Mixture of HMOS and bifidobacterium longum transitional microorganism

Abstract

The present invention relates to a composition comprising a Bifidobacterium longum transitional microorganism and a mixture of human milk oligosaccharides (HMOs) consisting of 2'-fucosyllactose (2'-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3- fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), wherein the Bifidobacterium longum transitional microorganism has an Average Nucleotide Identity (ANI) of at least 98% with CNCM I-5942. The invention also relates to the use of the composition for preventing, reducing the risk of and / or treating an infection in a subject. The invention also provides the composition for use in promoting a long-term immune benefit in a subject, preventing and / or reducing the risk of allergen sensitisation, preventing and / or reducing the risk of developing a respiratory condition in a subject, and / or preventing and / or reducing the risk of developing asthma in a subject.

Description

[0001] MIXTURE OF HMOS AND BIFIDOBACTERIUM LONGUM TRANSITIONAL MICROORGANISM Field of the Invention The present invention is related to a synbiotic, in particular a combination of a Bifidobacteriumlongum transitional microorganism and a mixture of human milk oligosaccharides consistingof 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose(6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), wherein the Bifidobacterium longum transitional microorganism has an Average Nucleotide Identity (ANI) of at least 98% withCNCM I-5942 and / or has at least one identifying characteristic of the B. longum transitionalstrain deposited under deposit number CNCM I-5942. The HMO mixture promotes the growthand / or survival of the Bifidobacterium longum transitional microorganism. The invention alsorelates to the synbiotic for use in preventing, reducing the risk of and / or treating an infectionin a subject. The invention also provides the synbiotic for use in promoting a long-term immunebenefit in a subject, preventing and / or reducing the risk of allergen sensitisation, preventing and / or reducing the risk of developing a respiratory condition in a subject, and / or preventingand / or reducing the risk of developing asthma in a subject.Background of the Invention A viral infection occurs when the virus proliferates inside the host’s cells and hence utilises the host's resources to promote its own multiplication. Viral infections can also interfere with the normal functioning of the host and may lead to more severe infection-related disorders, including long-term alterations in the immune system (such as inflammatory responses) andsubsequent allergic or inflammatory diseases later in life.Viral respiratory infections, such as respiratory syncytial virus (RSV), affect nearly 90% of children by the age of two (Karpinnen et al, Clin Microbiol Infect, 2016;22;208.e1-e6) and often lead to bronchiolitis, an inflammatory bronchial reaction in infants and young children (Pickles et al, J Pathol, 2015;235;266-276). In particular, severe RSV-induced bronchiolitis is a major cause of morbidity and mortality in infants globally (Nair et al, Lancet, 2010;375;9725;2545- 1555). Respiratory viruses primarily infect the airway epithelium. Higher viral loads have been associated with increased bronchiolitis severity and conversely, rapid viral load reduction in infants was associated with faster disease resolution (Pickles et al, J Pathol, 2015;235;266- 276). It is well documented that infected and necrotic epithelial cells contribute to the airway obstruction and inflammation during RSV infection (Pickles et al, J Pathol, 2015;235;266-276) and as such epithelial cell sloughing is a feature of viral bronchiolitis and associated withdisease severity (Johnson et al, Mod Pathol, 2007;20;108–119). Plasmacytoid dendritic cells(pDC) are known to be protective against pathology during RSV infection, and adaptive immune responses including CD4+ and CD8+ T cells are important in viral elimination from the respiratory tract (Openshaw et al, Annu Rev Immunol, 2017;35;501-532). If the immune defense response to such viral respiratory infections is dysregulated, inflammatory granulocytes such as neutrophils along with CD4+ and CD8+ T cell responses can also lead to immunopathology following respiratory viral infection (Newton et al, Semin Immunopathol, 2016;38;471-482). Moreover, such uncontrolled inflammatory responses can also lead to pathological airway smooth muscle remodelling, a hallmark feature of asthma reported to commence in early life (O’Reilly et al, JACI, 2013;131;1024-1032) as well as playing a central role in the pathogenesis of chronic obstructive pulmonary disease (COPD;Yan F et al, J Transl Med, 2018;16;262-270). Thus, severe viral airway infections in early liferepresent an independent risk factor for subsequent development of respiratory diseases suchas allergic airway disease (e.g. asthma; Feldman et al, Am J Respir Crit Care Med,2015;191;34-44) and chronic obstructive pulmonary disease (Savran O et al. Int J Chron Obstruct Pulmon Dis.2018; 13: 683–693) in later life.Interactions between the immune system and the microbiome play a crucial role in humanhealth. These interactions start in the prenatal period and are critical for the maturation of theimmune system in new-borns and infants. Several factors influence the composition of theinfant’s microbiota and subsequently the development of the immune system. They include maternal infection, antibiotic treatment, environmental exposure, mode of delivery, breastfeeding, and food introduction. Breastfeeding is a recognized factor that reduces severity of respiratory viral infection in infants either directly through milk bioactives (e.g. human milk oligosaccharides) or indirectly through microbiome mediated immune benefits. Human milk oligosaccharides (HMOs) have become the subject of much interest in recentyears due to their roles in numerous biological processes occurring in the human organism.Mammalian milk contains at least 130 of these complex oligosaccharides (Urashima et al, Milk Oligosaccharides, Nova Biomedical Books, New York, 2011, ISBN: 978-1-61122-831-1). Infancy, especially the first weeks, 3 months, 6 months or 12 months of life is a critical periodfor the establishment of a balanced gut microbiota. It is known that the modulation of the gutmicrobiota during infancy can prospectively have a great influence on future health status. Forexample the gut flora can have influence on the development of a strong immune system,normal growth and even on the development of obesity later in life. The gut microbiota and itsevolution during the development of the infant is, however, a fine balance between thepresence and prevalence (amount) of many populations of gut bacteria. Some gut bacteria are classified as "generally positive" while other ones are "generally negative" (or pathogenic)as to their effect on the overall health of the infant.It is known that probiotics, in particular from the Lactobacillus and Bifidobacterium genus, support protection against respiratory tract infections. The role of probiotics in viral respiratory tract infections was reviewed by Lehtoranta and co-workers (Lehtoranta et al, Eur J Clin Microbiol Infect Dis, 2014;33; 1289-1302). The weaning period has been described as a non-redundant window for immune imprinting(Cahenzli et al., Cell Host Microbe, 2013, 14(5), 559-70; Olszak et al., Science, 2012,336(6080): 489-93; Nabhani et al., Immunity, 2019, 50(5), 1276-1288). Healthy immuneimprinting promotes appropriate immune responses against environmental challenges,including infections.Due to the loss of Bifidobacterium species in the infant gut and low breast-feeding rates, thereis a need to provide infants with both HMOs and HMO-utilizing bacteria such as aBifidobacterium longum transitional microorganism and / or B. longum subsp. infantis to supporta healthy microbiome for long-term health.Additionally, there are limited means to prevent or treat viral infections. There are limitednumbers of effective antiviral drugs, for example drugs used to treat HIV and influenza, and the primary method to control viral disease is vaccination which is intended to prevent outbreaks by building immunity to a virus or a family of viruses.There remains a need to develop new strategies for preventing and / or reducing the risk of aninfection in an infant or young child, and more specifically to prevent and / or reduce the risk of viral infections (such as viral infections of the respiratory tract). Summary of the InventionThe present inventors have determined that Bifidobacterium longum subsp microorganisms(B. longum transitional) of a clade that is present in the gut microbiome of the transitionalfeeding period of mammals, particularly humans, may have beneficial effects on preventing and / or reducing the risk of developing infection. For example, the inventors have shown thatthe B. longum transitional microorganisms are capable of modulating levels of protectivecytokines (e.g. IL-6) and / or short-chain fatty acids (SCFAs); and modulating gut barrierpermeability, for example following an insult or exacerbation to gut barrier permeability. The present inventors have also surprisingly found that synbiotic intervention (aBifidobacterium longum transitional microorganism in combination with a mix of human milkoligosaccharides) in early life provides beneficial effects on preventing and / or reducing therisk of developing infection. Furthermore, the present inventors have surprisingly found that synbiotic intervention (B.infantis in combination with a mix of human milk oligosaccharides) in early life providesprotection from virus-induced bronchiolitis and promotes a sustained immune benefit into adulthood (as assessed by reduced susceptibility to pollution-enhanced allergic airway inflammation). Specifically, the present inventors have shown that synbiotic interventions resulted in a rapid resolution of virus-induced lung inflammation and appropriate lung tissue remodeling upon clearance of the virus. These findings support the use of the synbiotic in providing protection against and treatment of viral infections, in particular viral bronchiolitis, in early life and uncover functional benefits of the synbiotics to mount effective anti-viral immune responses associated with faster disease resolution. Given that viral respiratory tract infections in early life represent a major independent risk factor for subsequent asthma, recurrent wheeze and chronic obstructive pulmonary disease, dietary supplementation with the synbiotics may also prevent long-term complications associated with viral respiratory tract infections in early life. The present invention is based, at least in part, on the provision of a novel Bifidobacteriumlongum transitional microorganism strain. This B. longum transitional strain is referred toherein as NCC 5025; and was deposited with the Collection Nationale de Cultures de Micro- organisms (CNCM), Institute Pasteur by SOCIÉTÉ DES PRODUITS NESTLÉ S.A accordingto the Budapest Treaty on the 29th of March 2023 receiving the deposit number CNCM I-5942.The present B. longum transitional strain is considered to have several advantageouscharacteristics which make it particularly suited for supporting the transition between a milk- based diet and solid in infants and young children, for example when used as a probiotic or as part of a synbiotic.Without wishing to be bound by theory, the present B. longum transitional strain may provideone or more of the following advantages: a) free of antibiotic resistance to the set of antibiotics considered relevant by EFSA;b) a unique Carbohydrate Active EnZyme (CaZy) profile, including the presence of aGH43 subfamily 17 enzyme, that was not characterized to date in the B. longum species;c) advantageous growth on 3-FL; without wishing to be bound by theory, this capacity isbelieved to render the present B. longum transitional strain competitive in the weaninginfant gut environment; d) advantageous growth on a set of food derived fibers (e.g. inulin and arabinan).Overall, the present B. longum transitional strain is particularly adapted to the weaning periodand may perform in this environment better than other B. longum transitional strains. Inaddition, the present B. longum transitional strain may perform better on a diet containing foodderived fiber (e.g. in adulthood) than other B. longum transitional strains.Thus, in a first aspect the present invention provides a composition comprising aBifidobacterium longum transitional microorganism and a HMO mixture consisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), wherein the Bifidobacterium longum transitionalmicroorganism has an Average Nucleotide Identity (ANI) of at least 98% with CNCM I-5942and / or has at least one identifying characteristic of the B. longum transitional strain depositedunder deposit number CNCM I-5942. In a further aspect the invention provides a combination of a Bifidobacterium longumtransitional microorganism and a HMO mixture consisting of 2'-fucosyllactose (2’-FL),difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), wherein the Bifidobacterium longum transitional microorganism has anAverage Nucleotide Identity (ANI) of at least 98% with CNCM I-5942 and / or has at least oneidentifying characteristic of the B. longum transitional strain deposited under deposit numberCNCM I-5942. In a further aspect, the invention provides a composition comprising a Bifidobacterium longumtransitional microorganism and a HMO mixture consisting of 2'-fucosyllactose (2’-FL),difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT) for use in preventing, reducing the risk of and / or treating an infection in asubject, wherein the Bifidobacterium longum transitional microorganism has an AverageNucleotide Identity (ANI) of at least 98% with CNCM I-5942 and / or has at least one identifyingcharacteristic of the B. longum transitional strain deposited under deposit number CNCM I-5942. Suitably, the infection is a viral infection. In a further aspect, the invention provides a composition comprising a Bifidobacterium longumtransitional microorganism and a HMO mixture consisting of 2'-fucosyllactose (2’-FL),difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT) for use in promoting a long-term immune benefit in a subject, wherein theBifidobacterium longum transitional microorganism has an Average Nucleotide Identity (ANI)of at least 98% with CNCM I-5942 and / or has at least one identifying characteristic of the B.longum transitional strain deposited under deposit number CNCM I-5942.In a further aspect, the invention provides a composition comprising a Bifidobacterium longumtransitional microorganism and a HMO mixture consisting of 2'-fucosyllactose (2’-FL),difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT) for use in i) preventing and / or reducing the risk of allergen sensitisationand / or ii) preventing and / or reducing the risk of developing a respiratory condition in a subject,wherein the Bifidobacterium longum transitional microorganism has an Average NucleotideIdentity (ANI) of at least 98% with CNCM I-5942 and / or has at least one identifyingcharacteristic of the B. longum transitional strain deposited under deposit number CNCM I-5942. In some embodiments, the composition or combination further comprises a Bifidobacteriumlongum subsp. infantis and / or Bifidobacterium lactis microorganism.The present inventors have also surprisingly found that the combination of 6HMOs with threeprobiotics (B. l. iuvenis + B. lactis + B. infantis) significantly increased the levels of indole-3-propionic acid as compared to the 6HMOs in combination with either B. l. iuvenis alone or withB. lactis + B. infantis. Indole-3-propionic acid is a microbial derived metabolite that is linkedwith immune benefits (Li et al., Front. Pharmacol., 2021, 12: 769501).Thus, in one aspect the present invention provides a composition comprising aBifidobacterium longum transitional microorganism, Bifidobacterium longum subsp. infantisand a HMO mixture consisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N- fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), whereinthe Bifidobacterium longum transitional microorganism has an Average Nucleotide Identity(ANI) of at least 98% with CNCM I-5942 and / or has at least one identifying characteristic ofthe B. longum transitional strain deposited under deposit number CNCM I-5942. In a further aspect the invention provides a combination of a Bifidobacterium longumtransitional microorganism, Bifidobacterium longum subsp. infantis and a HMO mixtureconsisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'- sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), wherein the Bifidobacteriumlongum transitional microorganism has an Average Nucleotide Identity (ANI) of at least 98%with CNCM I-5942 and / or has at least one identifying characteristic of the B. longumtransitional strain deposited under deposit number CNCM I-5942. In a further aspect, the invention provides a composition comprising a Bifidobacterium longumtransitional microorganism, Bifidobacterium longum subsp. infantis and a HMO mixtureconsisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'- sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I),3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT) for use in preventing, reducing therisk of and / or treating an infection in a subject, wherein the Bifidobacterium longum transitionalmicroorganism has an Average Nucleotide Identity (ANI) of at least 98% with CNCM I-5942and / or has at least one identifying characteristic of the B. longum transitional strain depositedunder deposit number CNCM I-5942. Suitably, the infection is a viral infection.In a further aspect, the invention provides a composition comprising a Bifidobacterium longumtransitional microorganism, Bifidobacterium longum subsp. infantis and a HMO mixtureconsisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'- sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I),3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT) for use in promoting a long-termimmune benefit in a subject, wherein the Bifidobacterium longum transitional microorganismhas an Average Nucleotide Identity (ANI) of at least 98% with CNCM I-5942 and / or has atleast one identifying characteristic of the B. longum transitional strain deposited under depositnumber CNCM I-5942. In a further aspect, the invention provides a composition comprising a Bifidobacterium longumtransitional microorganism, Bifidobacterium longum subsp. infantis and a HMO mixtureconsisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'- sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I),3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT) for use in i) preventing and / orreducing the risk of allergen sensitisation and / or ii) preventing and / or reducing the risk ofdeveloping a respiratory