectalis; Anaerostipes Caccae; Ruminococcus bromii; Bifidobacterium adolescentis; Lactobacillus rhamnosus; Blautia hydrogenotrophica; Phascolarctobacterium faecium and Acutalibacter nov. specie having at least 95% identity with SEQ ID NO 6. 16- The combination therapy according to any one of claims 1 to 15, wherein the combination therapy comprises or consists of:a) a first pharmaceutical or nutraceutical composition comprising the at least one bacterial strain, optionally comprised in a bacteria consortium, and a second pharmaceutical or nutraceutical composition comprising the at least one dietary fibre and / or carbohydrate source; c) a pharmaceutical or nutraceutical composition comprising (I) the at least one bacterial strain, optionally comprised in a bacteria consortium, and (II) the dietary fibre and / or carbohydrate source. 17- A pharmaceutical or nutraceutical composition comprising a combination therapy according to any one of claims 1-15. 18- The pharmaceutical or nutraceutical composition of claim 17, wherein the composition comprises (I) a bacterial strain of the genus Lachnospira and (II) pea fiber, pectin and / or arabinogalactan, preferably pectin. 19- The pharmaceutical or nutraceutical composition of claim 17, wherein the composition comprises (I) a bacterial strain of the genus Ruminococcus_D and (II) pea fiber. 20- The pharmaceutical or nutraceutical composition of claim 17, wherein the composition comprises (I) a bacterial strain of the genus UMGS1375 (Hominsplanchenecus) and (II) arabinogalactan, resistant dextrin and / or pectin, preferably arabinogalactan and / or pectin. 21- The pharmaceutical or nutraceutical composition of claim 17, wherein the composition comprises (I) a bacterial strain of the genus Blautia_A and (II) xylan. 22- The pharmaceutical or nutraceutical composition of claim 17, wherein the composition comprises (I) a bacterial strain of the genus Parabacteroides and (II) resistant dextrin and optionally yeast extract. 23- The pharmaceutical or nutraceutical composition of claim 17, wherein the composition comprises (I) a bacterial strain of the genus Acutalibacter and (II) resistant dextrin. 24- The pharmaceutical or nutraceutical composition of claim 17, wherein the composition comprises (I) a bacterial strain of the genus Akkermansia and (II) mucin. 25- The pharmaceutical or nutraceutical composition of claim 17, wherein the composition comprises (I) a bacterial strain of the genus Agathobacter and (II) pea fiber, resistant dextrin, mucin and / or xylan, preferably pea fiber.26- The pharmaceutical or nutraceutical composition of claim 17, wherein the composition comprises (I) a bacterial strain of the genus CAG-41 and (II) pea fiber and / or pectin, resistant dextrin, mucin and / or xylan, preferably pea fiber 27- The pharmaceutical or nutraceutical composition of claim 17, wherein the composition comprises (I) a bacterial strain of the genus TF01-11 and (II) pea fiber. 28- The pharmaceutical or nutraceutical composition of claim 17, wherein the composition comprises (I) a bacterial strain of the genus Acetatifactor and (II) arabinogalactan, pea fiber, soluble starch and / or xylan, preferably pea fiber. 29- The pharmaceutical or nutraceutical composition of claim 17, wherein the composition comprises (I) a bacterial strain of the genus Fusicatenibacter and (II) xylan. 30- The pharmaceutical or nutraceutical composition of claim 17, wherein the composition comprises (I) a bacterial strain of the genus Anaerostipes and (II) yeast extract. 31- The pharmaceutical or nutraceutical composition of claim 17, wherein the composition comprises (I) a bacterial strain of the genus Eisenbergiella and (II) resistant dextrin. 32- The pharmaceutical or nutraceutical composition of any one of claims 17-31, wherein the composition further comprises: - propionate, acetate and / or butyrate; and / or - a pharmaceutical excipient or carrier. 33- The combination therapy according to any one of claims 1 to 16 or the pharmaceutical or nutraceutical composition according to any one of claims 17 to 32, for use as a medicament. 34- The combination therapy according to any one of claims 1 to 16 or the pharmaceutical or nutraceutical composition according to any one of claims 17 to 32, for use in the treatment of intestinal dysbiosis or of a disease or disorder caused by an intestinal dysbiosis.35- A method for treating a patient suffering from an intestinal dysbiosis or from a disease or disorder caused by an intestinal dysbiosis, comprising administering a therapeutic amount of the combined therapy according to any one of claims 1 to 16 or the pharmaceutical or nutraceutical composition according to any one of claims 17 to 32 to said patient. 36- The method of claim 35, wherein the method further comprises a step of selecting a patient as suitable for treatment with the combined therapy or the pharmaceutical or nutraceutical composition, wherein the patient is selected as suitable if the at least one bacterial strain of the combined therapy is under- represented in the intestinal microbiome of said patient. 37- Use of the combination therapy according to any one of claims 1 to 16 or the pharmaceutical or nutraceutical composition according to any one of claims 17 to 32, for the manufacture of a medicament for treating an intestinal dysbiosis or a disease or disorder caused by or related to an intestinal dysbiosis. 