condition in a subject, wherein the Bifidobacterium longumtransitional microorganism has an Average Nucleotide Identity (ANI) of at least 98% withCNCM I-5942 and / or has at least one identifying characteristic of the B. longum transitionalstrain deposited under deposit number CNCM I-5942. In some embodiments, the composition is for use in preventing and / or reducing the risk ofallergen sensitisation in a subject.In some embodiments, the composition is for use in preventing and / or reducing the risk of developing a respiratory condition in a subject. In a further aspect, the invention provides a composition comprising a Bifidobacterium longumtransitional microorganism and a HMO mixture consisting of 2'-fucosyllactose (2’-FL),difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT) for use in preventing and / or reducing the risk of developing asthma in asubject, wherein the Bifidobacterium longum transitional microorganism has an AverageNucleotide Identity (ANI) of at least 98% with CNCM I-5942 and / or has at least one identifyingcharacteristic of the B. longum transitional strain deposited under deposit number CNCM I-5942. In a further aspect, the invention provides a composition comprising a Bifidobacterium longumtransitional microorganism, Bifidobacterium longum subsp. infantis and a HMO mixtureconsisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'- sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I),3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT) for use in preventing and / orreducing the risk of developing asthma in a subject, wherein the Bifidobacterium longumtransitional microorganism has an Average Nucleotide Identity (ANI) of at least 98% withCNCM I-5942 and / or has at least one identifying characteristic of the B. longum transitionalstrain deposited under deposit number CNCM I-5942. The invention further provides a prebiotic for use in preventing and / or reducing the risk of an infection in a subject by promoting the growth and / or survival of a Bifidobacterium longumtransitional microorganism in the gut of the infant or young child, wherein the prebiotic is aHMO mixture consisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose(LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), and wherein theBifidobacterium longum transitional microorganism has an Average Nucleotide Identity (ANI)of at least 98% with CNCM I-5942 and / or has at least one identifying characteristic of the B.longum transitional strain deposited under deposit number CNCM I-5942.The invention also provides a combination of a Bifidobacterium longum transitionalmicroorganism and a HMO mixture for use in preventing, reducing the risk of, and / or treatingan infection in a subject; wherein the HMO mixture consists of 2'-fucosyllactose (2’-FL),difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), and wherein the Bifidobacterium longum transitional microorganism hasan Average Nucleotide Identity (ANI) of at least 98% with CNCM I-5942 and / or has at leastone identifying characteristic of the B. longum transitional strain deposited under depositnumber CNCM I-5942. Suitably, the infection is a viral infection.In a further aspect, the invention provides a combination of a Bifidobacterium longumtransitional microorganism and a HMO mixture consisting of 2'-fucosyllactose (2’-FL),difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT) for use in promoting a long-term immune benefit in a subject, wherein theBifidobacterium longum transitional microorganism has an Average Nucleotide Identity (ANI)of at least 98% with CNCM I-5942 and / or has at least one identifying characteristic of the B.longum transitional strain deposited under deposit number CNCM I-5942.In a further aspect, the invention provides combination of a Bifidobacterium longum transitionalmicroorganism and a HMO mixture consisting of 2'-fucosyllactose (2’-FL), difucosyllactose(DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT)for use in i) preventing and / or reducing the risk of allergen sensitisation and / or ii) preventingand / or reducing the risk of developing a respiratory condition in a subject, wherein theBifidobacterium longum transitional microorganism has an Average Nucleotide Identity (ANI)of at least 98% with CNCM I-5942 and / or has at least one identifying characteristic of the B.longum transitional strain deposited under deposit number CNCM I-5942.The invention also provides a combination of a Bifidobacterium longum transitionalmicroorganism, Bifidobacterium longum subsp. infantis and a HMO mixture for use inpreventing, reducing the risk of, and / or treating an infection in a subject; wherein the HMOmixture consists of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT),6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP- I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), wherein the Bifidobacteriumlongum transitional microorganism has an Average Nucleotide Identity (ANI) of at least 98%with CNCM I-5942 and / or has at least one identifying characteristic of the B. longumtransitional strain deposited under deposit number CNCM I-5942. Suitably, the infection is aviral infection. In a further aspect, the invention provides a combination of a Bifidobacterium longumtransitional microorganism, Bifidobacterium longum subsp. infantis and a HMO mixtureconsisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'- sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I),3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT) for use in promoting a long-termimmune benefit in a subject, wherein the Bifidobacterium longum transitional microorganismhas an Average Nucleotide Identity (ANI) of at least 98% with CNCM I-5942 and / or has atleast one identifying characteristic of the B. longum transitional strain deposited under depositnumber CNCM I-5942.In a further aspect, the invention provides combination of a Bifidobacterium longum transitionalmicroorganism, Bifidobacterium longum subsp. infantis and a HMO mixture consisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT) for use in i) preventing and / or reducing the risk ofallergen sensitisation and / or ii) preventing and / or reducing the risk of developing a respiratorycondition in a subject, wherein the Bifidobacterium longum transitional microorganism has anAverage Nucleotide Identity (ANI) of at least 98% with CNCM I-5942 and / or has at least oneidentifying characteristic of the B. longum transitional strain deposited under deposit numberCNCM I-5942. In some embodiments, the combination is for use in preventing and / or reducing the risk ofallergen sensitisation in a subject.In some embodiments, the combination is for use in preventing and / or reducing the risk of developing a respiratory condition in a subject. In a further aspect, the invention provides a combination of a Bifidobacterium longumtransitional microorganism and a HMO mixture consisting of 2'-fucosyllactose (2’-FL),difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT) for use in preventing and / or reducing the risk of developing asthma in asubject, wherein the Bifidobacterium longum transitional microorganism has an AverageNucleotide Identity (ANI) of at least 98% with CNCM I-5942 and / or has at least one identifyingcharacteristic of the B. longum transitional strain deposited under deposit number CNCM I- In a further aspect, the invention provides a combination of a Bifidobacterium longumtransitional microorganism, Bifidobacterium longum subsp. infantis and a HMO mixtureconsisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'- sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I),3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT) for use in preventing and / orreducing the risk of developing asthma in a subject, wherein the Bifidobacterium longumtransitional microorganism has an Average Nucleotide Identity (ANI) of at least 98% withCNCM I-5942 and / or has at least one identifying characteristic of the B. longum transitionalstrain deposited under deposit number CNCM I-5942.In some embodiments, the Bifidobacterium longum subsp. infantis is Bifidobacterium longumsubsp. infantis LMG 11588.In some embodiments, the Bifidobacterium longum subsp. infantis is a strain having anAverage Nucleotide Identity (ANI) of at least 99.9% to Bifidobacterium longum subsp. infantisLMG 11588.In some embodiments, the Bifidobacterium lactis is Bifidobacterium lactis CNCM 1-3446.In some embodiments, the Bifidobacterium lactis is a strain having an Average NucleotideIdentity (ANI) of at least 99.9% ANI to Bifidobacterium lactis CNCM 1-3446.In some embodiments, the HMO mixture consists of 2’-FL, DFL, LNT, 6SL, and 3SL.In some embodiments, the HMO mixture consists of 2’-FL, DFL, LNT, 6SL, 3SL, and 3-FL.In some embodiments, the HMO mixture consists of 2’-FL, DFL, LNT, 6SL, 3SL, and LNnT.In some embodiments, the HMO mixture consists of 2’-FL, DFL, LNT, 6SL, 3SL, 3-FL, andLNnT.In some embodiments, the HMO mixture consists essentially of:i. 31 wt% to 82 wt% of 2’-FL, preferably 41wt% to 70 wt%;ii. 10 wt% to 27 wt% of LNT, preferably 14 wt% to 23 wt%;iii. 4 wt% to 11 wt% of DFL, preferably 6 wt% to 10 wt%; andiv. 9 wt% to 34 wt% of 6SL and 3SL combined, preferably 11 wt% to 29 wt%.In some embodiments, the HMO mixture consists essentially of:i. 16 wt% to 69 wt% of 2’-FL, preferably 22 wt% to 59 wt%;ii. 9 wt% to 24 wt% of LNT, preferably 12 wt% to 21 wt%;iii. 2 wt% to 10 wt% of DFL, preferably 3 wt% to 8 wt%;iv. 8 wt% to 26 wt% of 6SL and 3SL combined, preferably 11 wt% to 22 wt%;and v. 8 wt% to 50 wt% of 3-FL, preferably 11 wt% to 43 wt%In some embodiments, the HMO mixture consists essentially of:i. 34 wt% to 85 wt% of 2’-FL, preferably 40 wt% to 71 wt%;ii. 10 wt% to 40 wt% of LNT, preferably 12 wt% to 26 wt%;iii. 4 wt% to 14 wt% of DFL, preferably 5 wt% to 10 wt%;iv. 9 wt% to 31 wt% of 6SL and 3SL combined, preferably 10 wt% to 28 wt%and; v. 6 wt% to 30 wt% of LNnT, preferably 7 wt% to 22 wt%.In some embodiments, the HMO mixture consists essentially of:i. 20 wt% to 60 wt% of 2’-FL, preferably 22 wt% to 55 wt%;ii. 4 wt% to 30 wt% of LNT, preferably 6 wt% to 20 wt%;iii. 1 wt% to 12 wt % of DFL, preferably 2 wt% to 8 wt%;iv. 7 wt% to 23 wt% of 6SL and 3SL combined, preferably 8 wt% to 22 wt%;v. 10 wt% to 50 wt% of 3-FL, preferably 13 wt% to 46 wt% andvi. 3 wt% to 25 wt% of LNnT, preferably 5 wt% to 20 wt%.In some embodiments, the composition is in the form of a nutritional composition.In some embodiments, the nutritional composition is selected from an infant formula, a starter infant formula, a follow-on or follow-up formula, a baby food, an infant cereal composition, a growing-up-milk, a fortifier such as a human milk fortifier, or a supplement. In some embodiments, the subject is an infant, a young child or a child. Preferably, the subject is an infant or a young child. In some embodiments, the subject is an infant. In some embodiments, the subject is a young child. In some embodiments, the subject is a child. Brief Description of the DrawingsFigure 1 - Average Nucleotide Identity (ANI) UPGMA based phylogenetic tree of strainsbelonging to the B. longum species. The scale represents the percentage of identity at eachbranch point.Figure 2 - Short chain fatty acids (SCFAs) production (i.e acetate, butyrate and propionate)over 48h of batch fermentation with 3-fucosylactose (3-FL). A. Heatmap shows the z score ofthe Nuclear magnetic resonance (NMR) peak intensity of 3-FL, TCA cycle, SCFAsintermediates and SCFAs. Three conditions were tested, i.e., fermentation with nosupplementation, supplementation with B. longum transitional strain (NCC5004), orsupplementation with B. longum subsp. infantis (NCC3089). Each condition was performed intriplicate using one baby fecal inoculum. Samples were collected at the beginning (T0) at 24h (T24) and at the end of the fermentation (T48). B. Abundance of B. longum transitional strain(NCC5004) and B. longum subsp. infantis (NCC3089) at T0, T24 and T48 of batchfermentation with 3-FL as measured by strain specific qPCR.Figure 3 - Short chain fatty acids (SCFAs) production (i.e. acetate, butyrate and propionate)over 48h of batch fermentation with pea fiber rich in arabinan. A. Heatmap shows the z scoreof the Nuclear magnetic resonance (NMR) peak intensity of TCA cycle, SCFAs intermediatesand SCFAs. Three conditions were tested, i.e., fermentation with no supplementation,supplementation with B. longum transitional strain (NCC5002), or supplementation with B.longum subsp. infantis (NCC3089). Each condition was performed in triplicate using one babyfecal inoculum. Samples were collected at the beginning (T0) at 24 h (T24) and at the end ofthe fermentation (T48). B. Abundance of B. longum transitional strain (NCC5002) and B.longum subsp. infantis (NCC3089) at T0, T24 and T48 of batch fermentation with pea fiber asmeasured by strain specific qPCR.Figure 4 – Interleukin 6 (IL-6) production by monocytes following training with differentprobiotics and stimulated thereafter with LPS. Bars represent median IL-6 response withdotted line demonstrating the IL-6 level by untrained monocytesFigure 5 - Transepithelial electrical resistance (TEER) of Caco-2 monolayers incubated withtransitional B. longum NCC5002 (black line), B. lactis NCC2818 (grey line) or vehicle (dottedline) for 24h followed by a challenge with pro-inflammatory cytokines.Figure 6 - Measurement of the flux of micromolecules across Caco-2 cell monolayers afterincubation with transitional B. longum NCC5002 (black line), B. lactis NCC2818 (grey line) orvehicle (dotted line) followed by a challenge with pro-inflammatory cytokines.Figure 7 - Representation of glycoside hydrolases (GH) and polysaccharide lyases (PL) in thegenomes of the B. longum clade. Heatmap shows presence (light) and absence (dark) of GHand PL genes, and the size of the circles represent the number of these genes per genome of a particular strain.Figure 8 - Growth of B. longum transitional strain NCC5001 was promoted in a complex gutmicrobiota community by pectin (sugar beet) and arabinogalactan (larch wood). P **** < 0.0001, *** <0.001, ** <0.01, * <0.05, one-way ANOVA with uncorrected Fisher's LSD.Figure 9 - Growth of B. longum transitional strain NCC5002 was promoted in a complex gutmicrobiota community by arabinogalactan (larch wood) and starch (potato). P **** < 0.0001,*** <0.001, ** <0.01, * <0.05, one-way ANOVA with uncorrected Fisher's LSD.Figure 10 – UPGMA phylogenetic tree of B. Longum genomesFigure 11 - Schematic representation of the organization of the genes implicated in thedegradation and the metabolization of fucosylated human milk oligosaccharides in the B.longum transitional strains, compared to B. longum subsp. infantis ATCC 15697 and B.kashiwanohense DSM 21854. Values represent percentage (%) of identity between thedifferent genes.Figure 12 - Growth of B. longum transitional strains and B. longum subsp. infantis LMG 11588on glucose, 2’-FL or 3-FL as sole carbon source (0.5% final). Significant differences between 2’-FL and 3-FL growth for each strain were calculated using one-way ANOVA, followed by a Sidak’s multiple comparison test (ns=non-significant, * p-value <0.05, ** p-value <0.01).Figure 13 - Growth ratios of 3-FL over 2’-FL of B. longum transitional strains and B. longumsubsp. infantis LMG 11588.Figure 14 - Schematic of model of early life viral airway infection and pollution enhancedallergic airway inflammation.Figure 15 - Early life nutritional intervention with synbiotic (B. infantis + 6HMOs) reduces virus-induced lung pathology.Figures 16 and 17 - Early life nutritional intervention with synbiotic (B. infantis + 6HMOs)promotes sustained immune benefits into adulthood.Figure 18 - Early life nutritional intervention with synbiotic (B. infantis + 5HMOs) promotesanti-viral immune responses at peak of infection and reduces virus-induced lung inflammation.Figure 19 - Schematics of the experimental set up for a preclinical model for efficacy testingof B. longum transitional strain in infection model.Figure 20 – Kinetics of weight change following airway viral infection with pneumonia virus ofmice from 0 to 10 dpi. Each dot represents the mean with error bars indicating standard error of the mean with N=8 / experimental group. Statistical difference between different groups was calculated by a 2way ANOVA.*,£p value <0.05,**, ££p value <0.005,$$$, $$$$p value < 0.0001.Figure 21 - The effect of the combination of B. l. iuvenis (Bj) with B. infantis (Bi), B. lactis (Bl)and 6 HMOs on boosting a microbial derived metabolite that is linked with immune benefits.The effect of 6HMOs in combination with (i) B. infantis and B. lactis (BlBi), (ii) B. l. iuvenis (Bj)or (iii) B. l. iuvenis, B. infantis and B. lactis (BjBlBi) was tested, with N=12 / experimental group.Statistical difference between different groups was calculated by non-parametric ANOVA test (Friedman test), nominal p-value reported.Figure 22 - Carbohydrate-Active Enzymes (CAZymes) harbored by B. longum transitionalstrains, including NCC 5025.Figure 23 - The genetic region of NCC 5025 encompassing the unique GH43_17 encodinggene.Figure 24 - Growth profile of B. longum transitional strains, including NCC 5025 on 3-FL assole carbon source. The final panel represents the obtained growth rates k for each tested strain.Figure 25 – Growth profile of different B. longum transitional strains on A) Inulin and B)Arabinan as a substrate. Detailed Description of the invention All percentages are by weight unless otherwise stated. The terms “about” or “approximatively” as used herein when referring to a measurable value such as a parameter, an amount, a temporal duration, and the like, are meant to encompass variations of and from the specific value, such as the variation of 1 / -10% or less, 1 / -5% or less, 1 / -1% or less, and + / 0.1% or less of and from the specific value, insofar such variations are appropriate to perform in the disclosed invention. It is to be understood that the value to which the modifier “about” or “approximately” refers is itself also specifically, and preferably, disclosed. The terms “subject”, “individual” and “patient” are used interchangeably to refer to a vertebrate, preferably a mammal, more preferably a human. Mammals include but are not limited to murines, simians, humans, farm animals, sport animals and pets. The term “infant” means a human subject under the age of 12 months or an age equivalent non-human animal. The terms “young child” or “toddler” as used herein may mean a human subject aged between 12 months and 5 years of age. Suitably, a “young child” may refer to an age equivalent non- human animal. The term “child” means a human child aged between three and twelve years. Preferably, the term “child” means a child aged between three and six years. A "preterm" or "premature" subject means an infant or young child who was not born at term. Generally it refers to an infant or young child born prior 36 weeks of gestation. By the expression "small for gestational age" or "SGA" it is referred to an infant or young child who is smaller in size than normal for their gestational age at birth, most commonly definedas a weight below the 10th percentile for the gestational age. In some embodiments, SGAmay be associated with intrauterine growth restriction (IUGR), which refers to a condition in which a foetus is unable to achieve its potential size.By the expression “low birth weight”, it should be understood as any body weight under 2500gat birth. The expressions “complementary feeding period”, “complementary period”, “transitional period”, “transitional feeding period” and “weaning period” can be interchangeably used and refer to the period during which the milk, either breast milk or formula, is substituted by otherfoods in the diet of an infant or a young child. The infant or the young child is typically movedor transitioned gradually from exclusive milk-feeding, either breast feeding or formula feeding, to mixed diet comprising milk and / or solid foods. The transitional period depends on the infant or young child but typically falls between about 4 months and about 18 months of age, such as between about 6 and about 18 months of age, but can in some instances extend up to about 24 months or more. For humans, the weaning period typically starts between 4 and 6 months of age and is considered completed once the infant and / or the young child is no longer fed with breast milk or infant formula, typically at about 24 months of age. In some embodiments, the weaning period is between 4 and 24 months. The expressions “composition” or “nutritional composition” refer to any kind of composition or formulation that provides a nutritional benefit to an individual and that may be safely consumedby a human or an animal. A nutritional composition may be in solid (e.g. powder), semi-solidor liquid form and may comprise one or more macronutrients, micronutrients, food additives, water, etc. For instance, the nutritional composition may comprise the following macronutrients: a source of proteins, a source of lipids, a source of carbohydrates and any combination thereof. Furthermore, the nutritional composition may comprise the following micronutrients: vitamins, minerals, fiber, phytochemicals, antioxidants, prebiotics, probiotics, bioactives, metabolites (e.g. butyrate, Docosahexaenoic acid (DHA), Eicosapentaenoic acid (EPA), Gamma-Linolenic acid (GLA)) and any combination thereof. The composition may also contain food additives such as stabilizers (when provided in liquid or solid form) or emulsifiers (when provided in liquid form). The amount of the various ingredients (e.g. the oligosaccharides) can be expressed in g / 100 g of composition on a dry weight basis when it is in a solid form, e.g. a powder, or as a concentration in g / L of the composition when it refers to a liquid form (this latter also encompasses liquid composition that may be obtained from apowder after reconstitution in a liquid such as milk, water, e.g. a reconstituted infant formulaor follow-on / follow-up formula or infant cereal product or any other formulation designedfor infant or young child nutrition). Generally, a nutritional composition can be formulated tobe taken enterally, orally, parenterally, or intravenously, and it usually includes one of more nutrients selected from: a lipid or fat source, a protein source, and a carbohydrate source. Preferably, a nutritional composition is for oral use. In a particular embodiment, the nutritional composition is a “synthetic nutritional composition”. The expression “synthetic nutritional composition” means a mixture obtained by chemical and / or biological means. The expression "infant formula" as used herein refers to a foodstuff intended for particular nutritional use by infants during the first months of life and satisfying by itself the nutritional requirements of this category of person (Article 2(c) of the European Commission Directive91 / 321 / EEC 2006 / 141 / EC of 22 December 2006 on infant formulae and follow-on formulae).It also refers to a nutritional composition intended for infants and as defined in Codex Alimentarius (Codex STAN 72-1981) and Infant Specialities (incl. Food for Special Medical Purpose). The expression "infant formula" encompasses both “starter infant formula” and “follow-up formula” or “follow-on formula”. A “follow-up formula” or “follow-on formula” is given from the 6th month onwards. It constitutes the principal liquid element in the progressively diversified diet of this category of person. The expression “baby food” means a foodstuff intended for particular nutritional use by infants or young children during the first years of life. The expression “infant cereal composition” means a foodstuff intended for particular nutritional use by infants or young children during the first years of life. The expression “growing-up milk” (or GUM) refers to a milk-based drink generally with added vitamins and minerals, that is intended for young children or children. The terms “fortifier” refers to liquid or solid nutritional compositions suitable for fortifying or mixing with human milk, infant formula, growing-up milk or human breast milk fortified with other nutrients. Accordingly, the fortifier can be administered after dissolution in human breast milk, in infant formula, in growing-up milk or in human breast milk fortified with other nutrients or otherwise it can be administered as a stand-alone composition. When administered as a stand-alone composition, the milk fortifier can be also identified as being a “supplement”. The term “metabolize” is used herein to mean that a substrate can by broken down, adsorbed and / or utilized by a microorganism. For example, the substrate may promote and / or contribute to the growth and / or survival of the microorganism.Suitably, the term “capable of metabolizing the glycan substrate” may mean that the B. longumtransitional strain encodes at least one CAZyme which is capable of utilizing the glycan substrate. For example, the CAZyme may be capable of catalyzing the hydrolysis of aglycosidic bond within the glycan substrate. Suitably, the B. longum transitional strain mayencode at least one, at least two, at least three, at least four or at least five CAZymes that arecapable of utilizing the glycan substrate. Suitably, the term “capable of metabolizing the glycansubstrate” may mean that the glycan substrate (or a fiber or ingredient comprising the glycansubstrate) is capable of promoting growth and / or survival of the B. longum transitional strain(e.g. when added to an anaerobic culture of the B. longum transitional strain). Growth and / orsurvival of the B. longum transitional strain may be determined by measuring the abundanceof 16S rDNA – for example using PCR methods. An illustrative assay for measuring growthof a B. longum transitional strain in the presence of glycan substrates (e.g. in the form of fiber)is provided in the present examples.Suitably, the glycan substrate is capable of being metabolized by the B longum transitionalmicroorganism. Suitably, the glycan substrate may be capable of promoting growth and / orsurvival of the B. longum transitional strain. Glycan substrates capable of promoting growthand / or survival of the B. longum transitional strain may be determined by e.g. anaerobic cultureof the B. longum transitional strain with the glycan substrate to be tested. Growth and / orsurvival of the B. longum transitional strain may be determined by measuring bacteria cell number, cell density (e.g. measured by optical density) and / or the abundance of 16S rDNA – for example using PCR methods. An illustrative assay for measuring growth of a B. longumtransitional strain in the presence of glycan substrates is provided in the Examples. A glycansubstrate capable of promoting growth and / or survival of the B. longum transitional strain mayincrease the number of B. longum transitional bacteria in an anaerobic culture by at least 20%,at least 30%, at least 40%, at least 50%, at least 75% or at least 100% compared to thenumber of B. longum transitional bacteria in a control anaerobic culture which does notcomprise the HMO. Suitably, a glycan substrate capable of promoting growth and / or survivalof the B. longum transitional strain may increase the number of B. longum transitional bacteriain an anaerobic culture by a statistically significant amount (e.g. p-value <0.05 as determinedby one-way ANOVA) compared to the number of B. longum transitional bacteria in a controlanaerobic culture which does not comprise the glycan substrate. A “glycan substrate” refers to a glycan that can be metabolized by a microorganism. A glycansubstrate may be, for example, a glycoconjugate, oligo- or polysaccharide. Glycoconjugateglycans may comprise N-linked glycans or O-linked glycans within glycoproteins and proteoglycans, or glycolipids. For example, an O-linked glycan may comprise a protein or peptide where the oxygen atom of a serine or threonine residue is linked to a monosaccharide,oligo- or polysaccharide as in the case with glycosaminoglycans (GAGs). Further examplesof “glycan substrates” are cellulose, which is a glycan composed of β-1,4-linked D-glucose, and chitin, which is a glycan composed of β-1,4-linked N-acetyl-D-glucosamine. Glycans maybe homo- or heteropolymers of monosaccharide residues and can be linear or branched.“Glycan substrate” as used herein encompasses, for example, oligosaccharides and polysaccharides. The “oligosaccharide” may refer to a carbohydrate that has greater than 2 but relatively few monosaccharide units (typically 3, 4, 5, 6, and up to 10). Exemplary oligosaccharides include, but are not limited to, fructo-oligosaccharides, galacto-oligosaccharides (raffinose, stachyose, verbascose), maltooligosaccharides, gentio-oligosaccharides, cellooligosaccharides, milk oligosaccharides (e.g., those present in secretions from mammary glands), isomalto- oligosaccharides, lactosucrose, mannooligosaccharides, melibiose-derived oligosaccharides, pectic oligosaccharides, xylo-oligosaccharides. The term “polysaccharide” may refer to a carbohydrate that has more than ten monosaccharide units. Exemplary polysaccharides include, but are not limited to, starch, arabinogalactan, laminarin, chrysolaminarin, xylan, arabinoxylan, mannan, fucoidan and galactomannan. It is to be understood that there is not a precise cut-off or distinction between the terms oligosaccharide and polysaccharide, nor is such a distinction necessary to practice the invention. The term “glycosaminoglycan” (GAG) or mucopolysaccharide refers to long linear polysaccharides consisting of repeating disaccharide units (i.e. two-sugar units). Therepeating two-sugar unit consists of a uronic sugar and an amino sugar, with the exception ofkeratan, where in the place of the uronic sugar it has galactose. GAGs are classified into four groups based on core disaccharide structures. “Mucins”, as used herein, may refer to a family of high molecular weight, heavily glycosylated proteins (glycoconjugates). Mucins' key characteristic is their ability to form gels; therefore they are a key component in most gel-like secretions, serving functions from lubrication to cell signaling to forming mechanical and chemical barriers. The term “HMO” or “HMOs” refers to human milk oligosaccharide(s). These carbohydrates are highly resistant to enzymatic hydrolysis, indicating they may display essential functions not directly related to their caloric value. It has been especially illustrated they play a vital role in the early development of infants and young children, such as the maturation of the immune system. Many different kinds of HMOs are found in the human milk. Each individual oligosaccharide is based on a combination of glucose, galactose, sialic acid (N- acetylneuraminic acid), fucose and / or N-acetylglucosamine with many and varied linkages between them, thus accounting for the enormous number of different oligosaccharides inhuman milk – over 130 such structures have been identified so far. Almost all of them have alactose moiety at their reducing end while sialic acid and / or fucose (when present) occupy the terminal position at the non-reducing ends. Depending on the presence of fucose and sialic acid in the oligosaccharide structure, the HMOs can be divided as non-fucosylated (neutral) or fucosylated (neutral) and sialylated (acidic) and non-sialylated molecules, respectively. The expression “fucosylated oligosaccharide” refers to an oligosaccharide having a fucose residue. It has a neutral nature. Some examples are 2’-fucosyllactose (2’-FL), 3-fucosyllactose (3-FL), difucosyllactose (DiFL), lacto-N-fucopentaose (e.g. lacto-N-fucopentaose I, lacto-N- fucopentaose II, lacto-N-fucopentaose III, lacto-N-fucopentaose V), lacto-N-fucohexaose, lacto-N-difucohexaose I, fucosyllacto-N-hexaose, fucosyllacto-N-neohexaose, difucosyllacto- N-hexaose I, difucosyllacto-N-neohexaose II and any combination thereof. Fucosylated oligosaccharides represents the largest fraction of human milk with 2’-FL constituting up to 30% of the total HMOs. Fucosylated oligosaccharides are thought to reduce the risk of infections and inflammations and to boost growth and metabolic activity of specific commensal microbes reducing inflammatory response. The expression “N-acetylated oligosaccharide(s)” encompasses both “N-acetyl-lactosamine” and “oligosaccharide(s) containing N-acetyl-lactosamine”. They are neutral oligosaccharides having an N-acetyl-lactosamine residue. Suitable examples are LNT (lacto-N-tetraose), para-lacto-N-neohexaose (para-LNnH), LNnT (lacto-N-neotetraose), DSLNT (disialyllacto-N-tetraose), and any combinations thereof. Other examples are lacto-N-hexaose, lacto-N-neohexaose, para- lacto-N-hexaose, para-lacto-N-neohexaose, lacto-N-octaose, lacto-N-neooctaose, iso- lacto-N-octaose, para- lacto-N-octaose and lacto-N-decaose.The expressions “at least one fucosylated oligosaccharide” and “at least one N-acetylated oligosaccharide” should be understood as “at least one type of fucosylated oligosaccharide” and “at least one type of N-acetylated oligosaccharide”. The term “sialylated oligosaccharide” refers to an oligosaccharide having a charged sialic acid residue. It has an acidic nature. Some examples are 3’-sialyllactose (3-SL), 6’-sialyllactose (6-SL), sialyllacto-N-tetraose (Lst – e.g. Lst-a, Lst-b or Lst-c).Suitably, the term “capable of metabolizing the HMO” may mean that the B. longum transitionalstrain encodes at least one CAZyme which is capable of utilizing the HMO. For example, the CAZyme may be capable of catalyzing the hydrolysis of a glycosidic bond within the HMO.Suitably, the B. longum transitional strain may encode at least one, at least two, at least three,at least four or at least five CAZymes that are capable of utilizing the HMO. Suitably, the term “capable of metabolizing the HMO” may mean that the HMO is capable of promoting growthand / or survival of the B. longum transitional strain (e.g. when added to an anaerobic cultureof the B. longum transitional strain). Growth and / or survival of the B. longum transitional strainmay be determined by measuring the abundance of 16S rDNA – for example using PCRmethods. The term fibers is used herein to refer to carbohydrates that are indigestible by a human or animal. Such fibers are also discussed in relation to carbohydrates herein. Suitably, the fiber can be fermented by one or more B. longum transitional microorganisms provided in the present use or composition and / or within one or more regions in the gastrointestinal tract within an organism, such as a human or non-human animal. As used herein, the expressions “fiber” or “fibers” or “dietary fiber” or “dietary fibers” within the context of the present invention indicate the indigestible portion, in small intestine, of food derived from plants which comprises two main components: soluble fiber, which dissolves in water and insoluble fiber. Mixtures of fibers are comprised within the scope of the terms above mentioned. Soluble fiber is readily fermented in the colon into gases and physiologically active byproducts and can be prebiotic and viscous. Insoluble fiber does not dissolve in water, is metabolically inert and provides bulking, or it can be prebiotic and metabolically ferment in the large intestine. Chemically, dietary fiber consists of carbohydrate polymers with three or more monomeric units which are not hydrolyzed by endogenous enzymes in the small intestine such as arabinoxylans, cellulose, and many other plant components such as resistant starch, resistant dextrins, inulin, lignin, chitins, pectins, arabinans, arabinogalactans, galactans, xylans, beta-glucans, and oligosaccharides. Non-limiting examples of dietary fibers are: prebiotic fibers such as Fructo- oligosaccharides (FOS), inulin, galacto-oligosaccharides (GOS), fruit fiber, vegetable fiber, cereal fiber, resistant starch such as high amylose corn starch. As used herein, “added fiber” or “added dietary fiber” indicates an ingredient mainly or totally constituted by fiber which is added to the complementary nutritional composition and whose content in fiber contributes to the total fiber content of the composition. The total fiber content of the complementary nutritional composition is provided by the sum of amount of fibernaturally present in ingredients used in the recipe (for example from whole grain cereal flour)plus amount of added fiber. The term “prebiotic” means non-digestible carbohydrates that beneficially affect the host by selectively stimulating the growth and / or the activity of healthy bacteria such as bifidobacteria in the colon of humans (Gibson GR, Roberfroid MB. Dietary modulation of the human colonic microbiota: introducing the concept of prebiotics. J Nutr.1995;125:1401-12). The term “probiotic” means microbial cell preparation or components of microbial cells with a beneficial effect on the health or well-being of the host (Salminen S, Ouwehand A. Benno Y. et al. “Probiotics: how should they be defined” Trends Food Sci. Technol.1999:10107-10). The microbial cells according to the present invention are generally bacteria. The term “cfu” should be understood as colony forming unit. The “gut microbiota” is the composition of microorganisms (including bacteria, archaea and fungi) that live in the digestive tract. The term “gut microbiome” may encompass both the “gut microbiota” and their “theater of activity”, which may include their structural elements (nucleic acid, proteins, lipids, polysaccharides), metabolites (signaling molecules, toxins, organic and inorganic molecules) and molecules produced by coexisting hosts and structured by the surrounding environmental conditions (Berg, G., et al., 2020. Microbiome, 8(1), pp.1-22). The term “SCFA” means short chain fatty acid(s). The expression “increasing SCFA production” means that the amount of systemic and / or colonic SCFA, is higher in an individual fed with the nutritional composition according to