38- The combination therapy for use according to claim 34, the method of claim 35 or 36 or the use of claim 37, wherein the intestinal dysbiosis is caused by an antibiotic treatment. 39- The combination therapy for use according to claim 34 or 38, the method of claim 35, 36 and 36 or the use of claim 37 or 38, wherein the disease or disorder is selected from the group consisting of an inflammatory disease, an auto-immune disease, a cancer, a bacterial infection and a brain disorder, preferably in from the group consisting of infection by vancomycin resistant enterococci (VRE), infection by carbapenem resistant enterococci (CRE), post-infectious diarrhea; Parkinson’s disease (PD), herosclerotic cardiovascular disease (ACVD), coronary artery disease (CAD), hypertension inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohns’s disease (CD); impaired glucose tolerance (IGT), type 1 diabetes (T1D), type 2 diabetes (T2D), rheumatoid arthritis (RA); multiple sclerosis (MS); graft versus host disease (GvHD); gastrointestinal cancer, adenoma, colorectal cancer (CRC), acute myeloid leukemia (AML); gastritis, colitis, gastroenteritis, gingivitis, nosocomial infection and Clostridium difficile infection (CDI). 40- The combination therapy for use according to claim 34 or 38, the method of claim 35, 36 and 36 or the use of claim 37 or 38, wherein the disease or disorder is acute myeloid leukemia (AML). 41- The combination therapy for use according to claim 34 or 38, the method of claim 35, 36 and 36 or the use of claim 37 or 38, wherein the disease or disorder is inflammatory bowel disease (IBD).42- The combination therapy for use according to claim 34 or 38, the method of claim 35, 36 and 36 or the use of claim 37 or 38, wherein the disease or disorder is a complication following post-hematopoietic stem cell transplantation (HSCT), in particular graft versus host disease (GvHD). 43- The combination therapy for use according to claim 34 or 38, the method of claim 35, 36 and 36 or the use of claim 37 or 38, wherein the disease or disorder is impaired glucose tolerance (IGT) and / or type 1 diabetes (T1D). 44- The combination therapy for use according to claim 34 or 38, the method of claim 35, 36 and 36 or the use of claim 37 or 38, wherein the disease or disorder is type 2 diabetes (T2D). 45- The combination therapy for use according to claim 34 or 38, the method of claim 35, 36 and 36 or the use of claim 37 or 38, wherein the disease or disorder is cancer, in particular adenoma or colorectal cancer (CRC). 46- The combination therapy for use according to claim 34 or 38, the method of claim 35, 36 and 36 or the use of claim 37 or 38, wherein the disease or disorder is Parkinson’s disease (PD). 47- The combination therapy for use according to claim 34 or 38, the method of claim 35, 36 and 36 or the use of claim 37 or 38, wherein the disease or disorder is herosclerotic cardiovascular disease (ACVD), coronary artery disease (CAD) and / or hypertension. 48- A method for establishing a combination therapy for modulating an intestinal microbiome, comprising the steps of: a) Providing a microbiome sample distributed into at least two microbiome test samples, b) Growing a first microbiome test sample of step (a) on a reference substrate; c) Determining an absolute or relative abundance of individual microbe population in the first microbiome test sample at the end of step (b); d) Growing a second microbiome test sample of step (a) on a substrate comprising a nutritionally or therapeutically effective amount of - dietary fibers selected from the group of resistant dextrin RD, pectin PE, pea fiber PF, and arabinogalactan AG; or - a carbohydrate source selected from the group of soluble starch SS, xylan XY, yeast extract YE, mucin MU;e) Determining an absolute or relative abundance of individual microbe population in the second microbiome test sample at the end of step (d); f) Determining microbe population differentially enriched between the first and the second test sample by subtracting the absolute or relative abundance of an individual microbe population of step c) from the absolute or relative abundance of the same individual microbe population of step e); g) Attributing the enriched microbe population of step (f) to the specific substrate comprising resistant dextrin RD, pectin PE, pea fiber PF, arabinogalactan AG; soluble starch SS, xylan XY, yeast extract YE or mucin MU; h) Developing a pharmaceutical or nutritional combination for modulating an intestinal microbiome, said combination comprising (I) at least the enriched microbe population of step f); and (II) the substrate to which the enriched microbe population was attributed to in step f). 49- A combination therapy comprising or consisting of (i) at least one substrate, said substrate being at least one dietary fibre selected from the group of resistant dextrin (RD), pectin (PE), pea fibre (PF), and arabinogalactan (AG) and / or at least one carbohydrate source selected from the group of soluble starch (SS), xylan (XY), yeast extract (YE) and mucin (MU); and (ii) at least one bacterial strain, wherein the combination therapy has been developed by the method of claim 48.

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