the present invention in comparison with a standard. The SCFA production may be measured by techniques known by the skilled person such as by Gas-Liquid Chromatography. In the present context, the term “gastrointestinal tract” includes the mouth, pharynx, oesophagus, stomach, small intestine, large intestine, rectum and anus. The term “intestine” includes the small intestine, the large intestine and rectum. In the present context, the term “respiratory tract” refers to the passage formed by the nose, nasal cavity, pharynx, larynx, trachea, bronchi and the lungs through which air passes during breathing. Composition The present inventors have surprisingly found that the combination of a Bifidobacteriumlongum transitional microorganism and a HMO mixture consisting of 2'-fucosyllactose (2FL),difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose(3SL), and optionally 3-fucosyllactose (3FL) and / or lacto-N-neotetraose (LNnT) in early lifeprovides beneficial effects on preventing and / or reducing the risk of developing infection.That the specific combination of a Bifidobacterium longum transitional microorganism and aHMO mixture consisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose(LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I(LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT) is effective for preventingand / or reducing the risk of developing infection is surprising. Accordingly, in one aspect, theinvention provides a composition comprising a Bifidobacterium longum transitionalmicroorganism and a HMO mixture consisting of 2'-fucosyllactose (2’-FL), difucosyllactose(DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT),wherein the Bifidobacterium longum transitional microorganism has an Average NucleotideIdentity (ANI) of at least 98% with CNCM I-5942 and / or has at least one identifyingcharacteristic of the B. longum transitional strain deposited under deposit number CNCM I-5942. In a further aspect, the invention provides a nutritional composition comprising a Bifidobacterium longum transitional microorganism and a HMO mixture consisting of 2'- fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), wherein the Bifidobacterium longum transitionalmicroorganism has an Average Nucleotide Identity (ANI) of at least 98% with CNCM I-5942and / or has at least one identifying characteristic of the B. longum transitional strain depositedunder deposit number CNCM I-5942. In a further aspect, the invention provides a combination comprising or consisting of aBifidobacterium longum transitional microorganism and a HMO mixture consisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT) wherein the Bifidobacterium longum transitionalmicroorganism has an Average Nucleotide Identity (ANI) of at least 98% with CNCM I-5942and / or has at least one identifying characteristic of the B. longum transitional strain depositedunder deposit number CNCM I-5942. Preferably, the combination consists of theBifidobacterium longum transitional microorganism and a HMO mixture consisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3- FL) and / or lacto-N-neotetraose (LNnT).In one aspect, the invention provides a composition comprising a Bifidobacterium longumtransitional microorganism, Bifidobacterium longum subsp. infantis and 2'-fucosyllactose (2’-FL), wherein the Bifidobacterium longum transitional microorganism has an AverageNucleotide Identity (ANI) of at least 98% with CNCM I-5942 and / or has at least one identifyingcharacteristic of the B. longum transitional strain deposited under deposit number CNCM I-5942.In one embodiment, the composition further comprises Bifidobacterium longum subsp. infantisand / or Bifidobacterium lactis. Suitably, the composition further comprises Bifidobacteriumlongum subsp. infantis. Suitably, the composition further comprises Bifidobacterium lactis.Preferably, the composition further comprises Bifidobacterium longum subsp. infantis andBifidobacterium lactis. The present inventors have also surprisingly found that symbiotic intervention with thecombination of 6HMO with three probiotic strains (namely, B. l. iuvenis, B. infantis and B.lactis) increased the levels of metabolite indole-3-propionic acid by comparison to 6HMO withB. l. iuvenis alone or 6HMO with the two strains B. infantis and B. lactis.Accordingly, in one aspect, the invention provides a composition comprising a Bifidobacteriumlongum transitional microorganism, Bifidobacterium longum subsp. infantis and a HMOmixture consisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP- I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), wherein the Bifidobacteriumlongum transitional microorganism has an Average Nucleotide Identity (ANI) of at least 98%with CNCM I-5942 and / or has at least one identifying characteristic of the B. longumtransitional strain deposited under deposit number CNCM I-5942. In a further aspect, the invention provides a nutritional composition comprising aBifidobacterium longum transitional microorganism, Bifidobacterium longum subsp. infantisand a HMO mixture consisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N- tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N- fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), whereinthe Bifidobacterium longum transitional microorganism has an Average Nucleotide Identity(ANI) of at least 98% with CNCM I-5942 and / or has at least one identifying characteristic ofthe B. longum transitional strain deposited under deposit number CNCM I-5942.In a further aspect, the invention provides a combination comprising or consisting of aBifidobacterium longum transitional microorganism, Bifidobacterium longum subsp. infantisand a HMO mixture consisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N- tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N- fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), whereinthe Bifidobacterium longum transitional microorganism has an Average Nucleotide Identity(ANI) of at least 98% with CNCM I-5942 and / or has at least one identifying characteristic ofthe B. longum transitional strain deposited under deposit number CNCM I-5942. Preferably,the combination consists of the Bifidobacterium longum transitional microorganism,Bifidobacterium longum subsp. infantis and a HMO mixture consisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N- neotetraose (LNnT). In one embodiment, the composition further comprises Bifidobacterium lactis.In one embodiment, the combination comprises or consists of the Bifidobacterium longumtransitional microorganism, a HMO mixture, Bifidobacterium longum subsp. infantis,andBifidobacterium lactis, wherein the HMO mixture consists of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N- neotetraose (LNnT).Preferably, the combination consists of the Bifidobacterium longum transitionalmicroorganism, and a HMO mixture consisting of 2'-fucosyllactose (2’-FL), difucosyllactose(DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT).Preferably, the combination includes Bifidobacterium longum subsp. infantis. Suitably, thecombination includes Bifidobacterium lactis. Preferably, the combination includesBifidobacterium longum subsp. infantis and Bifidobacterium lactis.Bifidobacterium longum transitional microorganismBifidobacterium longum subsp microorganisms of a clade that is present in the gut microbiomeof the transitional feeding period of mammals, particularly humans, have previously beenidentified. B. longum microorganisms belonging to this clade are referred to herein asBifidobacterium longum transitional (B. longum transitional) and are also known in the art asB. longum subsp. iuvenis. B. longum transitional strains NCC 5000, NCC 5001, NCC 5002,NCC 5003 and NCC 5004 were deposited with the Collection nationale de cultures de micro-organisms (CNCM), Institute Pasteur (INSTITUT PASTEUR, 25 RUE DU DOCTEUR ROUX,F-75724 PARIS CEDEX 15, FRANCE) by SOCIÉTÉ DES PRODUITS NESTLÉ S.A accordingto Budapest Treaty on 11th of May 2021 receiving the deposit numbers CNCM I-5683, CNCM I-5684, CNCM I-5685, CNCM I-5686 and CNCM I-5687, respectively. In US provisional patentapplication 63 / 216127, it was shown that the B. longum transitional microorganisms aregreater in relative abundance during the transitional feeding period (e.g. weaning period) thaneither B. longum subsp. infantis (B. infantis) or B. longum subsp longum. Indeed, the relativeabundance of B. longum subsp. infantis decreases at the beginning of the transitional feedingperiod until the end of the transitional feeding period while B. longum subsp. longum beginsto increase in abundance. Vatanen et al. demonstrated that this distinct Bifidobacteriumlongum clade expanded with introduction of solid foods and harbored enzymes for utilizingboth breast milk and solid food substrates (Vatanen et al.; 2022, Cell 185, 1–18; publishedonline 1 November 2022; https: / / doi.org / 10.1016 / j.cell.2022.10.011).B. longum subsp. iuvenis strain NCC 5025 was deposited with the Collection Nationale deCultures de Micro-organisms (CNCM), Institute Pasteur by SOCIÉTÉ DES PRODUITS NESTLÉ S.A according to Budapest Treaty on the 29thof March 2023 receiving the deposit number CNCM I-5942.The Bifidobacterium longum transitional microorganism for use according to the invention hasan Average Nucleotide Identity (ANI) of at least 98% with CNCM I-5942 and / or has at leastone identifying characteristic of the B. longum transitional strain deposited under depositnumber CNCM I-5942.Suitably, the Bifidobacterium longum transitional microorganism for use according to theinvention has an Average Nucleotide Identity (ANI) of at least 98% with CNCM I-5942.Suitably, the Bifidobacterium longum transitional microorganism for use according to theinvention has at least one identifying characteristic of the B. longum transitional straindeposited under deposit number CNCM I-5942. Suitably, the Bifidobacterium longumtransitional microorganism for use according to the invention has an Average NucleotideIdentity (ANI) of at least 98% with CNCM I-5942 and has at least one identifying characteristicof the B. longum transitional strain deposited under deposit number CNCM I-5942.Suitably, the B. longum subsp. iuvenis may be B. longum subsp. iuvenis NCC 5025. Suitably,the B. longum transitional microorganism may be a Bifidobacterium longum transitionalmicroorganism strain deposited with CNCM under deposit number CNCM I-5942 or a B.longum transitional strain having at least one identifying characteristic of the B. longumtransitional strain deposited under deposit number CNCM I-5942. Suitably, an identifying characteristic of the present B. longum transitional strain may refer to one or more of the phenotypic or genotypic characteristics described herein.In another aspect, the present invention provides a B. longum transitional microorganismstrain which has an Average Nucleotide Identity (ANI) of at least 99% to the B. longumtransitional strain deposited with the CNCM under deposit number CNCM I-5942.In some embodiments, the B. longum transitional strain has an ANI of at least at least 99.0%,at least 99.1%, at least 99.2%, at least 99.3%, at least 99.4%, at least 99.5%, at least 99.6%,at least 99.7%, at least 99.8%, or at least 99.9%, compared to the B. longum strain depositedwith the CNCM under deposit number CNCM I-5942.Preferably, the B. longum transitional strain has an ANI of at least 99.9% compared to the B.longum strain deposited with the CNCM under deposit number CNCM I-5942.Suitably, the B. longum transitional strain has an ANI of at least 98.1%, at least 98.2%, at least98.3%, at least 98.4%, of at least 98.5%, of at least 98.6%, of at least 98.6 %, of at least 98.7%, of at least 98.8 %, of at least 98.9 %, of at least 99 %, of at least 99.1 %, of at least 99.2%, of at least 99.3 %, of at least 99.4 %, of at least 99.5 %, of at least 99.6 %, of at least 99.7%, of at least 99.8 %, or of at least 99.9 % compared to the B. longum strain deposited withthe CNCM under deposit number CNCM I-5942 and has at least one identifying characteristicsof the B. Longum transitional strain deposited under deposit number CNCM I-5942 – asdescribed herein.Suitably, the B. longum transitional strain has an ANI of at least 98.4%, of at least 98.5%, ofat least 98.6%, of at least 98.6 %, of at least 98.7 %, of at least 98.8 %, of at least 98.9 %, of at least 99 %, of at least 99.1 %, of at least 99.2 %, of at least 99.3 %, of at least 99.4 %, of at least 99.5 %, of at least 99.6 %, of at least 99.7 %, of at least 99.8 %, or of at least 99.9 %compared to the B. longum strain deposited with the CNCM under deposit number CNCM I-5942 and has at least one identifying characteristics of the B. longum transitional straindeposited under deposit number CNCM I-5942 – as described herein.Methods for sequencing microbial genomes are well known in the art (see e.g. Segerman; Front. Cell. Infect. Microbiol.; 2020; 10; Article 527102 & Donkor; Genes; 2013; 4(4); 556-572). By way of example, metagenomics methods may be used. Suitable metagenomics methods may be performed using shotgun sequencing data, for example. Suitable metogenomics methods are known in the art and include MetaPhlAn 3.0, for example (see Beghini et al.; eLife 2021;10: e65088; https: / / huttenhower.sph.harvard.edu / metaphlan). The “Average Nucleotide Identity (ANI)” is a term of art that refers to a distance-based approach to delineate species based on pair-wise comparisons of their genome sequencesand is an in silico alternative to the traditional DNA-DNA hybridization (DDH) techniques thathave been used for phylogenetic definition of a species (Goris et al., 2007, “DNA-DNAhybridization values and their relationship to whole-genome sequence similarities”, Int. J. Syst.Evol. Microbiol.57: 81-91). Based on DDH, strains with greater than 70% relatedness wouldbe considered to belong to the same species (see e.g., Wayne et al., 1987, Report of the Ad-Hoc-Committee on Reconciliation of Approaches to Bacterial Systematics. Int J SystBacteriol 37: 463-464). ANI is similar to the aforementioned 70% DDH cutoff value and canbe used for species delineation. ANI has been evaluated in multiple labs and has become the gold standard for species delineation (see e.g., Kim et al., 2014, “Towards a taxonomiccoherence between average nucleotide identity and 16S rRNA gene sequence similarity forspecies demarcation of prokaryotes”, Int. J. Syst. Evol. Micr.64: 346-351; Richter et al., 2009,“Shifting the genomic gold standard for the prokaryotic species definition”, P Natl Acad SciUSA 106: 19126-19131; and Chan et al., 2012, “Defining bacterial species in the genomic era:insights from the genus Acinetobacter”, Bmc. Microbiol.12)).The ANI of the shared genes between two strains is known to be a robust means to comparegenetic relatedness among strains, and that ANI values of about 95% correspond to the 70% DNA-DNA hybridization standard for defining a species. See, e.g., Konstantinidis andTiedje, Proc Natl Acad Sci USA, 102(7):2567-72 (2005); and Goris et al., Int Syst EvolMicrobiol.57(Pt 1):81-91 (2007). The ANI between two bacterial genomes is calculated frompair-wise comparisons of all sequences shared between any two strains and can be determined, for example, using any of a number of publicly available ANI tools, including butnot limited to OrthoANI with usearch (Yoon et al. Antonie van Leeuwenhoek 110:1281-1286(2017)); ANI Calculator, JSpecies (Richter and Rossello-Mora, Proc Natl Acad SciUSA 106:19126-19131 (2009)); and JSpeciesWS (Richter et al., Bioinformatics 32:929-931(2016)). Other methods for determining the ANI of two genomes are known in the art. See,e.g., Konstantinidis, K. T. and Tiedje, J. M., Proc. Natl. Acad. Sci. U.S.A., 102: 2567-2572(2005); and Varghese et al., Nucleic Acids Research, 43(14):6761-6771 (2015). In a particularembodiment, the ANI between two bacterial genomes can be determined, for example, by averaging the nucleotide identity of orthologous genes identified as bidirectional best hits (BBHs). Protein-coding genes of a first genome (Genome A) and second genome (Genome B) are compared at the nucleotide level using a similarity search tool, for example, NSimScan(Novichkov et al., Bioinformatics 32(15): 2380-23811 (2016)). The results are then filtered toretain only the BBHs that display at least 70% sequence identity over at least 70% of the length of the shorter sequence in each BBH pair. The ANI of Genome A to Genome B is defined as the sum of the percent identity times the alignment length for all BBHs, divided by the sum of the lengths of the BBH genes. These and ANI determination techniques are known in the art.According to the present invention, the B. longum transitional microorganism CNCM I-5942represents the reference genome to which a microbial genome is compared.In some embodiments, the B. longum transitional microorganism for use in the presentinvention is isolated from a human.In some other embodiments, the B. longum transitional microorganism is not of the subspeciesB. longum subsp. longum or B. longum subsp. infantis.Suitably, the B. longum transitional microorganism is provided as a probiotic. Suitably, the B.longum transitional microorganism is provided in a composition.The composition or combination according to the invention may contain from 103to 1012cfuof the B. longum transitional microorganism, more preferably between 107 and 1012 cfu suchas between 108 and 1010 cfu of the B. longum transitional microorganism per g of compositionor combination on a dry weight basis. Suitably, the B. longum transitional microorganism isadministered to the subject in an amount of at least about 106cfu / day, at least about 107cfu / day, or at least about 108 cfu / day. Suitably, the B. longum transitional microorganism isadministered to the subject in an amount of about 1012cfu / day or less, about 1011cfu / day or less, or about 1010cfu / day or less.In one embodiment, the B. longum transitional microorganism is viable.Antibiotic resistanceSuitably, the present B. longum transitional strain does not harbor transferable antibioticresistance to one or more antibiotics, preferably one or more European Food Standard Agency (EFSA) relevant antibiotics (see European Food Safety Authority. 2012. Guidance on the assessment of bacterial susceptibility to antimicrobials of human and veterinary importance. EFSA J 10:2740). Antibiotic resistance refers to the ability of microorganisms to withstand antibiotic treatments. The overuse or misuse of antibiotics has been linked to the emergence and spread of microorganisms which are resistant to them, rendering treatment ineffective and posing a serious risk to public health. In addition, the wide-spread use of antibiotics means that it is increasingly challenging to provide bacterial strains that do not have transferrable resistance to one or more EFSA relevant antibiotics. It is known that a single gene may instill antibiotic resistance against a particular antibiotic, and that bacteria can transfer genes through horizontal gene transfer via conjugation, transduction or transformation. Accordingly, it is known that antibiotic resistance may be transferred between bacteria via horizontal gene transfer; including in the gut microbiome.It is therefore advantageous that the present B. longum transitional strain does not harbortransferrable antibiotic resistance to one or more antibiotics as this reduces the risk of the antibiotic resistance being transferred to other components of the microbiome when thepresent B. longum transitional strain is used as a probiotic.Antibiotics resistance has been well-described and antibiotic resistance may be determined using any suitable assay known in the art. By way of example, phenotypic and / or genetic methods may be used. Phenotypic methods typically involve measuring the growth of a test bacteria in the presence of a suitable concentration of the antibiotic under consideration. In addition, a number of genes mediating antibiotic resistance are known. Accordingly, genetic methods for determining antibiotic resistance comprise determining the presence of one or more antibiotic resistance genes in the genome of the test bacteria (for example by PCR, DNA microarray, whole-genome sequencing and metagenomics, and matrix-assisted laser desorption ionization-time of flight mass spectrometry). Suitably, phenotypic antibiotic testing of may be performed according to the recommendations made by EFSA (EFSA J 16, e05206, doi:10.2903 / j.efsa.2018.5206 (2018)); for example following the official method ISO 10932.An illustrative method for determining antibiotic resistance is detailed in the present Examples.Antibiotic resistance and underlying genes present in Bifidobacterium are known in the art (see e.g. Duranti et al.; Appl Environ Microbiol.2017 Feb 1; 83(3): e02894-16.). As such, the skilled person is able to determine whether a test Bifidobacterium is resistant to one or more antibiotics.Suitably, the present B. longum transitional strain is not resistant to at least 1, at least 2, atleast 3, at least 4, at least 5, at least 6, or at least 7 EFSA relevant antibiotics.Suitably, the B. longum transitional strain is not resistant to any one of tetracycline anderythromycin. Suitably, the B. longum transitional strain is not resistant to any one of tetracycline, erythromycin, clindamycin and ampicillin. Suitably, the B. longum transitional strain is not resistant to any of tetracycline, erythromycin, clindamycin, ampicillin, gentamycin, streptomycin, chloramphenicol and vancomycin.Resistance to tetracycline may be afforded by tet(W) or tet(Q) genes which encode ribosomalprotection proteins. Suitably, the present B. Longum transitional strain may lack a tet(W) gene.Suitably, the present B. longum transitional strain may lack a tet(W) gene encoding apolypeptide shown as SEQ ID NO: 1 or a variant which shares at least 80% sequence identity to SEQ ID NO: 1. Suitably, the variant may share at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity with SEQ ID NO: 1. SEQ ID NO: 1 MKIINIGILAHVDAGKTTLTESLLYASGAISEPGSVEKGTTRTDTMLLERQRGITIQAAVTSFQWHRCKVNIVDT PGHMDFLAEVYRSLAVLDGAILVISAKDGVQAQTRILFHALRKMNIPTVIFINKIDQAGVDLQSVVQSVRDKLSA DIIIKQTVSLSPEIVLEENTDIEAWDAVIENNDKLLEKYIAGEPISREKLVREEQRRVQDASLFPVYYGSAKKGL GIQPLMDAVTGLFQPIGEQGSAALCGSVFKVEYTDCGQRRVYLRLYSGTLRLRDTVALAGREKLKITEMRIPSKG EIVRTDTAYPGEIVILPSDSVRLNDVLGDPTRLPRKRWREDPLPMLRTSIAPKTAAQRERLLDALTQLADTDPLL RCEVDSITHEIILSFLGRVQLEVVSALLSEKYKLETVVKEPTVIYMERPLKAASHTIHIEVPPNPFWASIGLSVT PLPLGSGVQYKSRVSLGYLNQSFQNAVRDGIRYGLEQGLFGWNVTDCKICFEYGLYYSPVSTPADFRSLAPIVLE QALKESGTQLLEPYLSFTLYAPREYLSRAYHDAPKYCATIETVQVKKDEVVFTGEIPARCIQAYRTDLAFYTNGQ SVCLTELKGYQAAVGKPVIQPRRPNSRLDKVRHMFSKITSuitably, the present B. Longum transitional strain may lack a tet(Q) gene. Suitably, thepresent B. longum transitional strain may lack a tet(Q) gene encoding a polypeptide shown asSEQ ID NO: 2 or a variant which shares at least 80% sequence identity to SEQ ID NO: 2. Suitably, the variant may share at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity with SEQ ID NO: 2. SEQ ID NO: 2 MRFDNASNVVYYCLIQMNIINLGILAHIDAGKTSVTENLLFASGATEKCGRVDNGDTITDSMDIEKRRGITVRAS TTSIIWNGVKCNIIDTPGHMDFIAEVERTFKMLDGAVLILSAKEGIQAQTKLLFNTLQKLQIPTIIFINKIDRAG VNLERLYLDIKTNLSQDVLCMQTVVDGSVYPVCSQTYIKEEYKEFVCDHDDNILERYLADSEIPPTDYWNTIIAL VAKAKVYPVLHGSAMFNIGINELMDAITSFILPPASVSDRLSAYLYKIEHDPKGHKRSFLKIIDGSLRLRDVVRI NDSEKSIKIKNLKTIYQGREINVDEVGANDIAIVEDMEDFRIGDYLGAEPCLIQGLSHQHPALKSSVRPDKPEER SKVISALNTLWIEDPSLSFSINSYSDELEISLYGLTQKEIIQTLLEERFSVKVHFDEIKTIYKERPIKKVNKIIQ IEVPPNPYWATIGLTLEPLPLGAGLQIESDISYGYLNHSFQNAVFEGIRMSCQSGLHGWEVTDLKVTFTQAEYYS PVSTPADFRQLTPYVFRLALQQSGVDILEPMLYFELQIPQEASSKAITDLQKMMSEIEDISCNNEWCHIKGKVPL NTSKDYASEVSSYTKGLGIFMVKPCGYQITKDGYSDNIRMNEKDKLLFMFQKSMSLK Resistance to erythromycin may be afforded by the erm(49) gene which encodes a rRNAmethylase. Suitably, the present B. Longum transitional strain may lack a erm(49) gene.Suitably, the present B. Longum transitional strain may lack of erm(49) gene encoding apolypeptide shown in SEQ ID NO: 3or a variant which shares at least 80% sequence identity to SEQ ID NO: 3. Suitably, the variant may share at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity with SEQ ID NO: 3. SEQ ID NO: 3 MRNIKDTQNFLHSKELVRHLIGICNIKLDDVVIEIGPGKGIITNELAHKARKVVAIEFDEELYEKLKNKFQSNNK VDIIYGDILNYTPRIPSYCVFSNIPFNITSEILNKFLSDKKNEKMFLIMQYEPFIKYAGNPYGAETLRSMLYKPF FDMDLKYRFDPSDFKPAPQARIVLASFERKQFPDVKKEEEKLYKDFLAYIYTNKGETFFAKIKTLFSSNQIKRVW GQIKIDKTTKISEVPYESILKVFKLFFLYGTDANKQLVVNSFNNMNKQNNKLQKNHRNNSKAKSWNSNRKRKPYH RNNV Resistance to erythromycin and clindamycin may be afforded by the erm(X) gene whichencodes a ribosomal protection protein. Suitably, the present B. Longum transitional strainmay lack an erm(X) gene. Suitably, the present B. Longum transitional strain may lack anerm(X) gene which encodes a protein comprising SEQ ID NO: 4 or a variant which shares at least 80% sequence identity to SEQ ID NO: 4. Suitably, the variant may share at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity with SEQ ID NO: 4. SEQ ID NO: 4 MSAYGHGRHENGQNFLTNHKIINSIIDLVKQTSGPIIEIGPGSGALTHPMAHLGRAITAVEVDAKLAAKLTQETS SAAVEVVHDDFLNFRLPATPCVIVGNIPFHLTTAILRKLLHAPAWTDAVLLMQWEVARRRAGVGASTMMTAQWSP WFTFHLGSRVPRTAFRPQPNVDGGILVIRRVGDPKIPIEQRKAFQAMVHTVFTARGRGIGEILRRAGLFSSRSET QSWLRSRGIDPATLPPRLHTNDWIDLFQVTGSSLPHHRPISPSGSSQRPPQQKNRSRRR Resistance to streptomycin may be afforded by a mutation within the rpSL gene which encodes a ribosomal S12 protein. More specifically, a mutation at nucleotide position 128, replacing an A residue to a G residue was shown to provide streptomycin resistance (seeKiwaki & Sato; Int J Food Microbiol. 2009 Sep 15;134(3):211-5). Suitably, the present B.Longum transitional strain may have an A residue a position 128 of the rpSL gene. Suitably,the present B. Longum transitional strain does not comprise a G128A mutation in the rpSL gene. An illustrative rpSL gene sequence comprising an A at position 128 is shown as SEQ ID NO: 5. SEQ ID NO: 5 TTGCCTACTATTGAACAGCTCGTCCGTAAGGGACGTCAGGCAAAGCCGAAGAAGTCCAAGACTTTGGCCCTGAAG GGCAGCCCGCTGCGTCGCGGCGTGTGCACCCGTGTCTACACCACCACCCCGAAGAAGCCGAACTCGGCTCTGCGT AAGGTCGCTCGTGTGCGCCTGTCCTCGGGCATCGAAGTCACCGCCTACATTCCGGGCGAGGGCCACAACCTGCAG GAGCACTCCATCGTGCTCGTGCGCGGCGGCCGTGTGAAGGATCTCCCGGGTGTGCGTTACCACATCGTGCGTGGC GCGCTCGATACCCAGGGTGTCAAGGACCGTAAGCAGGGTCGTTCCCTGTATGGAGCAAAGAAGGCGAAGTAA Resistance to chloramphenicol may be afforded by the crmX gene which encodes a ribosomalprotection protein. Suitably, the present B. longum transitional strain may lack a crmX gene.Suitably, the present B. longum transitional strain may lack a crmX gene encoding apolypeptide comprising SEQ ID NO: 6 or a variant which shares at least 80% sequence identity to SEQ ID NO: 6. Suitably, the variant may share at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity with SEQ ID NO: 6. SEQ ID NO: 6 MPFALYMLALAVFVMGTSEFMLAGLLPAIATELDVSVGTAGLLTSAFAVGMVVGAPVMAAFARRWPPRLTLIVCL LVFAGSHVIGAMTPVFSLLLITRVLSALANAGFLAVALSTATTLVPANQKGRALSILLSGTTIATVVGVPAGALL STALGWRTTFWAIAILCIPAAVGVIRGVTNNVGRSETSATSPRLRVELSQLATPRLILAMALGALNNGGTFAAFT FLAPIVTETAGLAEAWVSVALVMFGIGSFLGVTIAGRLSDQRPGLVLAVGGPLLLTGWIVLAVVASHPVALIVLV LVQGFLSFGVGSTLITRVLYAASGAPTMGGSYATAALNIGAAAGPVLGALGLATGLGLLAPVWVASVLTAIALVI MLLTRRALTKTAAEAN Glycan Substrate / Carbohydrate-Active Enzymes (CAZymes)The present B. longum transitional strain encodes a specific profile of Carbohydrate-ActiveEnzymes (CAZymes). Carbohydrate-active enzymes (CAZymes) are responsible for the synthesis and breakdownof glycoconjugates, oligo- and polysaccharides. They typically correspond to 1-5% of thegenes in the living organism. Glycoconjugates, oligo- and polysaccharides play essential rolesin many biological functions, for example as structure and energy reserve components and inmany intra- and intercellular events. The Carbohydrate Active Enzyme (CAZy) classificationis a sequence-based family classification system that correlates with the structure and molecular mechanism of CAZymes (www.cazy.org). CAZymes include glycoside hydrolyases (GH), glycosyltransferases (GT), polysaccharide lyases (PL), carbohydrate esterases (CE), and carbohydrate-binding module families (CBM) GHs catalyze the hydrolysis of glycosidic bonds between two or more carbohydrates or between a carbohydrate and a non-carbohydrate moiety. In most cases, the hydrolysis of the glycosidic bond is catalyzed by two amino acid residues of the enzyme: a general acid (proton donor) and a nucleophile / base. Depending on the spatial position of these catalytic residues, hydrolysis occurs via overall retention or overall inversion of the anomeric configuration. A GH classification system is provided by the CAZy classification. Herein, GHs are divided into families based on molecular function (e.g., GH1, GH2, GH3, GH4, etc.). These families are then further divided into subfamilies based on subgroups found within a family that share a more recent ancestor and, typically more uniform in molecular function (e.g., GH13_1, GH13_2, GH13_3, GH13_4, etc.).Suitably, the present B. Longum transitional strain encodes a glycosyl hydrolase family 43_17(GH43_17) enzyme. GH43_17 comprises both α-L-arabinofuranosidase (EC 3.2.1.55) and endo-β-1,4-xylanase (EC 3.2.1.8) activities, with capacity to breakdown complex carbohydrates like arabinan, arabinogalactan, and arabinoxylan. Suitably, the GH43_17 gene comprises SEQ ID NO: 7 or a sequence with at least 60% sequence identity to SEQ ID NO:7. Suitably, the GH43_17 gene comprises a sequence with at least 60%, at least 70%, at least80%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 7. SEQ ID NO: 7 ATGAAACGAACTGACATCCACCTGCGCGATCCGTTCGTCCTGCCTCACGACGGTGTCTATTACCTGTATGGCACC CGCGCTGATAACGTGTGGGGCGCGATGGATGGTTTTGATTGCTACACCAGCCGCGACCTTGACAATTGGGAGGGT CCGTTCGAGGTGTTCCACAAGCCGGATGAATTCACGGCCGACCGTGCTTACTGGGCGCCCGAATGCTACGAGCGA GACGGTGTATTCCACCTGATTGCCACGCTCGGCGAGCCGGACGGGCGCAAAAGCGTGCACATGCTACGCGCTGAT AGTCCGCTTGATCCGTTCGAATATGTCTGCCGGCTGACCGATCCGAATCAGTCCTGCATTGACGGAACTCTGCAT GGTGAAGGTACCGATATGTGGCTTGTCTACTCGCATTCCTTGGAGGATGTGCCCGCCGGAGACATGGATGCCGTA CGTCTGTCCTCCGACCTGACTCGGACGGTGGGGGAGAGCATGACATTGTTCCAGGCCTCGGATGCGCCGTGGGCG GTGCCGGTGCCGTTCGCGAAAGCGGAATTCGGCATCGACGAGGACGCCTACTTCTCCGATGGTCCCTGCCTGTGC AGGCTTTCCAACGGACGGCTGGCGATGCTGTGGTCGAGCTGGTCGACGGAAGGCGGATATGCAGTCGGCCAGGCC ATCAGCGAATCAGGGTCGATTGCTGGGCCTTGGACGCAATGCCCCGAGCCTCTGCTTAGCCACGGCGGCCACGGC ATGCTGTTCAACGGTCTCGATGGCGTGCTGCGTTACGCGGTCCACTCGCCCAACGACCCCGGCCAGGAACGGCCT ACGTTTTTGTGCGTCGAAGAACAAGACGGGCTGCTGACGATTACGGAATAG Suitably, the GH43_17 gene may encode a protein shown as SEQ ID NO: 8 or a sequence with at least 80% sequence identity to SEQ ID NO: 8. Suitably, the protein may comprise a sequence with at least 85%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 8. SEQ ID NO: 8 MKRTDIHLRDPFVLPHDGVYYLYGTRADNVWGAMDGFDCYTSRDLDNWEGPFEVFHKPDEFTADRAYWAPECYER DGVFHLIATLGEPDGRKSVHMLRADSPLDPFEYVCRLTDPNQSCIDGTLHGEGTDMWLVYSHSLEDVPAGDMDAV RLSSDLTRTVGESMTLFQASDAPWAVPVPFAKAEFGIDEDAYFSDGPCLCRLSNGRLAMLWSSWSTEGGYAVGQA ISESGSIAGPWTQCPEPLLSHGGHGMLFNGLDGVLRYAVHSPNDPGQERPTFLCVEEQDGLLTITESuitably, the present B. Longum transitional strain comprises a glycosyl hydrolase family43_22 (GH43_22) gene. Suitably, the GH43_22 gene comprises SEQ ID NO: 9 and / or 10, or a sequence with at least 60% sequence identity to SEQ ID NO: 9 or 10. Preferably, the presentB. Longum transitional strain comprises a GH43_22 gene with at least 60% sequence identityto SEQ ID NO: 9 and a GH43_22 gene with at least 60% sequence identity to SEQ ID NO: 10. Suitably, the GH43_22 gene comprises a sequence with at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 9 or 10. SEQ ID NO: 9 GTGAAGCATTGGAAGAAGATGGCAGCATCGTTGGTTGCAATATCAACGATGATGGCAGTAGTTCCGACGACGTAT GCCATGGAATCGGAAGATTCCCAACCACAGACAACCGATACCGCGACAGTGCAGACTACTAAGGCTGCTGAACCG ACGCTGCTCGCCAGCTGGGACTTCACGGGCAAAAACGGCACCACGAACAGCGCGATTGCCGATTCGACCGGCAAG TACAACCTGACGCTGAAGGACGGCGCCAAGATCGAACAGTACGGTGACCGCAGCACCAACGAGGCGCTCTCACTG CGCGGCGATGGCCAGTACGCCCAGATCGATGACCAGCTGTTCAAGGATGCGGGCGACTCCTTCACTCTGGAGTTC GCGTCCAAGACTCGTCACGACGACAGCGGCAAGTTCTTCTCGTTCATCGTCGGCAAGGACGGCTCGAACGACGCC AACACCACCGATCAGGCCAACGCCAACAAGTACCTGATGTTCTACAACAGCAAGACCGCCATCAAGGGCGTTATC TCAAACAACAACTGGGGTAACGAACAGGGATCCAAGGTCACCGTTTCCGGCAACGACAACAGCTGGGCCGATTAC AAGATTGTCGTGGACGGCACCAACCTTGCCGTGTTCCGCAACAATGCCCTGATTATTTTCAAGGCCAACACCGGC ATCAAGATGAGCGATCTCGGTGCGACCACCGCCTACATCGGCAAGTCGTTCTACTCCGTCGATGAGTACTGGAAT GGTGCAATGGATGATATCAAGGTCTACAGGGGCGCTGACCTGACCATGCCGACCGCCGTTGCGATTTCCGGTACC GGTGTGGTGAACAACAAGCTCACCCTGATTGAGAAGGACTCCACCAAGCTCACCGCCACCGTCACTCCGGACGAC GCCGTGAGCAAGAACGTCACCTGGTCCTCCTCCGATGAGTCCGTGGCCAAGGTCGCCGCAGACGGTACTGTAACC GGCGTCAAGGCTGGTACTGCCACCATCACCGCCACCACTGAGCTGGGTGGTGTGAAGGCCGAACTGCCCGTCACC GTTGAGCCGATGAACGCCCAGAACGCCGCCGCAGCCGACCTCGATGCCGCGATTGCTGCGCTGAAAGTTCCGGCG GCCGAGAATCTGCCGCTAGTCGCCAAGGGCACCAAGAACGGCTCGGCGATTACGTGGAAGTCCTCGGACGAGAAG CTCATTACGTCCACTAACGAGAAGTACGAAAACAAGACCACTGGTGCCGATGACCCGTATCGTGGTGCTGGCATC ATCAATCGTCCGGCCTACGGCGACGGTGATTCCAAGCCGGTTACGCTGACCGCCACCGCTTCCTACAACGGCGGT GAGAAGGTCACCAAGACCATCGAGGTCACTGTCAAGGAGAAGACCCGCATCGCGCCTGACACCGGCTATGCGGCC GTCACTTTTGAGAGCGACAGCAACGGTGGAGAAAAGGCCTGGGTGGCTTCCACTGAGAAGAACGATTTCTTCACG TTTAAGACTCGCAACAATGGCCAGGCGGTACTTACCAATGATGCAGACACGGGTGGCTTGCGTGACATGTTCGTG CTGCGTTCCCACGAAGGCGACAAGTACTACCTGATTGCCACTGATCTCAAGGTCTCGTCAATGGGCTGGAGCCAG AACCAGGTTAACGGTTCTCGGAAAGTTGAGGTCTACGAGTCCACCGATATGATGAACTGGACCCGTACCAACGGC GACGGCAACGGCGGCATCACCATCAACACGCCGAACGCCGGTATGACCTGGGCGCCGGAAGCTTACTGGGATGAT GACCTGAACGCTTACGTGGTGTTCTTCTCTTCCCGCATGTTCACTGATGACACCCGTACCACTCCGGTCAAGAAC GACAAAACCGGCAATAGCTCCTATGCTCAGGTGCGTTACGCCATCACCCGCGACTTCGTGAACTTCACCGAGCCG CAGATGTGGCAGGACACCGGCTACTCGCGCATTGATTCCACCGTGCGTAAGATCGGTGGCTACTACTACCGATTC ACCAAGAATGAGCAGGGCGGTGCCGCTGGCGATTACATCACCACTGGTAAGAGCATCTTCCTTGAGCGTTCCAAG GTGCTGACTGCACCGACCACCGAGGCATCTCCGGGTCAGGACCCGAACACCGGTTGGCAGTGCTCGAGCAGGCGT TGCTGCCGTTCGAAGGACCAGAGACCATCAAGCTCAACAAGGATGACGAACTCAACACGAAGGACGACGACGGCT ACATTCTGCTGTCCGACAACTTCGCCTACCGTGCATTTATGACCACGGGTGCCGAGCTTTCCAAGACCACGTGGG ACAACCCGATGACCAAGCGTTACCCGGACTTCAACAACGAAAAGAAGCCGGTCAAAGCCGAGCCGGGCGCTCAGG GCTACATCACTCAGGGTGCTAACGGCGGTCTGCCGGACAAGGTGCGTCACGGTGCGTTCGTGAACGTGCCTGAGT CTGTGCTCAAGGTGACGAAGTCCTGGACCGCTGCCAACCCGACGCACATCGAGGCTGTTGACTCCACCACCAAGG CCGTGTACAACGCCGGCACCCGCGAGCTCACCGCCACGGTGACCGCCGCCGATAAGGGCACGCTCGCCGGTTCGG TGAAGTTCTCTGCTGGCGACTGGTCCAAGACCGTGAAGCTCGACGCCGAAGGCAAGGCCACTGTGACCCTCCCGG CCAGCGTCTCTGGCACTGTTGCGGTTGCTTACGACGGCTACACCGATGGTTTGGTCAATCCATCCGATACTACGG TTGACGGCATTGAACAGGGCAAGGTCGATTTGGCTGAGCTCAACAAGCAGATCGCTGCCGCCGAAGCGCTCAAGG AATCCGACTACACGGCCGATTCCTGGGCCAAGCTTGCCGCCGCGCTGAAGACTGCCAAGGCCGCGCTCGCCGCTG AGAATCAGGGCGAGGTCGATACCGCCGCAGCCGACCTTAAGACCGCAATCGAAGCCCTGCAGAAGGCTCCGACCA ATCCGGGCGAAGGTGACGGAGATAAGGGCGACGGCAATAAGCCGACTACCCCGACCACCGGCGACAAGACCAACG TCAACAAGCCCGGCAGCGCGCTGAGCAATACCGGTACGGCCGTGCTCGGCCTGGGTGGTGCCGTGGTAGTACTCG CCATCGCCGGCATCTCCCTAACCCTCTGGCGCAAGCGTCGCGCCTGA SEQ ID NO: 10 ATGGGAAAGCTGATACGAAAGGCAACCGGACTCACGGTCGGCGTGGCAACACTGCTCGCTGGTCTGGTGCTGCCG ATGACGGCCAGTGCCGAGAGCGCATCGCCAATCGATGCCAGTCCGATCATCCACTATTCATTCGATAACGCACTG ACGTCCAAGACCATCGCCAACGAGGGCAGCGCGGCCAACAGCGATGCCACCCTATCCGGCGACGCCACGGTGGCC AATGGCCAGATCAACCTGACCGGCTCGCAAACCATTAGCGTGCCGACCACGGCCATCGCCGGTAAGAAGGACGTC ACCGTCTCCATCTGGCTCAAGAACAATTACGGCAACGGCAATACCGCCGCCGCGTACATCGGCGCGGCCAAGACC GGCAATTATCCGGCCAACGGTTACTGGCTGCTCAACCCGGCCAACCCGAGTGGCTACGCGAAATCCGTAATGACC AATGCCACTGCGGCCGACCCGAATAACAGCCCGTGGGGCACCGAAGTCGGCCCTGGATCGACGAACGCCGCCATC ACCGGCACCAAGGCCACCAGCGATTTGGCTCTGTACACCACCGTCATCAACGGCACCAACAGCACTATGAGCTTC TACCTCAACGGCAAGCAGGTTGGAGACGCCACCTACGCCATTCCGGCCGGTGGCCTGACCAATTACGGCGATCTC GTCGCCTACATTGGCAAGTCCTCCTACGCTGACCCGAACTCCAAGCTCGACGTGGACGATTACGCCGTATACGAC ACTGCCATCAGCGCCGCAGACGTGACCAAGCTGTATGACGTTCAGGTGCTCGACAAGGCCGAGGCCGCTGTCAAG GCCGCTGTGCCCGCATCCGCTACCGAGGACTTCACCCTGCCGACCAGCGCCGCTGGTGTGAGCGTCGCGTGGAAG TCGGACAACGCAGCCATCGCCGTTGACAACGCCACCGGCAAGGCCACGGTCACTCGTCCGGCCGCAACCGCAGCT GATGCCGAGGTGACCCTCACCGTCACGTTCGGCAACAACGCCAAAACCGCCGCCTACACGGTCCTCGTGCCGAAG CAGCTCTCCGATGCCGAGCAAGCCAAGGCCGACCTTGACGCCATCACCATCGAGGACTCCGACGACATCCGTAGC AACTTCTCCGTGCCCACCAAGGGCAACAATGGTTCGACCATCTCGTGGGGAGTGACCGGTGGCAAGGATATCGCC ACACTAGGCGAAGGCGTGAGCGACAAATCTCGAACGGTCACTGTTAAGCGCCCTGCCGCCGGTAGCGATGCCGCC ACTGTGACGCTCAAAGCCACTGCCAAGTACGATACCGCCACTGAAACTAAGACCTTCACCGTCACCATTCAGCCG ATGCCTGCCGCCGAAGAGAAGGACGAGGCCTACGTGTGGGCGTTCTTCACCGGCGAGGGCGTGGGCGGCGAGAAA ATCAGCCTCGCGGCCTCCAAGGGCAACGATGCGCTCGACTGGAACACGCTGAACAACGGCACGCCGATATTCACT TCCGAGTTTGGCGAGAAGGGTTTGCGCGATCCGTTCATCATGAAGTCCAAGGACGGCGACAAGTTCTACATGCTC GCCACCGATCTGAAGATTGACGGTCGTGCCCCCCTCAACGGGCTGAATGGCTTTGCTGGTGCACAGGCTAACGGT TCCAAGTACATTGAGATCTGGAAGTCCGACGATCTGGTCAACTGGTCCAAGCAAAGCCACGTCAAAGTGAGCTCT GATTACGCAGGCAACACTTGGGCGCCTGAGGCCTACTACGACGAGGAAATCGGCAAGTACGTGGTCTATTGGGCC TCGAACCTGTACGACAACACCGACGAGAACAGCCGCAAGCAGCTGACCTACAACCGCATGGTGTACGTCACCACC GATGACTTCGTCAACTTCTCCGACCCGACAGTGTGGATTGACGTTGATCGCCGAGGCGGTGCAGGCAGTGGATCC ATCGATGTGACCGTGCAAAAGGTAGGGGATACCTACTACCGCATCTACAAAGATGAAAACACGATGTCTTTGCGT CAGGAGAAGTCCACAGATTTGACTGCCGCAATTGGTGGTGCCGGCGTGAAGAACTACGCCGATGCGCTTAAGGGT AGTGCATGGAGCGAAGTTGCCACGAACATCGGTAAAGGCCAGGCTAACGGTTACGGTAAAACCTTCACTTCCGGC GAAGGTCCATCGCTATTCAAGGCCAACGATGGCGATGTGAACGGCTACCAGTACTACCTGTTCGCCGACCAGCCG AGCTATCATCAAGGTCCAAACCACTATGTGCCGATGGCGACTGAGGATATCGCCAGCGGTCAGTGGACCGTTATC GGCAATAAGATGCCTGAGGCGAACTTCCCGACCAACTCCGATGGCGGCAAGCCGCGCCACGGAACCGTGCTGCCC GTGACCCGCGCCCAGTACCAGAAGGTGCTGGAGGCATACGCCCCGGCTGTGGCTGTGAAGTCCGTTGACGCGCTG TCTGCCGAGACAACGGTTGGTGTGGCTCCGACGCTGCCGGAGACCGCGCATCTGACTCATGCGGACGGTTCCGTT TCTGACGTTGCAGTTGAGTGGGATGCCATTGACGCATCTTTCTACGCCAAGACCGGCACCTTCACCGTCAAGGGC ATCACCCAAGACGATTCCCGTATGCCGGTTGAGGCTACCGTCATTGTGAACGGCATCGACCTCTCCAAGGCGACC GTCACCGTCGAACCCAACGAGTTCACCGCAGACGGCGCTGCCAAGGAACCAGCCGTGACCGTTGTACTCGATGGC GCGACGCTCAAGGAAGGCGCCGACTATACGGTGGCCTATACGAACAACGTCGAACCTGGCACTGCCACAGTGACC GTAACCGGCGCTGGCAAGTACTCCGGTACTGTCTCGGCAACGTTCACCATCAAGGCCGCCGAGCCCGGCTCCACG CTGGACAAGTCCAAGTTGCAGGCGCTTGTCGATAAGGTGAAGGGCTATAACAAGGCTGATTACCAGTCTGGTTGG GATGCTTTCGCCGTCGCGCTCGCCGACGCGCAGCAGGTGTTGCAGAACTCCACCGACCAGCAGGAAGTGGACAAG GCGTTGTCTCGGCTCCAGTCCGCCGTCGACAAGCTGGTCAAGAAGTCCGGCGATTCCGGCAAGACCGATGGCAAG GATGACGGCACGCAAAAGCCCGCCGCCAAGCCGGGCAGCGCTCTGTCCAACACCGGCGCCTCGGTGTTCGGTGTG GGTATCACCGCGGTCATACTGCTCGCCGCCGCCGGCGCCGCCTACGCCTTCCGCAAGCGCCGCGCCTGA Suitably, the GH43_22 gene may encode a protein shown as SEQ ID NO: 11 or 12, or a sequence with at least 80% sequence identity to SEQ ID NO: 11 or 12. Preferably, the B.Longum transitional strain comprises a GH43_22 gene encoding a protein shown as SEQ IDNO: 11 or a sequence with at least 80% sequence identity to SEQ ID NO: 11m and a GH43_22 gene encoding a protein shown as SEQ ID NO: 12, or a sequence with at least 80% sequenceidentity to SEQ ID NO: 12. Suitably, the protein may comprise a sequence with at least 85%,at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 11 or 12 SEQ ID NO: 11 MKHWKKMAASLVAISTMMAVVPTTYAMESEDSQPQTTDTATVQTTKAAEPTLLASWDFTGKNGTTNSAIADSTGK YNLTLKDGAKIEQYGDRSTNEALSLRGDGQYAQIDDQLFKDAGDSFTLEFASKTRHDDSGKFFSFIVGKDGSNDA NTTDQANANKYLMFYNSKTAIKGVISNNNWGNEQGSKVTVSGNDNSWADYKIVVDGTNLAVFRNNALIIFKANTG IKMSDLGATTAYIGKSFYSVDEYWNGAMDDIKVYRGADLTMPTAVAISGTGVVNNKLTLIEKDSTKLTATVTPDD AVSKNVTWSSSDESVAKVAADGTVTGVKAGTATITATTELGGVKAELPVTVEPMNAQNAAAADLDAAIAALKVPA AENLPLVAKGTKNGSAITWKSSDEKLITSTNEKYENKTTGADDPYRGAGIINRPAYGDGDSKPVTLTATASYNGG EKVTKTIEVTVKEKTRIAPDTGYAAVTFESDSNGGEKAWVASTEKNDFFTFKTRNNGQAVLTNDADTGGLRDMFV LRSHEGDKYYLIATDLKVSSMGWSQNQVNGSRKVEVYESTDMMNWTRTNGDGNGGITINTPNAGMTWAPEAYWDD DLNAYVVFFSSRMFTDDTRTTPVKNDKTGNSSYAQVRYAITRDFVNFTEPQMWQDTGYSRIDSTVRKIGGYYYRF TKNEQGGAAGDYITTGKSIFLERSKVLTAPTTEASPGQDPNTGWQLLEQALLPFEGPETIKLNKDDELNTKDDDG YILLSDNFAYRAFMTTGAELSKTTWDNPMTKRYPDFNNEKKPVKAEPGAQGYITQGANGGLPDKVRHGAFVNVPE SVLKVTKSWTAANPTHIEAVDSTTKAVYNAGTRELTATVTAADKGTLAGSVKFSAGDWSKTVKLDAEGKATVTLP ASVSGTVAVAYDGYTDGLVNPSDTTVDGIEQGKVDLAELNKQIAAAEALKESDYTADSWAKLAAALKTAKAALAA ENQGEVDTAAADLKTAIEALQKAPTNPGEGDGDKGDGNKPTTPTTGDKTNVNKPGSALSNTGTAVLGLGGAVVVL AIAGISLTLWRKRRA SEQ ID NO: 12 MGKLIRKATGLTVGVATLLAGLVLPMTASAESASPIDASPIIHYSFDNALTSKTIANEGSAANSDATLSGDATVA NGQINLTGSQTISVPTTAIAGKKDVTVSIWLKNNYGNGNTAAAYIGAAKTGNYPANGYWLLNPANPSGYAKSVMT NATAADPNNSPWGTEVGPGSTNAAITGTKATSDLALYTTVINGTNSTMSFYLNGKQVGDATYAIPAGGLTNYGDL VAYIGKSSYADPNSKLDVDDYAVYDTAISAADVTKLYDVQVLDKAEAAVKAAVPASATEDFTLPTSAAGVSVAWK SDNAAIAVDNATGKATVTRPAATAADAEVTLTVTFGNNAKTAAYTVLVPKQLSDAEQAKADLDAITIEDSDDIRS NFSVPTKGNNGSTISWGVTGGKDIATLGEGVSDKSRTVTVKRPAAGSDAATVTLKATAKYDTATETKTFTVTIQP MPAAEEKDEAYVWAFFTGEGVGGEKISLAASKGNDALDWNTLNNGTPIFTSEFGEKGLRDPFIMKSKDGDKFYML ATDLKIDGRAPLNGLNGFAGAQANGSKYIEIWKSDDLVNWSKQSHVKVSSDYAGNTWAPEAYYDEEIGKYVVYWA SNLYDNTDENSRKQLTYNRMVYVTTDDFVNFSDPTVWIDVDRRGGAGSGSIDVTVQKVGDTYYRIYKDENTMSLR QEKSTDLTAAIGGAGVKNYADALKGSAWSEVATNIGKGQANGYGKTFTSGEGPSLFKANDGDVNGYQYYLFADQP SYHQGPNHYVPMATEDIASGQWTVIGNKMPEANFPTNSDGGKPRHGTVLPVTRAQYQKVLEAYAPAVAVKSVDAL SAETTVGVAPTLPETAHLTHADGSVSDVAVEWDAIDASFYAKTGTFTVKGITQDDSRMPVEATVIVNGIDLSKAT VTVEPNEFTADGAAKEPAVTVVLDGATLKEGADYTVAYTNNVEPGTATVTVTGAGKYSGTVSATFTIKAAEPGST LDKSKLQALVDKVKGYNKADYQSGWDAFAVALADAQQVLQNSTDQQEVDKALSRLQSAVDKLVKKSGDSGKTDGK DDGTQKPAAKPGSALSNTGASVFGVGITAVILLAAAGAAYAFRKRRASuitably, the present B. Longum transitional strain comprises a glycosyl hydrolase family43_27 (GH43_27) gene. Suitably, the GH43_27 gene comprises SEQ ID NO: 13 or a sequence with at least 60% sequence identity to SEQ ID NO: 13. Suitably, the GH43_27 gene comprises a sequence with at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 13. SEQ ID NO: 13 ATGACAACCAAACCATCGATAGGCAAACGCCTGCTCGGCGCGATGCTGGCAGTGCCGATGGCGCTCGCCGGCATG GGAATCGGCGCGACCACGGCGGTCGCGGCCGATACCGTTCCGACCAATAATCTCATCGCCGCCTACGACTTCACC ACGAAGCCAAGTGACGGCAAGACCGTGGCCAACAGTGCGCCGAACGCTACGCTTGGCGCGGCCGAAGTACAGAAC TCCGCCGACTCGCTTTGGGCCGATGATGCCCTCACCCTTTCCGGCGGTGCCAAGACCGGCACCGGCGACTGGGTC AAGCTGCCCTCGAATCTGCTGTCCGGCAAGGACGCCGCCACGGTGCAGTTGGAGGTCAAAGCGGATTCCAGCATG CTCAATGCTTTCCATTTCCTGTGGAACATCGGTAACGACAGCTCCGATACGGAGTATTTCTTCGCCACGCTCAAC TGCGGCAGTTCGCGTAACCCGCTCGTCGGCCTGAAATCGGGCGGTACGGAGACGCTCGTGCAGTCCAGCTCCTGC GTGGCCAAGGCCGACCAATGGTTGTCGGTGACCGCCACCATTGATGGCACCGCCGCGAAACTGTACATCGACGGC ACGCAGGTGGCATCCGGCACCGTGCCGGCCAAACTGTCCAGCGTCAAGGACCAGTCGCTCAACACCATCGGCCGT TCGCCGTGGCCCGACAACCTGTTCAAGGGCGCGGTCTCGAACTTCCGCGTATACGATGCCGCGCTCACCGCCGAT CAGGTCGCCGCGATCAGCACTGCCGATGCCTCAATTCATGCCGGTGAACTCACCGGTTCCGTGCTGAACGGCATC ATCATCCCCACGACGGTCGACGATCCGTTCATTTCGCTGCCCACTGCGAACGGCGTGACGTGGGCGTCCTCCGAT AGCAGCGTCATCGCGACTGACGGCACGGTCAACCAGCCCGCCAAGGGCGAGGCAGCCAAGACTGTCACGCTGACC GCCGCCGTCACGATCCGTGGCCAGACCGCTACGAAGGAATTCACGGTCACAGTCAACCCGACCACGAAAACTGCC GCTGAACAGCTCAAGGAAGCCGCGGCCGGCTACGTGATCCCGTCCGTCGTGCGTTCCGGAGACGCCCTCCCGGCG GCTGTGAATGGCACTACCGTCACGGTTACGTCCACTAAGGACGTAGCCGTCGAGGATGGCAAGATCACCATCGAT GGCGACGAGGCCACGACCGGTACCATCACCGTCGAGTTCTCCAAGAACGGTCTCGCCGGCATCGAGCCCATTACC AAGGTCTTCACCGTAAAGGTGCTGCCCGCCGCGAAGTCCGCGACCATCGCCGCCTATGATTGCAACGCCACCAGC GCCGACGAGGCCAACAACGGCGACATCGCCTACAGCATGCACCTCGCGTTGCAGAACGCTGACGGTTCGTACACC CCGTACAACGAGAATTACGGTATCTTCTTCGCACGTTCGCCGAAGGCGCAGAATCTCAACGAGAACCTCGACGGC AATGATTACCGCAGTCTCAAGGATCCGAGCCTGCTCCGCATGGCCGACGGCACCTATGGCGTGATTTCCGTGCGT ACCAACCGCGGCACCGCCACCGGTGACTCCACCGCGAAGTCCAGCGTGCTCATCGCCACCTCCGAAGACCTGCTC ACCTATAGCGAACAGGAGAACTCCGGTTCCATCGTCGACCTTGGCGAGACCAACGGCGTCAACGCTCCGTACGCC GTGTACGACACCGCCAGCAAGCAGTATGTTGTCGGCTGGGCCGATGACAACGGCGTGGCCAAGTACACCACGTTC GATTCGCTCAAGGGCTCCGCGTCCAAGCATGGCAGCGTACTGTACGGTTCCATCGCCAAGTCCGGCGTACTCGAT GCCGACGGCGTGCAGGGCATCGCGAACTTCCGCTCCGGTGCCACCATCGCGGTGGACGAGGCGACCGTCAAGGCG CTCAACACCCGTTACGGCCGCTCTGAGAACACCGGCACGAGCAATCTCACTGACATCACCGTCGAGAAAGGTTCC TCGATTGATGAGATGACCTCGCAGCTGCCGAAGAACGTGGACCTCACTTACTCCGACGGTTCTACCGGCTCCCTG CCGATTTCCTCATGGAACACTGAGGGTATAGATCTGACGAAGGTGGGTGATTACACTGTCACCGGCACCGTCAAG CAGACCGAATACCAGATTCCGTTCGCCGAGGACCGCGCCGATCCATCGGTGTATAAGTGGCAGTGGACGCATGAG GTCGACGGCAAGGAAGTCACCGAAACCAAGTTCCTGATGATCGCTTCCAACGACATCCAAGGTGATGTCACTTGG CAGCATGGTTCGCCCCACATGCCGTTCCGCATGGCCGACACGATTTCCGGTCTCGCCGACGAGCCGGGCAACCCG AATGCCCTGATTCAGTCGAACGGCTACAACAACAAGGAGGTGTCGCTGCTCAAGGCTGGCGACAAGGACTCCGAG GGTAATGCCATCATGCACAGCTTCTGGGCTCCAGAAATTCATGAGATTGATGGTAGGCTCACGATTCTGTTCATG GCCGGATACGGCAACACATGGTCCAACGGCAAGTCGGTGTACATGCAGCTCAAGCAGGATGCCGACGGTCATGAC CTCGACCCGACCGACCCCGATAACTGGACTGTGCCGACACCGATCTACCGCAATGACGCCTCGCTGCTCAACGGT AACAAGCAGCTCGCAGCCACAGCGTCCGGCGGAGTGGGCATGTCGCTCGACATGACCTATTTCCAGGATGCCGAC GGCAGGTCCTACTACGCCTGGCAGCAGCTCGGCGCCACCTACATCGCCACGATGGATCCGAAGGACCCGGCCCAT GTGACCAGCTCCCCGGTGCGCATCGTCACCCCGGAGTATGCGTGGAACGCCGCCATAGCCGAAGGTCCGAACGTG ACCCTGCGCGACGGCAAGCTGTACCTCATGTTCTCCGGTTCCGGCGTGGGTAAGACATACACCACTGGGCTGGCC GTAGCGGATGCCTCCGGTACTGACCTGACCGACCCGGCCAGTTGGACGGTGCTCAACTACCCGATTCAGAAGTCC GGTCCGTTCAACGGTGAGATGCAGCTCGGCACCGGTCACGGCATGTGGAGCGAGGACGAAGATGGCAACCAGATC TACGTGTTCCACGCCTATGCCACGAAGAATCTCGGATCCGTGAATGCTGCCGGCCGCGACATGTTCGTGCGCCGT GTGCACTGGGCCGCCGACGGCATGCCGGTGTTCGACATGAGCTCTTCCGAGGAGCTGGCGAACAAGATCGTTTCC GTTACGGTGCATGTGGTTGACGATGCGGTTGCGGTCGATAAGTCTGGTTTGTCCAAGGCGCTTGCGTCCGCCAAG CAGCTGCACGGGTCCGACTACACCGCCGCCTCGTGGAAGGCGTTTGCCACGATGCTGGCCTCCGCTGAGAAGGTC TATGCCGACGATACTGCTACGCAGAAGGACGTCGATGACACGACCGTCGCGTTGGTCAAGGCGCAGGCTGCGTTA GTGAAGATTGATGGTTCCGATTCAGGCGATGGCTCGGGCGATTCGACTAAGCCGAGCGACGGTTCGAGCGTCGAT GCGGGAGATAAGACGTGCAACAATCTTGGTTTGTCCAAGACCGGTGCGGCTGTGCTTAGTCTTAGCGGCGTAGCC GTGGCGCTTGCTGTCGCCGGTATCGCTCTGACTCTCCAGCGCAAGCGTCGCGCCTGA Suitably, the GH43_27 gene may encode a protein shown as SEQ ID NO: 14 or a sequence with at least 80% sequence identity to SEQ ID NO: 14. Suitably, the protein may comprise a sequence with at least 85%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 14. SEQ ID NO: 14 MTTKPSIGKRLLGAMLAVPMALAGMGIGATTAVAADTVPTNNLIAAYDFTTKPSDGKTVANSAPNATLGAAEVQN SADSLWADDALTLSGGAKTGTGDWVKLPSNLLSGKDAATVQLEVKADSSMLNAFHFLWNIGNDSSDTEYFFATLN CGSSRNPLVGLKSGGTETLVQSSSCVAKADQWLSVTATIDGTAAKLYIDGTQVASGTVPAKLSSVKDQSLNTIGR SPWPDNLFKGAVSNFRVYDAALTADQVAAISTADASIHAGELTGSVLNGIIIPTTVDDPFISLPTANGVTWASSD SSVIATDGTVNQPAKGEAAKTVTLTAAVTIRGQTATKEFTVTVNPTTKTAAEQLKEAAAGYVIPSVVRSGDALPA AVNGTTVTVTSTKDVAVEDGKITIDGDEATTGTITVEFSKNGLAGIEPITKVFTVKVLPAAKSATIAAYDCNATS ADEANNGDIAYSMHLALQNADGSYTPYNENYGIFFARSPKAQNLNENLDGNDYRSLKDPSLLRMADGTYGVISVR TNRGTATGDSTAKSSVLIATSEDLLTYSEQENSGSIVDLGETNGVNAPYAVYDTASKQYVVGWADDNGVAKYTTF DSLKGSASKHGSVLYGSIAKSGVLDADGVQGIANFRSGATIAVDEATVKALNTRYGRSENTGTSNLTDITVEKGS SIDEMTSQLPKNVDLTYSDGSTGSLPISSWNTEGIDLTKVGDYTVTGTVKQTEYQIPFAEDRADPSVYKWQWTHE VDGKEVTETKFLMIASNDIQGDVTWQHGSPHMPFRMADTISGLADEPGNPNALIQSNGYNNKEVSLLKAGDKDSE GNAIMHSFWAPEIHEIDGRLTILFMAGYGNTWSNGKSVYMQLKQDADGHDLDPTDPDNWTVPTPIYRNDASLLNG NKQLAATASGGVGMSLDMTYFQDADGRSYYAWQQLGATYIATMDPKDPAHVTSSPVRIVTPEYAWNAAIAEGPNV TLRDGKLYLMFSGSGVGKTYTTGLAVADASGTDLTDPASWTVLNYPIQKSGPFNGEMQLGTGHGMWSEDEDGNQI YVFHAYATKNLGSVNAAGRDMFVRRVHWAADGMPVFDMSSSEELANKIVSVTVHVVDDAVAVDKSGLSKALASAK QLHGSDYTAASWKAFATMLASAEKVYADDTATQKDVDDTTVALVKAQAALVKIDGSDSGDGSGDSTKPSDGSSVD AGDKTCNNLGLSKTGAAVLSLSGVAVALAVAGIALTLQRKRRASuitably, the present B. Longum transitional strain comprises a glycosyl hydrolase family43_29 (GH43_29) gene. Suitably, the GH43_29 gene comprises SEQ ID NO: 15 or a sequence with at least 60% sequence identity to SEQ ID NO: 15. Suitably, the GH43_29 gene comprises a sequence with at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 15. SEQ ID NO: 15 ATGAGTTTCCATGTATCCGCGCAATCGGTTCGCGCGGTGGCCGGTGGACTCGTCGCCGCAGCGACATTGCTGTCA GGCCTTGCCCTTGCGCCGACCGCAATGGCCGCCGATTCAGCCACCGCTGACAACGCGCCCAGCGTTGCCGGTCAC GCGTATAACGAACTGCCGTATAACAATCCTGATGTCACCGTCACCCAAATCGACAATAGCGCACTGCCCAGCTAC ATGCGCAACCCCATCGGGCAGAACGAGGGTATTGACACCCCGAACGATCTTTCGCAGAACTACTACTCTGCAGAT GCATCCGCGCTGAGCTATGACGGCAAACTCTTCGTCTTCACCGGTCACGATGAGGCTTCGCCCGACTACGGCTCC TTCAACATGAAGGACTGGGGCGTATACGTCACCGATGAAGACGGCCTGAATCAAGGCAAATGGACACATTACAAG ACCATCGCCAAGGCAGACCTGTTCAGCTGGGCCACCGGCGATGGCGCGTACGCCGGCCAAGTCGTAGCCGACGAT AACGGCACCCCGAGCGACACTTCCGATGATTGGTTCTACTACTACGTGCCGGTGAAGGACAAGGCTTCTGAGGCG GCTGGACAGGACCCGTTCGCCATCGGCGTGGCCAAGTCGAAGAGTCCGCTCGGCCCGTGGAAGGATACCATCGGC AAGCCGCTGCTCACCACATCGCAAACCCAGATTGAAACCATCGATCCGGCATTCTTTGTGGACGAGGATGGCACC GGATATTTGCACTTTGGTACGTTCGGCACTCAGCTCGCCATCAAGATGAAGAAGGACGCCACAACCGGCCGCACC TCATACACCGAGGTGGAAACCAAGGCTGATGGCACCACGCCGAACCTCCACACCATGAAGGACGCGGACAGCAAC GCGAACGGCCCGAAGGGATTCTTCGAGGCGGCGTGGGTGTTCCGTAAGGGCGATACCTATTACAACGTGTACGAC GGCGGTAAGCCCGGTTCGGGCACGGCCACCTGCGTGGAATCGAACTATCAAGCTTGCATCCAGTACTCCACTTCC GACAGCCCGCTCGGCCCATGGAAGTACCAAGGCGTAATCGTGCCTTCTGGCTCGGCCACCACGATGCACCCCTCG GTGCTCCAGTTCGGCGACAAATGGTATGTGACCTATCACACCGGCGACAAGGAAGGCGGCACCGATTTCCGCCGT GCCGTGTGCATTGATGAAGTCGATTGGACCGCCGACGGCCAGATGGTTTCCACCGCCCATCCAACCAAGGCCGAG AAAACGCAGCCCTCCACCAACGTGGCTCCGTACGCAAAGGTGAGCGCCACGTTCACTGAAACGCCTGCTTGGAAG GGTTCGGTGAACGACGGCCGTGTGTTGCAAACCGCTGTGGTCCCGCCGAATCACTGGACCAACTACCGTTCTATC CCGCAATCGCAGTCCGGCGATTCTCTGGTCTACCAATGGGATGGCACTGTGCGCGTCAACTCGTCTAAGGTTTGG TTCGACGTGGATTCCAACGCTCTGCGCGCGCCCGCCTCGTGGAAGATTCAGTACTTGGACGCGGACGGCACATGG AAGGATGTCATCAACCCGAGTGCCTATACAACGACCACAGGCAAGGCCAACCCCAACGCCGTCACCTTCGATGCG GTGACCACTACTGCCTTAAAGCTCGACATGACCGGTCAAGCTGTGGATGGCGGCTATGCCTCCGTGGCCGTTGCT GAATGGGAAGTCGGCTCCGACTCCAGCGAATCGCCGGCAATCACTGCGCCGAAGAGCGTGACCACCGCCACCGGT ACTGCGCCTACTCTGCCGGCCACAGTGGATGTGAAGTACGGGAACCCAACCGTTGCCTCCCCAGTAATTTGGCGT CCAGTTGATGCTTCCTCGTATGCCAAGGTCGGTTCGTTTACGGCCTACGGCGTGGTCGCCGGCGTGCCCGGTGAG GCAAGCGAGCAGGGCAATGTGTCGGTAAATGTCACCGTGCAGGACGGCTACCAGCCTGCCGCTGATACCACGAAG CCGACTGTAACCGTTGCCGTTACTGCTAACGCAGGCAATAGCGAGTGGCTCACCACCGCTCCGTTCGCCACCGTG CAGGCCACGGACGACACCGCACCTATCGCCAAGCTGGAGATTTCCGCTGATCAAGGCAAGAGCTGGACCACCATC GCCGCGAATGCAAACGCGGCCATTGCCACGCTTTCCCAGCAGGGCGATGTCGAAGTGTGGGCTCGCGCCACCGAT CAGGCCGGCAACGTTTCCGACGTGGCCAAGGCCGGCGGCAAGGTGGACTCCGCCGCGCCAACCGTGACCGCCGCC GCCGATAAGGAGGAGCGCACGCTGACCTTGACCGCTGATGACGGCACCGGTTCCGGTGTCGCATCAATTGAATAC CGCATTGGCACAGACGGTCAATGGGCCACGTACAGCAAGCCGATTGCTGCACCGAGCGCGTCGCGCGCCACCGTG TACTACCGCGCCACCGATAAGGCCGGCAACGTGTCCGCTTCGGCGAAAACCGACATTCCATCCGACACTTCCGTG CCGCTGACCGGCTACATTGAGGGCGATGCCACCGCCACCGATGTGGACGGCAAGGCATCCGGCTGGGTCAAGGGT GCCGCCGCGTTGAACGACGGCAAGATCATTCCCGATATCACCATTGCCAACGAGGATGTCTGGGGCACTTGGCCC AACACCGGTGAGATGCGCCTCGACTACGAGTGGGACCGTGAAGTGACTATCGACTCTAGCCGCGTGCAATTCACC TCGGATGATGGCGGATTGGGTATTCCGGCATCGTGGGAATTGCAGTACTGGGACGCCTTGGCGAACAACGGTGCC GGCAACTTCGTGGATATTCCCGACGCCACCTACACTGTGACCGCCAATTCACCGTCTGCTGGCTGGGCCACCGGC GATGCCAAGGGGTGGTCTGATGGCACGTGGAACACTCCGGTCAAGACTACCAAGTTGCGTATGGTTATCACGTCC GGCTCGGCTTCTCCGGCTGTTGCCGAATGGCAGGTTCATGCCATTGACGACAGTACGCCTGAGCCGCCTGAGCCC ACACCGATCGACAAGACCGAGCTCAAGCAGGCGCTCGCTGACTCGCCTAAGGCTGACGATGCCTCCAAGTACACC GAGACTTCATGGGCGGAGTACGCGGCGGTATTGGATTCGGCGCAGCAGGTGTATAAGGCTGAGGATGCCACCGAA GCTGCGGTGGTGGATGCCGCAACCCAGCTGAAGCAGGCAGCGAAGAAGCTGGTGCTTGTAGCTACGGTGCAAGAT CGTGCCGCGCTGAGCGCTCAGCTCGATGCCGCTGCTGCCGTGGATCGCACAAAGTGGACTGATGAATCGCTGGCC GTGCTTGATTCGGCAGTCGCTACGGCGAATGCGCTGACGAGTGATGGTCAGGCCGCCCAGTCTGACGTACAGGCT GCGACTGAGGCAATCAGCGATGCCATCGCGGGTCTGGTTGAGAAGAGCACCACGAAGCCTGGCCAGGGTGGCGAT AAGCCCGGTTCCGGCACGGACAAGCCCAACCAAGGCAACGATTCCAACCAGAACAAGGGTGATGCAGACTCCGGC AAGCACAAGAAGATACCTGACACCGGTGCAGCCGTGCTTGGTGTTGGCATCCTCGCCGTGGTACTTGCTGTTGCG GGTGTAATCATCCTCAAGCGCCGCAAGTCCGGTACCTGCTAG Suitably, the GH43_29 gene may encode a protein shown as SEQ ID NO: 16 or a sequence with at least 80% sequence identity to SEQ ID NO: 16. Suitably, the protein may comprise asequence with at least 85%, at least 90%, at least 95%, at least 98% or at least 99% sequenceidentity to SEQ ID NO: 16. SEQ ID NO: 16 MSFHVSAQSVRAVAGGLVAAATLLSGLALAPTAMAADSATADNAPSVAGHAYNELPYNNPDVTVTQIDNSALPSY MRNPIGQNEGIDTPNDLSQNYYSADASALSYDGKLFVFTGHDEASPDYGSFNMKDWGVYVTDEDGLNQGKWTHYK TIAKADLFSWATGDGAYAGQVVADDNGTPSDTSDDWFYYYVPVKDKASEAAGQDPFAIGVAKSKSPLGPWKDTIG KPLLTTSQTQIETIDPAFFVDEDGTGYLHFGTFGTQLAIKMKKDATTGRTSYTEVETKADGTTPNLHTMKDADSN ANGPKGFFEAAWVFRKGDTYYNVYDGGKPGSGTATCVESNYQACIQYSTSDSPLGPWKYQGVIVPSGSATTMHPS VLQFGDKWYVTYHTGDKEGGTDFRRAVCIDEVDWTADGQMVSTAHPTKAEKTQPSTNVAPYAKVSATFTETPAWK GSVNDGRVLQTAVVPPNHWTNYRSIPQSQSGDSLVYQWDGTVRVNSSKVWFDVDSNALRAPASWKIQYLDADGTW KDVINPSAYTTTTGKANPNAVTFDAVTTTALKLDMTGQAVDGGYASVAVAEWEVGSDSSESPAITAPKSVTTATG TAPTLPATVDVKYGNPTVASPVIWRPVDASSYAKVGSFTAYGVVAGVPGEASEQGNVSVNVTVQDGYQPAADTTK PTVTVAVTANAGNSEWLTTAPFATVQATDDTAPIAKLEISADQGKSWTTIAANANAAIATLSQQGDVEVWARATD QAGNVSDVAKAGGKVDSAAPTVTAAADKEERTLTLTADDGTGSGVASIEYRIGTDGQWATYSKPIAAPSASRATV YYRATDKAGNVSASAKTDIPSDTSVPLTGYIEGDATATDVDGKASGWVKGAAALNDGKIIPDITIANEDVWGTWP NTGEMRLDYEWDREVTIDSSRVQFTSDDGGLGIPASWELQYWDALANNGAGNFVDIPDATYTVTANSPSAGWATG DAKGWSDGTWNTPVKTTKLRMVITSGSASPAVAEWQVHAIDDSTPEPPEPTPIDKTELKQALADSPKADDASKYT ETSWAEYAAVLDSAQQVYKAEDATEAAVVDAATQLKQAAKKLVLVATVQDRAALSAQLDAAAAVDRTKWTDESLA VLDSAVATANALTSDGQAAQSDVQAATEAISDAIAGLVEKSTTKPGQGGDKPGSGTDKPNQGNDSNQNKGDADSG KHKKIPDTGAAVLGVGILAVVLAVAGVIILKRRKSGTCSuitably, the present B. Longum transitional strain comprises a glycosyl hydrolase family 121(GH121) gene. Suitably, the GH121 gene comprises SEQ ID NO: 17 or a sequence with at least 60% sequence identity to SEQ ID NO: 17. Suitably, the GH121 gene comprises a sequence with at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 17. SEQ ID NO: 17 ATGCATCAATCAACACGAAAGCGGTGGCTTGCGTCAATCGGCGCGGTTGCAGCGGTCGCCACACTGGCCACCGGC GGTGCAGTCACCGCGCAGGCAGCCGATGCGCCCGTCATCAAGAATGCGGATGTGGCATATCCGTCGTTCAAGGGA TCTGATGATCCGATGAAGACGGCGGCGAACAACACCACATATAACCCTGCCGTCAGCTATCTGCAGGAGACATTC GATAACGACGTGAAGAACCTGGCCGGCATCGACACCGACCATGACTTCTGGATCGATAAGATTCTCACCCGTACT GGTGCACAGCCAACTGGTAAAGGCACGAACGACAAGGGTGCTTACTCGTATGAAGGCTCCGACGGCAACAACTAC CTGTTCACCCGTGGTCGCGCCGCCTACATGTACACGCACACGCCTAATCAGCTCGGTTTTGTGGGTGATACCGCC TACTGGGACCAGACCAGCAGGAGCGGCTTCACCGTTACCGTAAACGCTGATGGATCAAACCAGACCCTTAACGAA GACGCCTCCCAGCGCAAGCAGACGCCGAGCTACTTCACCTCCCTGTTCCAGACCGGTGGCAAGAGCCTCAAGATC AAGGAAGTCAAGTACATCACCTACAACAACGTGATGGTTGCGAACCTCACCGTGGAAAGCACGCAGGACCGCGAT GTCACACTGACCACGGCCTCGCCGTTCGCCGCCGAGGGTGCTGATGGTGCCACCGAACTTACTGGCCGCGTGAAC GTCAAGAACAACCTGACGACCATCTATCCGCGCTTCTCCGCCAACAACCAGGACGGTTCCAACTGGATCGTCAGC GGTGGCAAACTCACCAGCACGTTGAGCCTCAAGGCCAACGAACCGCAGACCGTCAAGATTCAGCTCGGCCTGATC GCCAACGAACTGCCTGACTCCACCAAGGAATATGAGGCCCGTTACACCGGCGACCTTAAGGATGCTGCCGCCTCC TACAAGGATTCCGTGACCACCTACAACAAGTGGTGGGTCGATAACGCTCCCTACGTGGACACTCCGGAAGACAAT ATCGATAAGACCGTGGTCTACCGCTGGTGGCTGAGCCGTTTCAACATGCTCGACGCCAACATGCCTGGCAACACC TTCCAGTACCCGACCTCCATCGAGGGTGTGCTCGGCTACAACAACCAAATCGTGCTCACCTCCGGCATGTTCATG ATGGACCCCAAGTGGTTCCGCAACCCCGAGTACTCCTACGGCACCTGGCTTTCCGCCGGCGATACCGCCAAGAAG AGCAAGGCGGGCTATTACTACTACCACGACAATCCGGGCGACCCGGCCAACTGGAACCATAGCTACACGCAGTAC ATCACGCGCGCCGGCTGGGACTCCTACAAGGTGCACGGCGGTCCGTCCACCGTGGCCGAGGAGCTGGCCGACCAG GGTGCCGAGGACGTGCAAGGTCTACTCGCTTCCAAGAGCGAGCCGGACAACAACGACAACCAGAACAACAATGAC AACAGCTTGATTGACTGGTCCTGGTGGTCGATGACCGGTAACGATGCCGACGCCGTTTCCTTCTCTGAGCCGGGT CGCTCCGGCCAGCGCATGGATCGCGCCGATGGTTCCGCCAATATGTGGGCCAACGCCAATGCGGCTGCTCAGGCC TACAAGGCCGCTGGCGATACCGCCAACGCCGAGAAGATGCAGGCCATCGCCGACAAGATCCAGAAAGAAGTCACC ACTGAACTGTGGGACAAGTCCGACAACCTGCTCAAGCACAAGTGGCTGAACGACGGTGCTTTCGCCAAGTACAAG GAGATCAATAACTACTACCCGTACTCCGAAGGCCTGATGCCTACCGGCAACGAAGATTACAACAAGGCTCTGCGC CTGTTCGAGGATTCCAACGAGTTCCCGATCTTCCCGTTCTTCACCGCCAACCAGGCGGACAAGGCGGCGCTGAAC TTCCCCGGTTCCAACAACTTCTCCATTATCAACGCACAGCCGCTGCTGCAGGTCTATTCAGCCGGCATCCGCAAT TACGATGCAGCCAAGAACGGTTACATCACCAATGAGCAGTTCAAGAAACTGCTGTACTGGGTGGCGTTCGCGCAC TATCAGGGCGGCGATAACAACTACCTTGATCAAAACGAGTTCTGGAACGAGGATAACAACAACGTCGGCGATGTA AACGGTGACGGCGTGATCAACAACCTCGACAAGAACCTTGACGCCGCACAGAACGGCGGCAAGATCACCTACCGC TCCTGGATCCACCACACCCAGCTCGGCACCACGAACTGGACGATGGTCGAGGACGTAGCCGGTATGGTGCCGCGC GAGGATAACAAGATTGAGCTGAACCCGATTGAGATCCCCGGCTGGAACTACTTCACGGTGAACAACCTGAGCTAC CACGGTCAAGATGTTTCCATCGTGTGGGATAAGGACGGCAGCCACTATGGTGGACCTGCTGGCTACAGCCTGTAC GTGGGGGGCAAGCTCGCCTTCACTTCCGACAAGCTCGCACACCTCATTTACGATCCGTCCACGGGCACCGTTGAG GATGCCGACAAGGCCGGCGTAACCATCACCAATGCCGCTGGTTCTGATATCAAGGCCGCCAACCAGGTTGCCTTC ACCGCCGACCAGCGTGTGACCGACCTGTTCGCCAAGTCCGGTGCCAACGTCGACTCCGCTTCCAAGTCCACCACG AATGTGGCCAAGGACGCGGACGTGACCGGTACCACCTACGCCGAGAAGGACACCAACTACCCGGCCAAGAACGCG GTGGACGGCAAGACCGTGATGGAATCGTTCTGGGGTACCAAGGGTTCTGAGAACAAGACCGACACGCTCAATATC AAGTTCAAGGACGGCAAGCAGAAGATCGACGACCTCCGCTTGTACTTCTACCAGAGCTCGTCCAGCCAGACCATC TCCGGCTATGCCGAGCCCGCCAACTACAAGTTGGAGTACCAGAAGGATGACGGCACATGGGCCCCGATTGCGGAT CAGGTGCGCACCCCGAACTACGCGGGCGCGAACTACAACCGTATCCAGTTCACTCCGGTGGAGACCACGACTATC CGCGTCACCTTCACGCCGCAGGCCGGCATGGCCGTCGGTGTCAAGGAGATCGAAGCCTACAACACCGGTATCAAG GCTGACGGCACTTCCGAGAACCAGGCTCCGCAGGTGGATGCTTACGTGTCTTCCAGCACCTCATCCGGTGCCAAG CTCGTCGGTACGGTGAAGGATGACGGTCTGCCCGCAGAAGGCGACGTCACCACCAAGTGGGAGCTGGTTTCCGGC CCCGAGGGCGGTACCGCGAAGTTCGTGGACGATACTGCTGCCAGCACCACCGTCACCTTCAACAAGGAAGGCGAC TACGTTCTGAAGCTCACCGCTTCCGATGGCGAGAAGGAAGGCTCCAAGGAAATCACCGTTCACGGCATCCCCTCT GACGGTACCGTGAACGTAGCCCCGCAGTCGAGCGCCTCTGCCAGCTACACCAACGGCTACCAGCCGAAGGACAAC GCCAAGAAGGTCATCGACGGTCAGGTGGTATACACCAACACGCCGAACGAGACCTGGAACAACTGGGGCGACAAC ACTGGTGTGGAGCCGTGGCTGCAACTGAAGTGGGCCGGCAAGGTGCCACTGAAGAAGGCCAAGGTCTTCTTCTGG ACCGATGGCGGTGGCGTGCCGATGGCCTCATCTTGGAAGCTCCAGTACGCTGACGCTGACGGTAACTGGCAGGAT GTGAAGCTGGCTGACGGCCAGTCCTACACGGTCAATCAGAACGAAGGCAACGAAGTGAAGTTCGCCGACACCGTC GAAACCGACAAGCTGCGCGTGGTCTTCCCGAAGGGCGCCATCGTGGGTGCTTCCGAGTTCGAGGCGTACGCCATC GAGCCGGTGAGCGTGGACGAAGTCAACCGACTGGTGCAGACCGGTTCCAAGGCCGATGATCTGAAGCTGCCCTCC ACCGTGAGCGCCGTATACACCGACGGTTCTCGCCGTGACCTCGCCGTCACGTGGGATAAGGTGACCGACGCTCAG CTGGCCGCCGATGCCGTATTCGATGTCAAGGGCATCGTCGCTGGTGCGCTGAGCGGTACGGTTGCACACATCGCA GCTCGTTCCGATACCGCATTGCAGACCGTGGGTAATGCGCAGCCGGTTGAGCAGACCGTCTACCAGAACGCCAAG TCCATCGACCTGCCCGCCACGGTTCCGGTGAAGTTCCCGAACGGATACAACGACGACCGCAAGGTCACGTGGAAG GATGCCGACATCAAGGCCATCGACCTGACCAAGGTTGGTGACTACGAGGTGGCTGGTACCGTCGACGACGGTTCG TCTTCCGCAGCTGCCAAGCTCACTGTCCACGTGGTTGCCGACCCGAACGGTTCCTCCACTCCTGAGCCTGAGCCT GAGCCGTTGGTCGGTTGGATTGAAGGCAAGGCGACCAAGACCACCATTTCGCCTGATTCCGAGGCGACCTGGTCA CCGGCCGAAGGCAAGCTCAACGACGGCGTAGTCGTCGATGATACTTGGCCGACCACGGATGATCAGAACGTCAAC GACAAGGTCTGGGGTTCTTGGGGCAAGGCAAAGGACGGCATGTACGCCCAGTACGACTTCGGTCAGTCCGTGACC GTTGACCAGAGCCGCGCCCAGTTCTGGGCCAACTTCGCTGAGACTGACGATTCGAAGGGTGGTCTGGAAGTCCCG GACGCTTGGAAGATTCAGTACCTCGCCGAGGATGGTTCTTGGAAGGATGTCGAGCCCACCGAGGATTACACCATT GTGCGTAACTCGCCGGCTTCTCGTGCGGATACCGATGCCAAAGGTTGGAGCACTGTGACCTTCAAGCCGGTCGCC ACCAAGTCGCTGCGACTCGTGCTCACTCCGCACACCGGCAGCAGCACCTTCGGGGCCGCCGTGGCCGAGTGGGGC GTGCATGGTATTGACGGCACCGAGCCTGAACCTACCCCGGTCGACAAGACCGCGCTCGAGTCGGCTCTTGACACA GCCAACGGCCTCGATGCAAGCCGCTACACCGCCGCTTCATGGGCTGAGTTCCAGCAAATCATTGACGCTGCCCAG GCTGTGTACGACGATGCCAACGCCACCGCAGAACAGGTCGCCGAGCAGGTGACCAAGCTCGAGGACGGCCAGAAG GCACTCGTTGCGCTCGCCACCGACGTGGAGAAGTCCACGTTGCAGGCGGCCATCGATGCGGCCAAAGCCGAGGCC GCTTCCGGCAAGTACACGGATAAGAGTGTCGAGGCCTTGAACAAGGCCATCGAGGCTGCGGAAGGTGTGCTCAAG GTCGGTGAGGTCGGTGAGGTCACTCAGGCCGCCGTCCAGGAAGCGTCCGCTTCGCTGAACAAGGCCGTCAAGGCC TTGGAAGAGAAGCCCGCCGCCGAAACGGTGAAGAAGGAGTCCCTCGAGGCTTCCATCGAGCAGGCCAAGAAGGCT GACAAGTCGAAGTACACCGAGGAGGCATGGCAGGCTCTGCAGAGCCAGATTGCCGCCGCTCAGAAGGTGTACGAC GACAAGGATGCCAAGCAGGCCGATGTCGATGCCGCACAGGATGCCCTTGACAAGGCATTTTGGGCCACCAAGGTT GAGCAGAAGCCCGGCTCCCAGCAGCCTGGTGTGACCGACACTGATAAGGATGATAAGGACAACAAGGGTGATCGT GTGCCTCCGACTGGTGCCGCGGTTTCCGTAGTTGCTGCGGCTGCCGTGCTGCTCACCGCCGCAGGCGTGACCATC CTGAAGCGTCGCCAGTCCGGCGACCACGGTTCGGCTCGCCACTCGGCCTGA Suitably, the GH121 gene may encode a protein shown as SEQ ID NO: 18 or a sequence with at least 80% sequence identity to SEQ ID NO: 18. Suitably, the protein may comprise a sequence with at least 85%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 18. SEQ ID NO: 18 MHQSTRKRWLASIGAVAAVATLATGGAVTAQAADAPVIKNADVAYPSFKGSDDPMKTAANNTTYNPAVSYLQETF DNDVKNLAGIDTDHDFWIDKILTRTGAQPTGKGTNDKGAYSYEGSDGNNYLFTRGRAAYMYTHTPNQLGFVGDTA YWDQTSRSGFTVTVNADGSNQTLNEDASQRKQTPSYFTSLFQTGGKSLKIKEVKYITYNNVMVANLTVESTQDRD VTLTTASPFAAEGADGATELTGRVNVKNNLTTIYPRFSANNQDGSNWIVSGGKLTSTLSLKANEPQTVKIQLGLI ANELPDSTKEYEARYTGDLKDAAASYKDSVTTYNKWWVDNAPYVDTPEDNIDKTVVYRWWLSRFNMLDANMPGNT FQYPTSIEGVLGYNNQIVLTSGMFMMDPKWFRNPEYSYGTWLSAGDTAKKSKAGYYYYHDNPGDPANWNHSYTQY ITRAGWDSYKVHGGPSTVAEELADQGAEDVQGLLASKSEPDNNDNQNNNDNSLIDWSWWSMTGNDADAVSFSEPG RSGQRMDRADGSANMWANANAAAQAYKAAGDTANAEKMQAIADKIQKEVTTELWDKSDNLLKHKWLNDGAFAKYK EINNYYPYSEGLMPTGNEDYNKALRLFEDSNEFPIFPFFTANQADKAALNFPGSNNFSIINAQPLLQVYSAGIRN YDAAKNGYITNEQFKKLLYWVAFAHYQGGDNNYLDQNEFWNEDNNNVGDVNGDGVINNLDKNLDAAQNGGKITYR SWIHHTQLGTTNWTMVEDVAGMVPREDNKIELNPIEIPGWNYFTVNNLSYHGQDVSIVWDKDGSHYGGPAGYSLY VGGKLAFTSDKLAHLIYDPSTGTVEDADKAGVTITNAAGSDIKAANQVAFTADQRVTDLFAKSGANVDSASKSTT NVAKDADVTGTTYAEKDTNYPAKNAVDGKTVMESFWGTKGSENKTDTLNIKFKDGKQKIDDLRLYFYQSSSSQTI SGYAEPANYKLEYQKDDGTWAPIADQVRTPNYAGANYNRIQFTPVETTTIRVTFTPQAGMAVGVKEIEAYNTGIK ADGTSENQAPQVDAYVSSSTSSGAKLVGTVKDDGLPAEGDVTTKWELVSGPEGGTAKFVDDTAASTTVTFNKEGD YVLKLTASDGEKEGSKEITVHGIPSDGTVNVAPQSSASASYTNGYQPKDNAKKVIDGQVVYTNTPNETWNNWGDN TGVEPWLQLKWAGKVPLKKAKVFFWTDGGGVPMASSWKLQYADADGNWQDVKLADGQSYTVNQNEGNEVKFADTV ETDKLRVVFPKGAIVGASEFEAYAIEPVSVDEVNRLVQTGSKADDLKLPSTVSAVYTDGSRRDLAVTWDKVTDAQ LAADAVFDVKGIVAGALSGTVAHIAARSDTALQTVGNAQPVEQTVYQNAKSIDLPATVPVKFPNGYNDDRKVTWK DADIKAIDLTKVGDYEVAGTVDDGSSSAAAKLTVHVVADPNGSSTPEPEPEPLVGWIEGKATKTTISPDSEATWS PAEGKLNDGVVVDDTWPTTDDQNVNDKVWGSWGKAKDGMYAQYDFGQSVTVDQSRAQFWANFAETDDSKGGLEVP DAWKIQYLAEDGSWKDVEPTEDYTIVRNSPASRADTDAKGWSTVTFKPVATKSLRLVLTPHTGSSTFGAAVAEWG VHGIDGTEPEPTPVDKTALESALDTANGLDASRYTAASWAEFQQIIDAAQAVYDDANATAEQVAEQVTKLEDGQK ALVALATDVEKSTLQAAIDAAKAEAASGKYTDKSVEALNKAIEAAEGVLKVGEVGEVTQAAVQEASASLNKAVKA LEEKPAAETVKKESLEASIEQAKKADKSKYTEEAWQALQSQIAAAQKVYDDKDAKQADVDAAQDALDKAFWATKV EQKPGSQQPGVTDTDKDDKDNKGDRVPPTGAAVSVVAAAAVLLTAAGVTILKRRQSGDHGSARHSASuitably, the B. Longum transitional strain comprises a GH43_17 gene and one or more genesselected from a GH43_22, GH43_27, GH43_29 and GH121 gene as defined herein.Suitably, the B. Longum transitional strain comprises a GH43_17, GH43_22, GH43_27,GH43_29 and GH121 gene as defined herein. Suitably, one or more of the arabinan-degrading GHs described herein comprises a signal peptide. A ‘signal peptide’ may refer to a short amino acid sequence, typically present at theN-terminus of a polypeptide, which allows the polypeptide to be secreted out of abacterial cell.Without wishing to be bound by theory, this may advantageously allow the present B. longum transitional strain to act as a primary degrader of complex structures of arabinan when present in high molecular weight, usually in the diet. Suitably, a ‘primary degrader’ may refer to a bacterium that is capable of depolymerizing specific polysaccharides to mono-, di-, and oligosaccharides that they can take up and ferment themselves to acidic end products suchas acetate or lactate. Suitably, the GH43_22, GH43_27, GH43_29, GH_121, GH43_24and / or GH30_5 enzyme may comprise a signal peptide. Suitably, each of the GH43_22, GH43_27, GH43_29, GH_121, GH43_24 and GH30_5 enzymes may comprise a signal peptide.Suitably, the present B. longum transitional strain comprises a glycosyl hydrolase family genethat encodes a CAZyme that targets arabinogalactans.Suitably, the present B. longum transitional strain comprises a glycosyl hydrolase family 43_24(GH43_24) gene. Suitably, the GH43_24 gene comprises SEQ ID NO: 19 or a sequence with at least 60% sequence identity to SEQ ID NO: 19. Suitably, the GH43_24 gene comprises a sequence with at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 19. SEQ ID NO: 19 ATGAAGATAAACAATAAGGGCAAGGGCGCTCTTATCGCGGCAATTACCGCCGCGGCAACGCTATTGTCATGCGGG CTGGCCGCTGCAAGTGCCAGTGCGGCAGGTGTGAATTACCTGCCTACCATCGGCCAAGTGCCGACATACACCAAG TTCCAGCCCACAGCCGATCCGGGCAAGAACGCTAGCGATTACTTCCAGCCATATTGGTATGCCAAGAACGCCAAT GATAATGGCGGCACACACATCCAAGCGCACGGTGGCCAAGTGGTCAAGGTTGGCGACGCCTACTACTGGTATGGC GAAGACCGTTCTAACGGTTACGACAACAGCCCCGGTGTTCATGCTTATATGTCGACAGATCTATACAACTGGACC GATCTTGGTGTGGCGCTGCGTGCGGTGACCAGCAAATCTCAGTTGACGGATAAGAGCAATGCCGATTACGCCTAC TTCGACAAGGCCTACAACCTGACCAAGTCCGACGGCAGTGTGGACGCTGCCAAGGCCGACGCAATCTTCCCGTAC CTCAACACCAACCCCGATCAGGATGGTGATGGCGCGGTTGATTCCGTACAGGGCATTTTCGAGCGTCCGAAGATC ATCTACAACAAGAAGAACAAGCAATACGTGCTGTGGTGGCATTCCGATGGAAGCACCACGCCGGGCGGTTCCAAC TATGCACGTGCACTTGCGGGCGTGGCTGTTTCCGACAATCCGGCGGGCCCGTTCACTATGGTGGGTGCCTATCGT TTGCCTAACCAGAACAATTGGAAAGAAGCCGCAGGTAACCCCAGCTGGGGTGAGAACGGTGACAGCCGCGATATG ACTGTGTTCGTGGACCCGAAGGACGACAGTGCCTATGTACTGTATTCTTCCGAAGCCAATGCCACGCTGTACATC GCCAAGCTCAACGATGATTACACCAATGTAGTCAAGACCACGAATGTGGACCAGTCCGAGGGACAAAAGCAGTAC TCTGCTGACGGGCAGTACCCATACATTCTTGCAGACGCTACTACGGATGCCCCGGTGCGTGGCGAAGATTTCCAA ATCGTCAAACAAAATGGTTCGCTGGAAGCTCCTGCCGTATTCCAATATGACGGGCGTTACAACATCATCGCATCT GGTGCAACCGGCTGGGCCCCGAACAAGCAGACCTACTACACCGCCGACTCCATGCTGGGAAGCTGGACCCGTGGC GTGGAAAAGGACGATATCAACGAGAACACGTGGTACAACAACATGCCGGAAGGCGCGGATGGTCTGTTGTCCGTG GGCGATACCCGCGGCACCACATTCGGTTCGCAGTCGGCTAGTGTGCTCGCAGTAGACCAGGAGAAAGGTCACTTC ATCTACCTTGGTGACCGTTGGGATTCCGGTAAAGCCGATTCCACCTATGTTTGGCTGCCGCTGACCATCGGTGAG AACGGCACCATCGAAATGCACAATCCTGCTCAAGAAGGCGAGCCCGACGGTTGGGATCTGAGCTATTGGGGCAAC CATGGTAGCGCCAAGGGCAAGCTGGTCAACTGGACTGTGGAAACCGGCGATGATCTCCCGAAGACCGTGAACACG GGCGGAACCGTTACTCTGCCGGACACCGTCAACGTCAAGGAAGGCGACGATACCATTGCTACCAAGGTGACATGG AATGTGGAAGGCGGTACGGCAGTCAGCAAGTCGACCAAGGCTGCTGGTAACACCTACGCATTCAATGTGCCGGGA ACCTACACCATTACGGGCACTCTTGCCGAGAGCAGTAACTTCAATCCGGGCCGTACATTCCGTAGAACCATCGAT GTTTCCTGCTCCAACCCAATTTCCGGAAGTTGGAAGGAAGCTCATTGGAAGGGCGGCAGCGCGTGCCAGGTTTCT GCGTCCGGCGGTGCTTATGACTTCACGATTACGGACAACGCCAATCGGGGCGTCTGGACGGATCGCAACGAGGGC AGTGCGGTGTACCAGCCTGATGCCCTGGACGTGAACGAAATGCTGGAAACCACGGTCAAGCCGCTCGACTTGGGC GGTAATGGCGATCCGCGCGCCGGTCTGGTGGTCCGTAACGGTCTTACTGGCGCTAACGGCGGCAAGGGATATGCC ACGTTACTTGCCAGCCCAAGCGGCGTTTACATGCAGTACGATTCCAATGCCGATGGCTACATCGATAAGGAAACA TCGCATGTTGGTACCGGCTTCGGCGACCAAGTGCAGCTCAAGCTGGAGCGCACCTCAACCGATACTCTGAAAGGC TACTGGCGTGCTTCCGCGAACGATGAATGGCAGGATGTCGCTACGGTAACGCTGACCGGTGCGGACGTAACCGGG CTCGATGCCGGTGCTTTCGCCACGTCGAACAGCAATGCCGGCGCATTCACCGTGGCCTTCAACGGCACTGCGTTC GGTTCGCAGACTGCTGCTGTGGAGTCCATCGCGGCCAAGGGCCCTGAAGCCACTATCGCCAAGAGGCAGACGCTC GCGCATAAGGACGTGACGGTTACCGCTACGCTCACCAATGGCAAGACGCGTGTACTGGAGCCAGATGAATACACG TTGGAAGGCTTCGACACCACCAAATTGGGCGAGCAAACCGTGACGGTACGCCTTGTCACTGATTCTTCAGTAACT GCCACGCTCACCGTGACTGTGGAAAGCAACCTTGCCCGGTTGTTCTGCTCGTCCGCCGCAGCCTCGAAGTATGAG CCGGCCAGCAGCTGGGCCTCCGCTTCTACGGCCGACCTGACTTGCGACAACAATCTGAGCACCAACTGGTCGAAC TGGGGCACCGGCGACACCTCGCCGTGGCTCAGCTACACCTTCGATAAGGCATATCAGCTGGGCAAGCTCAGCGTT GCGGTGGATAAGGCCAAGGGCGAGGCCGCTCCGAAGAGCTTCACTGTATCGTACCTAGCTGAAGACAACGCCACG TGGACTGATGCCACGCTGCCGGCAGTCACTGTGAATGGTGCTGCTGGAGCCGTGACGGAAGCCGATGTGAGCGCT CTGCCCGCCACCAAGGGCATTCGCCTCAACTTCACCTACGCCGATGGCAATGACTATGCCAAGATCGCTGAAGTA CGCATCGCCGAAGGTGAAGCAACGCCAAAGCCGCAGCCGTCTAGTAACGCCAATCTTGCTGATCTGACTGTGGAT GGCAAGACGGTTGACGGATTCTCCGCGGATATCACCGAATATGCCGGTGCGCTGGCCGGAGACGCTGCTTCTTAC CCGACGGTGGAGGCGACTGCTGCTGACGCGAAGGCTACGGTGCAGGTGGAGCAGGCTTCGACCGAGAACAGCGGC GTGGCCACGGTGACTGTAACTGCTGAGGATGGCACGGCGGAAACCTACACAGTGACATTCGGCGAACTGCCTCAG TTGGCCGAGCTTGCTGTGGAAGTGACCAAGGATTCCTATCAGGTAGGCGATAAGTTCAACGCTGCCGATGTGAAG GTATCCGCCATTTACAAAGTCGGCGATACCGAAACGCTGCGCAAGCTGATTGATCCAACTGATGGTGATCTGAAG TTCACTGGCTTTGATTCTGCCACCGCAGGCACGAAGACCATCACCGTCTCTTATCGTGGCGTGAACGCGACGTTC GAAGTCACGGTCACGGCCACGGAGGTCACTCCCGGCCCTGGAGAGCAGAAGCCCGGCGATACCAACAATCCTGGC AACACTGCTAAGCCCGGTAACACTGCCACGAATAAGCCGGCTGCTAATGGCGCTGCGCCCCTTTCGAATACGGGT GTTGCCGTGGCTGCCATTGCGGTCGTGGTTGTGGTGCTGACAGCTGCGGCTGGTGCCTTGCTCGTCATCCGCAAA CGCCGCGCATAA Suitably, the GH43_24 gene may encode a protein shown as SEQ ID NO: 20 or a sequence with at least 80% sequence identity to SEQ ID NO: 20. Suitably, the protein may comprise asequence with at least 85%, at least 90%, at least 95%, at least 98% or at least 99% sequenceidentity to SEQ ID NO: 20. SEQ ID NO: 20 MKINNKGKGALIAAITAAATLLSCGLAAASASAAGVNYLPTIGQVPTYTKFQPTADPGKNASDYFQPYWYAKNAN DNGGTHIQAHGGQVVKVGDAYYWYGEDRSNGYDNSPGVHAYMSTDLYNWTDLGVALRAVTSKSQLTDKSNADYAY FDKAYNLTKSDGSVDAAKADAIFPYLNTNPDQDGDGAVDSVQGIFERPKIIYNKKNKQYVLWWHSDGSTTPGGSN YARALAGVAVSDNPAGPFTMVGAYRLPNQNNWKEAAGNPSWGENGDSRDMTVFVDPKDDSAYVLYSSEANATLYI AKLNDDYTNVVKTTNVDQSEGQKQYSADGQYPYILADATTDAPVRGEDFQIVKQNGSLEAPAVFQYDGRYNIIAS GATGWAPNKQTYYTADSMLGSWTRGVEKDDINENTWYNNMPEGADGLLSVGDTRGTTFGSQSASVLAVDQEKGHF IYLGDRWDSGKADSTYVWLPLTIGENGTIEMHNPAQEGEPDGWDLSYWGNHGSAKGKLVNWTVETGDDLPKTVNT GGTVTLPDTVNVKEGDDTIATKVTWNVEGGTAVSKSTKAAGNTYAFNVPGTYTITGTLAESSNFNPGRTFRRTID VSCSNPISGSWKEAHWKGGSACQVSASGGAYDFTITDNANRGVWTDRNEGSAVYQPDALDVNEMLETTVKPLDLG GNGDPRAGLVVRNGLTGANGGKGYATLLASPSGVYMQYDSNADGYIDKETSHVGTGFGDQVQLKLERTSTDTLKG YWRASANDEWQDVATVTLTGADVTGLDAGAFATSNSNAGAFTVAFNGTAFGSQTAAVESIAAKGPEATIAKRQTL AHKDVTVTATLTNGKTRVLEPDEYTLEGFDTTKLGEQTVTVRLVTDSSVTATLTVTVESNLARLFCSSAAASKYE PASSWASASTADLTCDNNLSTNWSNWGTGDTSPWLSYTFDKAYQLGKLSVAVDKAKGEAAPKSFTVSYLAEDNAT WTDATLPAVTVNGAAGAVTEADVSALPATKGIRLNFTYADGNDYAKIAEVRIAEGEATPKPQPSSNANLADLTVD GKTVDGFSADITEYAGALAGDAASYPTVEATAADAKATVQVEQASTENSGVATVTVTAEDGTAETYTVTFGELPQ LAELAVEVTKDSYQVGDKFNAADVKVSAIYKVGDTETLRKLIDPTDGDLKFTGFDSATAGTKTITVSYRGVNATF EVTVTATEVTPGPGEQKPGDTNNPGNTAKPGNTATNKPAANGAAPLSNTGVAVAAIAVVVVVLTAAAGALLVIRK RRASuitably, the present B. longum transitional strain comprises a glycosyl hydrolase family 127(GH127) gene. Suitably, the GH127 gene comprises SEQ ID NO: 21 or a sequence with at least 60% sequence identity to SEQ ID NO: 21. Suitably, the GH127 gene comprises a sequence with at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 21. SEQ ID NO: 21 ATGAACGTTACAATCACTTCCCCGTTCTGGAAGCGGCGTCGCGACCAGATTGTCGAATCCGTCATCCCCTACCAG TGGGGCGTGATGAACGACGAAATCGACACCACAGTGCCCGACGACCCGGCCGGTAACCAGCTGGCTGACAGCAAA AGCCACGCGGTCGCCAATCTGAAGGTTGCCGCCGGCGAATTGGACGACGAATTCCACGGCATGGTGTTCCAGGAT TCCGACGTCTACAAGTGGCTTGAGGAAGCCGCTTATGCGCTGGCCTACCATCCGGATCCCGAACTCAAGGCGCTG TGCGATCGCACGGTCGATCTCATCGCCCGCGCTCAGCAGCCGGACGGCTACTTGGACACTCCGTACCAGATCAAG TCCGGCGTATGGGCCGACCGCCCGCGCTTCAGCCTGATTCAGCAAAGCCACGAGATGTATGTGATGGGTCACTAC ATCGAAGCCGCCGTCGCCTACCATCAGGTGACCGGCAACGAGCAGGCCCTTGAAGTCGCCAAGAAGATGGCCGAC TGCCTGGATGCCAACTTCGGGCCCGAAGAAGGCAAGATTCATGGCGCCGACGGCCACCCGGAAATCGAACTCGCC CTCGCCAAACTGTACGAGGAAACCGGCGAAAAGCGTTACCTGACGCTCTCCCAATACCTCATCGACGTGCGCGGC CAAGACCCTCAGTTCTACACCAAGCAGCTGAAGGCCCTGAACGGCGACAACATCTTCCCCGACCTCGGCTTCTAC AAGCCCACCTACTTCCAGGCCGCCGAACCTGTGCGCGACCAGCAGACCGCGGATGGCCACGCCGTGCGCGTCGGC TACCTGTGCACTGGTGTGGCCCATGTGGGCCGACTGCTCGGCGATCGGGGACTGATCGACACCGCCAAGCGTTTC TGGACGAACATCGTCGCCCGTCGTATGTATGTCACCGGCGCGATTGGTTCCACCCACGTGGGCGAGTCGTTCACC TACGACTATGATCTGCCGAACGACACGATGTACGGTGAGACCTGTGCTTCCGTGGCTATGAGCATGTTCGCCCAG CAGATGCTCGACCTCGAGCCCAAGGGCGAATACGCCGACGTGCTGGAGAAGGAACTGTTCAACGGTTCCATTGCC GGCATCTCGCTCGACGGCAAGCAGTACTACTACGTCAATGCACTGGAGACCACGCCTGACGGACTGGATAACCCG GACCGTCACCACGTGCTCTCCCACCGCGTCGACTGGTTCGGCTGCGCCTGCTGCCCGGCCAACATCGCCCGACTC ATCGCCTCCGTGGACCGCTACATCTACACCGAGCGCGACGGCGGCAAGACCGTGCTGAGCCACCAGTTCATCGCC AACACAGCCGAATTCGCTTCCGGCCTGACGGTCGAGCAGCGTTCGAACTTCCCGTGGGATGGCCATGTGGAATAC ACGGTGAGCCTGCCCGCCAGCGCCACTGACAGCTCGGTCCGTTTCGGACTGCGCATCCCCGGCTGGTCGCGGGGC TCCTACACGCTGACCGTGAACGGCAAGCCCGCAGTGGGTTCGCTGGAAGACGGCTTCGTATACCTTGTGGTCAAC GCCGGCGATACGTTGGAGATTGCGCTCGAGCTCGACATGTCCGTGAAGTTCGTGCGCGCCAACTCCCGCGTGCGC TCCGATGCCGGTCAGGTGGCCGTGATGCGCGGACCGCTGGTCTACTGCGCCGAACAGGTCGATAATCCCGGTGAT TTGTGGAACTATCGTCTGGCCGATGGCGTCACCGGTGCGGATGCCGCTGTGGCTTTCCAGGCCGACTTGCTGGGT GGAGTCGATACCGTTGATTTGCCGGCAGTGCGCGAGCACGCCGACGAGGATGACGCGCCGCTGTACGTGGATGCC GACGAACCGCGTGCGGGTGAGCCCGCGACGCTGCGCTTGGTGCCGTACTACTCGTGGGCCAACCGCGAGATAGGC GAGATGCGTGTCTTCCAGCGTCGATAA Suitably, the GH127 gene may encode a protein shown as SEQ ID NO: 22 or a sequence with at least 80% sequence identity to SEQ ID NO: 22. Suitably, the protein may comprise a sequence with at least 85%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 22. SEQ ID NO: 22 MNVTITSPFWKRRRDQIVESVIPYQWGVMNDEIDTTVPDDPAGNQLADSKSHAVANLKVAAGELDDEFHGMVFQD SDVYKWLEEAAYALAYHPDPELKALCDRTVDLIARAQQPDGYLDTPYQIKSGVWADRPRFSLIQQSHEMYVMGHY IEAAVAYHQVTGNEQALEVAKKMADCLDANFGPEEGKIHGADGHPEIELALAKLYEETGEKRYLTLSQYLIDVRG QDPQFYTKQLKALNGDNIFPDLGFYKPTYFQAAEPVRDQQTADGHAVRVGYLCTGVAHVGRLLGDRGLIDTAKRF WTNIVARRMYVTGAIGSTHVGESFTYDYDLPNDTMYGETCASVAMSMFAQQMLDLEPKGEYADVLEKELFNGSIA GISLDGKQYYYVNALETTPDGLDNPDRHHVLSHRVDWFGCACCPANIARLIASVDRYIYTERDGGKTVLSHQFIA NTAEFASGLTVEQRSNFPWDGHVEYTVSLPASATDSSVRFGLRIPGWSRGSYTLTVNGKPAVGSLEDGFVYLVVN AGDTLEIALELDMSVKFVRANSRVRSDAGQVAVMRGPLVYCAEQVDNPGDLWNYRLADGVTGADAAVAFQADLLG GVDTVDLPAVREHADEDDAPLYVDADEPRAGEPATLRLVPYYSWANREIGEMRVFQRRSuitably, the present B. longum transitional strain comprises a glycosyl hydrolase family 30_5(GH30_5) gene. Suitably, the GH30_5 gene comprises SEQ ID NO: 23 or a sequence with at least 60% sequence identity to SEQ ID NO: 23. Suitably, the GH30_5 gene comprises a sequence with at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 23. SEQ ID NO: 23 ATGAAGGTACTGAGCAAATCGCTTGCTGCAATGGTTGCGGCGGCAACACTAGTGGGAGGAGGGGCGTTTGCGGTT GCCGGCACTGCGTATGCGGCTGATAACGATGCCATTACCGTGACCCCGAACCCGTGGTATGCCAACAGTTTCGAT GGCTGGGGCACCTCGCTGGCTTGGTTCGCCAACGCCACCGGCAGCCTCGGCGAGGAATCGGCCATCACCACCAAT CTCGGCGATGACGCTTCCAAGGCTAAGGCTGTGGAATACGGCAAACAGCTGCGCGAACAGTTCTACCAGTCCATC TTCGGTGATGAAGGACTGGACCTGAACATGGCCCGCTACAACGTGGGCGGCGGCAATGCCTCCGATGTTGCCTAC GGCTACCCATTCATGCGCCAAGGCGCTGCCGTGCCTGGCACGTGGAAAGATGACGCCACCGGCTCCGGCACGTAT GGCAATGGCGTAACCACCAAGCAGGCCGACAAAGACAAGCTGGCTGCGGCATTCGACCCGACTGACGACAACCAG TATGACTTCTCCAAGTCCGCCGCCCAAGACTGGTGGATTGAGCGCGGTGCCACCGGCGATAACCCTGACATCACC GACGTAGAGGCCTTCGCCAACTCCGCTCCGTGGTTCCTGACCAACAGCGGTTACGCCACTGGTGGACGTAACTCC GGTAGCAATAATCTTGCAAACCCTGAGAAATTCGCTCAGTACATGGCCAAGAACGTCGAGCACCTCGAAAGCCTT GGCGCAAACGTTGACACGGTCGAGCCGTTCAACGAGTCCGAGACCAGTTACTGGGGCACTCCGGGCGACATGGCT TCGAAGTACACCGATGAGAGCGATGACAACACCAAGCTCATTAACAACTACTGGGATAAGTACTACTCCGACAAA GATAAGTCCGTCACCCCATACGCCAACGCGCTGAAGAAGCCGCAGGAGGGTATGCATGTCAGCAACGCCCAGCAG CAGCAGACGATTACCGCACTCGCTGAGGCGCTCAAGGACAATGATGACACCATCATCGCAGCCACCGATGCCACG AACTCCGCCGACTTCGTCAAGTCGTACAACCAGTACCCGCAGGCGATCAAGGACCTTATCGGCCAGTACAACGTT CACGCCTACTCCGACAGCAACCAGATGCAGTCGCGCGATATCGCTCAGGCAGACGGCAAGAAGCTGTCGATGAGC GAGGTGGACGGCTCCTGGCAGTCTGGCTCCTACAACCCGTACGGTTTCGACAACGCGCTGGGCATGATGAGCAAG ATCAGCTCCAACGTCACCCGCCTGCAGTCCAAGGACTTCACCTTCTGGCAGGTGGTCGAGGACCTCTACAACATG CAGATGGGCTCGAATGTGAATCCGGCCGGTGAGAACACCAACTGGGGCACCGTGCTCATCGACTTCGACTGCACC GTGGCTGGCATGGACGGCAAGCTCTACTCCGAGCGCCGCGTGAACAACAACGGCGGTACCACCGATGGACTTGAA CCGTGCACGGTTATTGCAAACGCCAAGTACAACGGCGTCAAGGCCATCACCCACTTCATCCACGCGGGCGACAAG GTCATCGCCAACAACGATGAAGACAACAACATGACTGCCACCTCCGACGATGGCAAGACACAGACCGTCATCCAC CGCAACTCCGGCACCTCTGACCAGACCTTCGTCATCGACCTGTCGAAGTACGGCGAGATTGCCGACAACGCTTAC GGTGAGCTCTACCTGACCACCGAAACCTCTGCCGAAGACAAGAACGCGGGTGTCGATTCCGCCACTCCGGAAGTC TTCGCCAAGACCAGCAACGTCAAGCAAGCTGAAGGCTCTGTGATGATTGACAAGGCTGCCAAGACCGCTACGGTC ACTGTGCCCGCCCGTTCTATCGCCTCCATCCAGCTCACTGGCGTGACCGGCTACGCCAAGGATGCTGCCGTCGAG ACCGGCGACACTTACCAGCTCGTTGGTAAGCAGTCCGGCAAGGCCGTGGCTGATACCACTTCTGGTGATTCCGCG CTGTCCCTGGCCAACGTCGCTTCCGATGCCGAGAACGCCAAGAAGCAGACTTGGACCTTTACCCAGATCGAGCAG CCCGCCGACTCCGAGCGCCCTGATCTCAAGGTTTATGTGATTACTAACGCCGAAGGCAAGGTGCTGGTGTCCAAG GATGGCACGAACGCGCTTTCCAACGAAACGGTTGAGGCCGCTAAGTCCGACCCGGCTGCCAAGTGGATTCTCAAC ACTTCCGATGGTTCGACCTACCAGCTGCTCAATGCCGCGACTAAGACGAACCTCGATGTGGATAACTCTGGTACC ACAGTCGGCACGAAGGTTGGCTTGTGGCAGTCACCGAGCGGCACTTCGCCGTCCGCCAACCAGACATGGACTCTA CGCAATGTAACGCCGACCAGCCAGAAGACCGTGAACGTGCAGACCGCCGTTAACGAGAAGGCCGCGCTGCCGACC GAAGTCACGCTCTACTACACCTGGGGCGAAGGCAAGGCCACGGTTGCCAACTGGGATACTTCCAAGGTCGATGTG GCCAAGGAAGGCACCTACGAAGCCACCGCTACCGCCACCGATGTGTACGGCAACGAGTTCAATGTCGCCGCTACG GTCTACGTTGGCGCGCTCACCGTTTCCGATCCGGTATCGGCTACAGTGCTGGCCGGCACCAGTGCGAGCGAGGCG AAGGCCGCGCTTGAGGCTGCGCCGGTGTATCTGCACGTCAAGGCATCGCCTGCATTCGAGGGCGATGCGGCTAAG GTTACGTGGAACTTCGATGGGCTTGATACCAAGCTCGCCGATGCCAAGGCTGGCGACAACATTGCCGTGACCGGT ACTTACCAGCTGGACGACGCGACCACGATTGCGCTGAAGGGCGCGATCTATGTCACCGCCGCCACGCCTGAGAAT GTGGCCGACACTGCTTCCAGCCTGACCGTGACCAACCAGCAGACGGAATACAGCAAGGGCGATCAGTGGAAGAAG CTCACCGATGGTGACACGTCAGCTGAAGCCTGGGTGACGTGGAACTCTGCTGGTGACTATTCCGCCAGCCCGACC GCCACGATTGACTTCGGCTCTGAGTGTGAGCTTAGCAGCGTGACCATTACGTATGGTGACAAGGCTCCGGCTTCC GCCAAGGCCGAGTACACCACTGATGGCGAGACGTGGATGCAATTCGGTAGCGATGTTAAGCCTGCCGCAGGCCAG ACGGTGACGTTCAAGGCCGATAAGGGCACAGTGAATGCCACGAAGGTGCGCATTGTGAACACCGTGAACAACGAC TACATGAACGCCACCGAAATTCAGGCATTCGTGACGCCGGTTCAGGGTGCTGCGAAGAACATCGCCGCGGCCTCT GGCACGAACTTCTCGGTGAACTTCCAGGAGGGTGCCTCCGCTTCCAAGGCCATCGATGGTGACACTACGTCAAAG GGTTGGTCCACTTGGGCTTCCACCGCCTCGACGGTGGACCCGGTCGCCACGTTCACCTTCGACGAAGCTCAGACC ATCACCGAAGTGAAGACCTTCTTCTACTACGATGGTCGTGCGTCTTGGCCGAAGAGCCAGACGCTGGAATACCAG GATGAGGCTGGCGAATGGCATGGAGTCGGTACCAAGGATGGCTGGAAGATACAGGCCGGCGATGCCGGCTCTGGC TCCGACGGCATCACCGCCGCCGACACCCCGACCGTTGACTTCGTGCTCGGCACCCCGGTAAAGGCCAAGGCCATC CGCCTGACTAACACATTGCAGGACACCAAGGTGTACATCAACGTGGCTGAGATCCAGGTGTTCGCACAAGACAGC ACGGTACTCACCCCGCAGCCAGCATCCGATGCCACGCTGGGCGACCTGCGTCTTGACGGCGAAACCGTTGAAGGC TTCGACCCGGCCAAGACCGACTACACGGTTGATCTGCCGGTCGACGCCGAGGCAAACCCGGTGCTGCAGGCCTTC GCCACCGACAATGCCGCCGCCGTCAAGGTGACTGGCGACGCGGTTGAGAACGGCCAGCTTGGCGGCAAGGCCGCC ATTACGGTGACCTCAGCCGACGAGTCTGAGACGAAGACCTACACGGTGACCTTCAACGCCTTCACTTTGGCTTCG CTCAAGGTGATCGGACCCACGAAGACCGAGTACGCCATCGGCGACAAGCTCGATACCGCCGGTCTGAAGGTGACT GCCGTCTACCAGAGTGGCGACAAGACCAAGGAAGTGCCGGTCGCTCTTGACGACCCGCAGCTTGCGATTGGCTCG TTCGACTCCACCACCGCAGGCAAGAAGGCGATTACCGTCTCCTACCGTGGTGTGACCGCGACCTTCAACGTCACG GTCAAGGCCAACGCAGTCGCCCCTGGCCCTGAAGAACAGAAGCCCGGCAACACCAACAAGCCCGGTGCCACCGGC AGCGGCAACAAGAACACGGTGGCCAACACCGGTTCCAGTGTTGCCGCCATCGCTGGCGCTGTCGCTCTGCTGGCC GCTGCCGCGGGTGCACTGTTCATGCTGCGCAAGCGTGCATAG Suitably, the GH30_5 gene may encode a protein shown as SEQ ID NO: 24 or a sequence with at least 80% sequence identity to SEQ ID NO: 24. Suitably, the protein may comprise a sequence with at least 85%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 24. SEQ ID NO: 24 MKVLSKSLAAMVAAATLVGGGAFAVAGTAYAADNDAITVTPNPWYANSFDGWGTSLAWFANATGSLGEESAITTN LGDDASKAKAVEYGKQLREQFYQSIFGDEGLDLNMARYNVGGGNASDVAYGYPFMRQGAAVPGTWKDDATGSGTY GNGVTTKQADKDKLAAAFDPTDDNQYDFSKSAAQDWWIERGATGDNPDITDVEAFANSAPWFLTNSGYATGGRNS GSNNLANPEKFAQYMAKNVEHLESLGANVDTVEPFNESETSYWGTPGDMASKYTDESDDNTKLINNYWDKYYSDK DKSVTPYANALKKPQEGMHVSNAQQQQTITALAEALKDNDDTIIAATDATNSADFVKSYNQYPQAIKDLIGQYNV HAYSDSNQMQSRDIAQADGKKLSMSEVDGSWQSGSYNPYGFDNALGMMSKISSNVTRLQSKDFTFWQVVEDLYNM QMGSNVNPAGENTNWGTVLIDFDCTVAGMDGKLYSERRVNNNGGTTDGLEPCTVIANAKYNGVKAITHFIHAGDK VIANNDEDNNMTATSDDGKTQTVIHRNSGTSDQTFVIDLSKYGEIADNAYGELYLTTETSAEDKNAGVDSATPEV FAKTSNVKQAEGSVMIDKAAKTATVTVPARSIASIQLTGVTGYAKDAAVETGDTYQLVGKQSGKAVADTTSGDSA LSLANVASDAENAKKQTWTFTQIEQPADSERPDLKVYVITNAEGKVLVSKDGTNALSNETVEAAKSDPAAKWILN TSDGSTYQLLNAATKTNLDVDNSGTTVGTKVGLWQSPSGTSPSANQTWTLRNVTPTSQKTVNVQTAVNEKAALPT EVTLYYTWGEGKATVANWDTSKVDVAKEGTYEATATATDVYGNEFNVAATVYVGALTVSDPVSATVLAGTSASEA KAALEAAPVYLHVKASPAFEGDAAKVTWNFDGLDTKLADAKAGDNIAVTGTYQLDDATTIALKGAIYVTAATPEN VADTASSLTVTNQQTEYSKGDQWKKLTDGDTSAEAWVTWNSAGDYSASPTATIDFGSECELSSVTITYGDKAPAS AKAEYTTDGETWMQFGSDVKPAAGQTVTFKADKGTVNATKVRIVNTVNNDYMNATEIQAFVTPVQGAAKNIAAAS GTNFSVNFQEGASASKAIDGDTTSKGWSTWASTASTVDPVATFTFDEAQTITEVKTFFYYDGRASWPKSQTLEYQ DEAGEWHGVGTKDGWKIQAGDAGSGSDGITAADTPTVDFVLGTPVKAKAIRLTNTLQDTKVYINVAEIQVFAQDS TVLTPQPASDATLGDLRLDGETVEGFDPAKTDYTVDLPVDAEANPVLQAFATDNAAAVKVTGDAVENGQLGGKAA ITVTSADESETKTYTVTFNAFTLASLKVIGPTKTEYAIGDKLDTAGLKVTAVYQSGDKTKEVPVALDDPQLAIGS FDSTTAGKKAITVSYRGVTATFNVTVKANAVAPGPEEQKPGNTNKPGATGSGNKNTVANTGSSVAAIAGAVALLA AAAGALFMLRKRASuitably, the present B. longum transitional strain comprises a glycosyl hydrolase family 43_32(GH42_32) gene. Suitably, the GH42_32 gene comprises SEQ ID NO: 25 or a sequence with at least 60% sequence identity to SEQ ID NO: 25. Suitably, the GH42_32 gene comprises a sequence with at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 25. SEQ ID NO: 25 ATGACCGCAACCATCAGCAACGGTGTATCCGCCAGCTACAGCCCTGCGGAAGACGAGCTCGGCGCAGCTGACCCC ACCGCCTTGCTTGCCGAATCTGGCGATTTGAAGCCGCTGGCCGAACGCACTTATACGAATCCGGTTCCATATGCG GACGGTAAGTCCCATACCGCGCCCGACCCGTTCGTGCTCAAATACCGCGACCTCTACTACTGCTATGCCACCGAC GAGCACGGCATTCTGGTCTCCACCTCACCGGACATGGTGCACTGGACCTCACATGGATTCTGCTACACCGAAGCC GGACGCAGAAACTTCTGGGCCCCATCGGTGATTCTCATCAACGGCGTCTTTCACATGTACTTCTCGAATATGCCG GCCGAGGAGACCGACACCCACACGGAAATCATGCGTGTGGCCGTGAGCGAGGATCCGCTCGGCCCGTTCGAAAAG AAAGCGGAGCTGTTCAACACCTTCGCCATCGACTCCCAAGTGGTCTATGGCGATGACGGCCAGTTGTACTTGCTT TACGCCGACAATCAGGTCACCGGCCTGAGCGATGACCGGCCCGGAACCTCCGTGATGATCGATCGCCTTGTGACC CCGTATTCGCGTGAGAACAAACCGCGCCCGCTCATCGTGCCCACCATGGACGAGGAGATCTTTGCCCGCAACCGT TTCGGCGATGGCCGCGACTGGCACACCGTAGAAGGCGCCACATACTTCGCCTACCGTGACCGCGCGTTCATCACC TACTCGGCCAACGCCTACGAGCATGAGGACTACTTCGTCGGATACTCGTACGCACAGCTGCCGAATAAGCAGGCC GACGCCCACATCGATCAGCTCGATTGGACGAAACAGCTCAACGAGAACCGCTTCGATCCGCTGCTTATCCGCAGC CCAAAGGTTGAAGGCACGGGCCACAACTCCATAGTCAAAGCGCCCAATGCCGTTGATGACTGGATTGTCTACCAC GGCCGTAACGCCGATGACGAGCTGTATGTGGGCACCGAACAGCGCGTAATGCGCATCGACCCGCTGTACTACGCC GAAGGAGGGCTCGACACCCCAGGACCTACCGCCGCCGCTCAAAGCGCACCGCTGTATGGCACTGTGCATGATGAT TTTGCGGATGGCCTGAACGCCGGATGGTCGGTTATTTCCGGTGCGGCCCACACCGAATCCGATGTGGACGGTCAC GCGCTTGTTGCCGACGAATCCAGTGTATTCATCGCTGTGTCGGGCAAATCGTCCGCAACCCAAGTGATTGACGTC TGGGCCAAAGCTCCCGTCACCCCACTGGGCGCACGATTCGGTATCGTGGTGCGGTACCAGGATGCCAACAACCTC ACCAAACTCGAGGTGGATGCTGGCCGTCAGGTAATTAGCGTGGTCGATGTGATCGGCGGCGTTGCCTCCGAACGC GTGACCAATGCCGACCTCCATGACTTCGATTCCCATGCCTGGCATGAGTACCGGCTTGAGCGCCGCTACTGCAGG CTGGAGATCCGCATTGATGGCCGTTTCGCCGCGTCCTGCACCATCAGTGATAAGCCCGGTCGGGCGGGATTGTTC TCGTTGCGAACGGGGGCCGCGTTCAGCGCATATGCGGCCACTGAACATGTGAATCTGTGGGGTGCCGGATTGCGG GATCTCGGTCGAGAATTGCATGCTGACCGCCGACTCGTCATCGACGGCGGCGTGAGGTCCAGCGGCGTGTGTCCG GTAACACTCGAACTGGCATACCCGCTGGTCAGCAACCGTTTCGTCCTTGATTTCGCTGGGCAGACGAGCCGTGGG CAGGCGCTGTTGTCTCTTGGCGAATACCGTTTGTCCGGCACGGCATCATCCGTGGAGTTCATGCGCAACGGCAAG TCTCTGCCTTCCACCCCGGAGCCGGCCAGGCTGCGTGTCTTTGAAGACAACGTCCGCCGTGACCGTTCGGGCCGA GCCGTGCTCACCATCCGTATCGAAGCTCTGAACGGCACGATGCGACTGCACCTACGTGGCAAAACCTGGCAGGTG CCGTTTGCGGACAATGCGGCCCGTGCCCGTATCACTCTTGATCGCGCATCCCTGACCGGATACGAGAGGACATCG CTGGAATCCAGCATCGAGGAAAGGAGTGCGTCCGGCAATTGA Suitably, the GH42_32 gene may encode a protein shown as SEQ ID NO: 26 or a sequence with at least 80% sequence identity to SEQ ID NO: 26. Suitably, the protein may comprise asequence with at least 85%, at least 90%, at least 95%, at least 98% or at least 99% sequenceidentity to SEQ ID NO: 26. SEQ ID NO: 26 MTATISNGVSASYSPAEDELGAADPTALLAESGDLKPLAERTYTNPVPYADGKSHTAPDPFVLKYRDLYYCYATD EHGILVSTSPDMVHWTSHGFCYTEAGRRNFWAPSVILINGVFHMYFSNMPAEETDTHTEIMRVAVSEDPLGPFEK KAELFNTFAIDSQVVYGDDGQLYLLYADNQVTGLSDDRPGTSVMIDRLVTPYSRENKPRPLIVPTMDEEIFARNR FGDGRDWHTVEGATYFAYRDRAFITYSANAYEHEDYFVGYSYAQLPNKQADAHIDQLDWTKQLNENRFDPLLIRS PKVEGTGHNSIVKAPNAVDDWIVYHGRNADDELYVGTEQRVMRIDPLYYAEGGLDTPGPTAAAQSAPLYGTVHDD FADGLNAGWSVISGAAHTESDVDGHALVADESSVFIAVSGKSSATQVIDVWAKAPVTPLGARFGIVVRYQDANNL TKLEVDAGRQVISVVDVIGGVASERVTNADLHDFDSHAWHEYRLERRYCRLEIRIDGRFAASCTISDKPGRAGLF SLRTGAAFSAYAATEHVNLWGAGLRDLGRELHADRRLVIDGGVRSSGVCPVTLELAYPLVSNRFVLDFAGQTSRG QALLSLGEYRLSGTASSVEFMRNGKSLPSTPEPARLRVFEDNVRRDRSGRAVLTIRIEALNGTMRLHLRGKTWQV PFADNAARARITLDRASLTGYERTSLESSIEERSASGNSuitably, the B. longum transitional strain comprises one or more genes selected from aGH43_24, GH127, GH30_5, and GH 43_32 gene as defined herein.Suitably, the B. longum transitional strain comprises a GH43_17 gene and one or moreselected from a GH43_24, GH127, GH30_5, and GH 43_32 gene as defined herein.Suitably, the B. longum transitional strain comprises a GH43_17, GH43_24, GH127, GH30_5,and GH 43_32 gene as defined herein.Suitably, the B. longum transitional strain comprises a GH43_17, GH43_22, GH43_27,GH43_29, GH121, GH43_24, GH127, GH30_5, and GH 43_32 gene as defined herein.Suitably, the B. longum transitional strain comprises a GH43_17, GH43_22, GH43_27,GH43_29, GH121, GH43_24, GH127, GH30_5, GH 43_32, as defined herein.GH43_17 gene clusterSuitably, the B. longum transitional strain may comprise one or more genes encoding for afamily 31 glucosidase (GH31), an ABC transporter, a Lac-I type regulator, a MFS transporter and / or an AraC family transcriptional regulator.Suitably, the present B. longum transitional strain comprises a glycosyl hydrolase family 31(GH31) gene. Suitably, the GH31 gene comprises SEQ ID NO: 27 or a sequence with at least 60% sequence identity to SEQ ID NO: 27. Suitably, the GH31 gene comprises a sequencewith at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98% or atleast 99% sequence identity to SEQ ID NO: 27. SEQ ID NO: 27 ATGACAACTTCATTCACCATCGACGGCAACGCCCTGATCTGGACCGGGGACGGCGAAACCCTGCGCATCGAACCT TGGGAAGAGAACAGCGTACGTGTACGCGCCACCCGCAACCGTGGCTTCGGCCCGGTCGATTGGGCGCTTCTGGAA CCGAAGAATGAATCCGGCCGTGTCGCAGACATCGCCGTCGGCGAGGACGGCGAACACGCCAGCCTGACCAACGGC AGCATCACCGTTAAAGCGGATTCGAATCATGCTCCATTGCTGTCTGCCGGATATGAAACCTTCCGGTGTGACCTG AGCTTCTGGAACGCCGAAGGCGAACTCCTGTTCCGCGAATATCCACAAGGTGGGTCGCTTTTGCTCAAGGCGCGT GACTACACTCCGGTGTCCGGTGAAAGCTTCGCCGTGACCACGTCTTTCAGCGCCGATCCCAAAGAACGGCTGTAT GGCATGGGCGAATACCAACAGGACGTGCTTGACCTCAAAGGCTCCACCTTTGAACTTGCGCACCGTAATTCCCAA GCCTCCGTGCCGTTCGTCGTCTCCTCCAAGGGGTACGGCTTCCTGTGGCACAATCCGGCTATTGGCCGCGCCACT TTTGGACGCAACCGAACCGAATGGGCGGCTCAGTCCACTGACCAGATTGACTACTGGGTCACCGCCGGTGACTCC TACGCGCAGATCGAATCGCAATATGCCGACGCCACCGGACATGCGCCAGTCATGCCTGAATGGGGTATGGGCTTC TGGCAGTGCAAGCTGCGTTACTGGAACCAGGAACAATTGCTTGACGTGGCCCGAGGCTTCAAATCCCGGAACATC CCGCTAGACCTCATCGTCATTGACTTCTTTCACTGGCCTCATTTGGGCGACTATAAGTTCGAGGACGAATTCTGG CCTGATCCCGAGGCCATGGTCGCCGAGCTCAACAGCATGGGCGTCAAGCTCATGGTGTCTGTGTGGCCGCAGGTC TCGGTCTCATCCGAGAACTTCGTGGAGATGAAGCGCAACAACTATCTGGTAAGCGCTGAAGCTGGGCTCAATCTT GACATGATGTTCGAAGAGCCGTGCGTCAACTATGATCCCACCAACCCGGGAGCTCGCAAATTTGTGTGGGACAAG TGCAAGGCCAACTATTGGGACAAGGGCGTGCGCGCCTTCTGGCTGGATGAGGCCGAACCCGAATATGGTGTCTAC GATTTTCGCAACTACCGCTACCACATGGGCAGCGACCTCAACGTGGGTAACGTCTATCCGCAGGCTTACAACCGC GGATTCTACGAGGGGCAGATAGAAGCCGGCATGGAAGGCGAGATCGTTAACCTGACTCGATGTGCGTGGGCTGGA TCTCAACGTTACGGATCGTTGGTCTGGTCTGGAGACGTTGGCTCCACATTCGCCGATCTGAAATCGCAGATTACC TGTGCTATTCACATGGGTATGGCTGGCATCCCTTGGTTCACTACAGACATGGGCGGCTTCCATGATGGGGTGATC GATTCGGATTCATTCAAGGAGCTGCTGGCCCGCTGGTGCGCGTTCTCCTGCTTCCTGCCCGTCATGCGCAACCAT GGTGACCGCAGCCTGGGGGAGTCGACCGGCAAGCAAACCATCACCAAGGCAACCGGTGAGCACCGTTCGCCTTCG GGCGCGGACAACGAGCCATGGAGCTATGGCCCTGAAATGGAGTCCATATTCCGTAAATACATCGCCGTGCGCGAG GTCATGCGCCCGTATACCCGTGAACTGTTCCAGTCTGCCCATGAGCAGGGTCAGCCGTTGGTGCGAGGACTGTTC TACGAGTTTCCGACCGATGAACACGTGGCCGACATTGCGGACGAATACCTGTACGGTCCTGACATTCTTGTGGCT CCCGTAGTCGAGGCCGGTGCTGCTTCCCGTAGCGTCTACCTTCCTGGCGATGAGACGACCACTTGGACTGATTTG CGAGACGGTGCCGTATACGCGGGTGGGCAGAGCATCGAGTCGTCTGCAGCAATCGACACGGTCCCTGCCTTTGCG CGAGATGGTCGGGACCATGGTTTGATTGGTCTGTTGTAG Suitably, the GH31 gene may encode a protein shown as SEQ ID NO: 28 or a sequence with at least 80% sequence identity to SEQ ID NO: 28. Suitably, the protein may comprise a sequence with at least 85%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 28. SEQ ID NO: 28 MTTSFTIDGNALIWTGDGETLRIEPWEENSVRVRATRNRGFGPVDWALLEPKNESGRVADIAVGEDGEHASLTNG SITVKADSNHAPLLSAGYETFRCDLSFWNAEGELLFREYPQGGSLLLKARDYTPVSGESFAVTTSFSADPKERLY GMGEYQQDVLDLKGSTFELAHRNSQASVPFVVSSKGYGFLWHNPAIGRATFGRNRTEWAAQSTDQIDYWVTAGDS YAQIESQYADATGHAPVMPEWGMGFWQCKLRYWNQEQLLDVARGFKSRNIPLDLIVIDFFHWPHLGDYKFEDEFW PDPEAMVAELNSMGVKLMVSVWPQVSVSSENFVEMKRNNYLVSAEAGLNLDMMFEEPCVNYDPTNPGARKFVWDK CKANYWDKGVRAFWLDEAEPEYGVYDFRNYRYHMGSDLNVGNVYPQAYNRGFYEGQIEAGMEGEIVNLTRCAWAG SQRYGSLVWSGDVGSTFADLKSQITCAIHMGMAGIPWFTTDMGGFHDGVIDSDSFKELLARWCAFSCFLPVMRNH GDRSLGESTGKQTITKATGEHRSPSGADNEPWSYGPEMESIFRKYIAVREVMRPYTRELFQSAHEQGQPLVRGLF YEFPTDEHVADIADEYLYGPDILVAPVVEAGAASRSVYLPGDETTTWTDLRDGAVYAGGQSIESSAAIDTVPAFA RDGRDHGLIGLLSuitably, the present B. longum transitional strain comprises one or more ABC transportergenes. Suitably, the ABC transporter genes comprise SEQ ID NO: 29-31 or sequences with at least 60% sequence identity to SEQ ID NO: 29-31. Suitably, the ABC transporter gene comprises a sequence with at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 29-31. Suitably, thepresent B. longum transitional strain comprises a gene with at least 60% sequence identity to SEQ ID NO: 29, a gene with at least 60% sequence identity to SEQ ID NO: 30 and a gene with at least 60% sequence identity to SEQ ID NO: 31. SEQ ID NO: 29 ATGACGCATCGTAGCACCTGGTGGAAAACCGCTCTCGGCATCATATTGACGCTCATCATGATGTTTCCTGTCTAC TGGATGATCAACATCTCGTTCACTGGTAAGGCATCCATTCGTTCCGGCGACCTGTGGCCCAAGGATTTCACCTTT GACAACTACGCCCGCGTAATCGCCGACCAAATGCCCTATCTGGGCACTTCCATCCTCGTAGCGGTATGCTGCGTG ATTCTAACGCTGGTCATCGCACTGCCTGCCGCCTACGCACTGGCTTTGCTGCGCTGTCCAGGCAGCGGCGCGCTC AGCTTCCTGCTCATCGTGGCTCAGATGATTCCCGCCGTCGTGATGTCGCTCGGCTTCTACGAGATTTATAACAAC ATTGGTCTGCTCGATACGTTGCCCGGCCTGATCCTCGCCGACTCGACCATTGCGGTGCCGTTCGCGGTCATGCTC CTGACTTCTTTCATGGCCGGCATCCCGCGGTCCCTGCTTGAGGCCGCCGAAGTGGATGGAGCCTCACGTACCCGT CGCTTCTTTTCCATTGTCATCCCGTTATCGCGCAATTCGATCGTGACCGTCTCCCTGTTCGCTTTCCTATGGTCT TGGAGCGACTTCCTGTTCGCTTCCACCCTTGACTCCGGCGGCGGCAAGATGCGCCCGATCACTATGGGTCTGTAC AACTATATCGGTGCGCAGACCCAGGAATGGGGGCCGATGATGGCCACCGCAGTGCTTGCATCCATTCCCGCGACC ATCCTGCTTGTCTTCGCCCAGAAGTACGTCGCCGCAGGCGTGACCGCCGGTGCTGTTAAGGACTAA SEQ ID NO: 30 ATGACAGCCTCAACAACAAGCCCCGTTCGCCGGGCAAAGTCCGGCACTCCGGTCCGGGCCAAACTGGCCATCGCC GGATTCATTGCCCCACTGATTATCTACTTGGTAATCTTTTACGCGTTCCCGCTCATCCAGAACGTGTCAATGAGC CTGCACCGATACACGCGACGAACCTTCGTTACCGGAGATGCGCTGTTCGTGGGTCTCGACATCTACAAGGAAGTC ATTTCCTCCGTGGAGTTCTGGCCGGTTGTGGGGCAGACCTTCGTGTTCGTGGTCGTCTCGCTGATATTCCAATAT GTAATCGGCTTGGCCCTGGCGGTGTTCTTCAACGATAACTTCAAGCTCTCTGGTGTGCTGCGCGGCATCATGCTG GTTCCGTGGCTGTTGCCGCTGATTGTTTCTGGAACCGTCTGGCAGTGGATGATGGACCCTGACTCCGGCATCCTC AACATGTTCCTCGGTCTGTTTGACATCGAACCCATCTGGTGGCTCCAGGCGGATAACTCGCTGTGGGCCGTCATC ATCGCCAACATCTGGCTGGGAATCCCCTTCAACCTCGTGATCCTGTATTCCGGCCTACAGAACATCAGCGGCGAC CTGTATGAAGCCGCCTCCCTCGATGGCTGCAACGCCTGGCAGCGCTTCTGGAAGATCACCTTCCCTCTCCTGAAG CCCGTCACTTCGATCACCCTGTTGCTCGGCTTCGTCTATACATTGAAGGTCGTTGACGTGATCTGGATGATGTCC CAGGGAACCGGCACCTCGCGTACCCTCGCCACCTGGGCCTATTCGATGGCATTTGGCAAGGGAACTTCAATGACT ATCAAATACTCGGAGGCTTCGGTGCTCGGCACGATTCTCATCATCGTGGCGTTGATTTTCGGACTGATTTACCTG CGGGTCCAGAAGACCCAGGAAACCTGCTAA SEQ ID NO: 31 ATGAAGTCCAATACCGCTCTTAAGATAACCGCCGCATTATGCTCCTGCGCCATGCTTGTCGGCGTCAGCGCCTGT GGTTCGAGCAACAGCACCACGGATGATAAGGTGATCGAATGGTGGGATGACTGGACCCGCCACGAGGATGGCTCC GAGTTCGACAAACTGGTCAAGGCGTGTGCGCCCGAAGGCTACACAATTGAGCGCCAAGCCATCGCCACTTCCGAC CTGCTCAACAACCTCACCACCGCAATCAAGGAAGACAATGGCCCGGATGTTGCGGTCATCGACAACCCGATGATT CCGTCCGCCGTCGATGCGGGTTTGGTTGCTGGTTCCGACGAAACTGGTCTTGACGTTTCTGCCTGGGATGAGAAC CTTGAGGCTCCGGGCGTAGTGGACGGCCAGGCATATGGCGTGCCGCTGGGCGGATCCAACACGTTGGGTCTTATG TACAACCCCACCATCATTGAGGCAGCCGGTGTGGATGTATCCACCATCACCGATTGGGATTCGCTCAACGCGGCC ATCAAGAAGGTCGTTGACGCCGGATACAAGGGCATTACGTTCTCGGGCATCTCGGGTGAGGAAGGCGTCTTCCAG TTCCTGCCTTGGTTCTGGGGCGCAGGTGGTGATCTGTCCAAGCTTGACTCCCAGGCGCAGAAGGACGCCGAAGAC CTGCTTTCCGGGTGGATCAGCAAGGGATGGGCTCCCAAGTCCGCCACGACCAACACCCAGTCGGCCTCCTGGGAT CTGTTCCTGGCTGGCGACTACGGATTTGCTGAAATCGGCACCTGGATGCAGTCCGAGGCAGACGAGGCCGGAGCC AAACTTATTCCGATCCCCGCAAAGGATGGCGGCGTGGCCACCGTGCCGACCGGTGGCGAGTTCGCCATGGTCGCC TACCACAAGAAGGATGCGGAATCCCACTACAAGCTCGCCAATCAGGTTATCGAATGTCTTTCCGAGGACGAGACT CTGCTTAAGGTAAGCAACGCTCTGAGCAACCTCGCTGCCAAGAAGGCCGTGCGTGCCGAGCAGCTCGCGGCTAGC GACGGCTTGGCTCAGTGGAAGGAATCCATCGAGAACGCCGCCGGCCGTACCTCCGACTTGGGTCTCAAATACGAG GAAGCCTCCGCAAGCATCTCCGAATCCCTGCTGGCGGCCCTTAACGCGGCTTGA Suitably, the ABC transporter genes may encode a proteins shown as SEQ ID NO: 32-34 or polypeptide with at least 80% sequence identity to SEQ ID NO: 32-34. Suitably, the gene may encode a polypeptide with at least 80%, at least 85%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 32. Suitably, the gene may encode a polypeptide with at least 80%, at least 85%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 33. Suitably, the gene may encode a polypeptide with at least 80%, at least 85%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 34. SEQ ID NO: 32 MTHRSTWWKTALGIILTLIMMFPVYWMINISFTGKASIRSGDLWPKDFTFDNYARVIADQMPYLGTSILVAVCCV ILTLVIALPAAYALALLRCPGSGALSFLLIVAQMIPAVVMSLGFYEIYNNIGLLDTLPGLILADSTIAVPFAVML LTSFMAGIPRSLLEAAEVDGASRTRRFFSIVIPLSRNSIVTVSLFAFLWSWSDFLFASTLDSGGGKMRPITMGLY NYIGAQTQEWGPMMATAVLASIPATILLVFAQKYVAAGVTAGAVKD SEQ ID NO: 33 MTASTTSPVRRAKSGTPVRAKLAIAGFIAPLIIYLVIFYAFPLIQNVSMSLHRYTRRTFVTGDALFVGLDIYKEV ISSVEFWPVVGQTFVFVVVSLIFQYVIGLALAVFFNDNFKLSGVLRGIMLVPWLLPLIVSGTVWQWMMDPDSGIL NMFLGLFDIEPIWWLQADNSLWAVIIANIWLGIPFNLVILYSGLQNISGDLYEAASLDGCNAWQRFWKITFPLLK PVTSITLLLGFVYTLKVVDVIWMMSQGTGTSRTLATWAYSMAFGKGTSMTIKYSEASVLGTILIIVALIFGLIYL RVQKTQETC SEQ ID NO: 34 MKSNTALKITAALCSCAMLVGVSACGSSNSTTDDKVIEWWDDWTRHEDGSEFDKLVKACAPEGYTIERQAIATSD LLNNLTTAIKEDNGPDVAVIDNPMIPSAVDAGLVAGSDETGLDVSAWDENLEAPGVVDGQAYGVPLGGSNTLGLM YNPTIIEAAGVDVSTITDWDSLNAAIKKVVDAGYKGITFSGISGEEGVFQFLPWFWGAGGDLSKLDSQAQKDAED LLSGWISKGWAPKSATTNTQSASWDLFLAGDYGFAEIGTWMQSEADEAGAKLIPIPAKDGGVATVPTGGEFAMVA YHKKDAESHYKLANQVIECLSEDETLLKVSNALSNLAAKKAVRAEQLAASDGLAQWKESIENAAGRTSDLGLKYE EASASISESLLAALNAASuitably, the present B. longum transitional strain comprises a Lac-I type regulator gene.Suitably, the Lac-I type regulator gene comprises SEQ ID NO: 35 or a sequence with at least 60% sequence identity to SEQ ID NO: 35. Suitably, the Lac-I type regulator gene comprises a sequence with at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 35. SEQ ID NO: 35 ATGGTGACCATCAACGACGTGGCGCGGGAGGCAGGAGTCTCCAAAACCACGGTCTCATTCGTGCTTTCGGGCTCG CGCCCCGTTGCTGCAGCCACCGAACAACGTATCCGTGAGGCAATGGACAGACTCGGCTATACCGTCAATCATGCC GCCCGCAGCTTGTCCACTTCGAAGACCATGACCATAGCCGTGGTGACCAGCAACCGGCAGGACGCCTACTTTGAC ATTGCCCGTGGCACATACATCAACGGCTTATCCCGAGCAGCCGCCGAAACCGGCTACGACATGCTCATCACTAAC GATCCAGACGGCTCCGCTACGGAGAACGCCTGCCAATCACACAAGGCGGATGGGCTGGTTTTTTTAGACGTCAGG CAGAACGATCCGCGTGTGCCGATTGCCGCTGAATCCGGCATTCCAACAGTCTCGCTAGGAGTCCCAGTCAATCCA ATGAATCTTGATGTGGTCGACACCGACTTCACGGACATGGCGGCCTCGACCATGCGTACACTGCACGATGCCGGA CACCGCCGCGTCAGCGTCATCACGCTCAGTAGCCGGGTGATTGCCGAACAACTCAACGACACCGCTCGATTCCTC AGGGAAATCGAACGTTCCGGAGAACGACTTGGCATGCATGCCACTATCCGACATTGCTCTACAAGGCCCGGAATC ATCGACACAGACATCGCTCGCATTCTTGACGGTCGAGGTGAGGACACCGCATTCGTCATCCATAATGAATCGGCC GTATTGGTGTTCAGACGGGCAGTGGAACATCGCGGACTGCGCATCCCCGAGGATATCTCCGTCATCGCCATCAAT GAAAAGCAGATGTCGGACGCTCTGTATCTGCCATATTCCGCCTACGAAAACGACGTGGAACTGGTCACCCAATCT GCCGTCAATACGCTTGTGGACCGTATCGAACATCCCGAGCTGACGCCGACACGAACGTTGATCAAGGCCTCGTAC ATAGATCGAGACTCCGTGGCCAATATCTGA Suitably, the Lac-I type regulator gene may encode a protein shown as SEQ ID NO: 36 or a sequence with at least 80% sequence identity to SEQ ID NO: 36. Suitably, the protein may comprise a sequence with at least 85%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 36. SEQ ID NO: 36 MVTINDVAREAGVSKTTVSFVLSGSRPVAAATEQRIREAMDRLGYTVNHAARSLSTSKTMTIAVVTSN RQDAYFDIARGTYINGLSRAAAETGYDMLITNDPDGSATENACQSHKADGLVFLDVRQNDPRVPIAAE SGIPTVSLGVPVNPMNLDVVDTDFTDMAASTMRTLHDAGHRRVSVITLSSRVIAEQLNDTARFLREIE RSGERLGMHATIRHCSTRPGIIDTDIARILDGRGEDTAFVIHNESAVLVFRRAVEHRGLRIPEDISVI AINEKQMSDALYLPYSAYENDVELVTQSAVNTLVDRIEHPELTPTRTLIKASYIDRDSVANISuitably, the present B. longum transitional strain comprises a facilitator superfamily (MFS)gene. Suitably, the MFS gene comprises SEQ ID NO: 37 or a sequence with at least 60%sequence identity to SEQ ID NO: 37. Suitably, the MFS gene comprises a sequence with atleast 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 37. SEQ ID NO: 37 ATCGCCGAGTTCCATTACGCTATCGGGCATTTTCATTGTGCCGGTCATCGGATTGGTTGCTCAGGCATTCCCGGA CAGCTCGCTCTCCAGCGTGCAGATGATTGTTTCGGCATCACTCTGACCGCACTGGTTGGCGCTTGGCTGACCGGC AAACTCGCCAGCATTCTATCCCGGAAGACCGTGGCACTGATTGGTGCAGGCGGCATGCTGCTGTTCGGTCTGCTG CCGTACTTCGTGCATTCCAGTCTGGCTGCAGTCATCGCGTTTTCCGCGTTGATGGGCGTATGCCTAGGCTTTATC AACAACGTGCTGCCTACTTTGATCTCCGTGCACTACGAGGGCGATGAGCGACAGTCGATTATGGGTCAGCAGGTT GCCGTGGCCAGCATCGGTGCGATGGTGTTCATGACCGTGGCCGGCAAACTCGCCACCGCACAGTGGTATCACGCC TACCTCATCTACTTGTTCGCCGCCGTGGTGCTGGTGGTCTGCGCATTCACGCTGCCCACCAAGAATGGTGAGACG GACGAAGCCGGCCGGATTCAGGGAACGGGGCCTTCCGCGTCGATTCGCGAGGTTATGACCGGCAAACTGTGGTTC TTGGTTGTTGCCGGCTTCTTCTTCCTTCTGGCGAACAATGCCTACAGCAACAACTTGTCCCTGTTGGTCGAGCAG CGCGGCTTGGGCGATGCCGGAACCGCTGGACTGATTTCCACCATCGGACAGTTCGGCGGACTGCTGGCTGGTTTG TGCGTCGGTCTTATGGTCCGATTCGTGAAGAACCATTTGCTGATGGTCGGCTTCATTGTCGAGGGCCTGTCTTTG CTGCTGCTTGGCTGCTCGGCCAGCCTGCCACTGCTCATCATCGGCAGTTTCTTTGCCGGAGCCGGCCTGAGCATC TACTATGCGCAGGCGCCATTCCTCGTCACCGTCATCGAAAAGCCCTACCTCATCCCGCTGGGCATTGCTGCCATG ACCACGGCCAACGCACTGGGCGGATTTGCCAGCCCTGTGCTCGTCAACGCGATTAACGGACTGTTTGGTTCGCAC GCGGCCGGCGCGATGTTCATCGGTGCCGCGATTGCTCTGGCCGGAGCGGTGGCTCTCGGTGTGAGCGGATTCCAA AAGAAGTGCCTCGAAAGCGCGAAGTGA Suitably, the MFS gene may encode a protein shown as SEQ ID NO: 38 or a sequence with at least 80% sequence identity to SEQ ID NO: 38. Suitably, the protein may comprise a sequence with at least 85%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 38. SEQ ID NO: 38 MAEFHYAIGHFHCAGHRIGCSGIPGQLALQRADDCFGITLTALVGAWLTGKLASILSRKTVALIGAGGMLLFGLL PYFVHSSLAAVIAFSALMGVCLGFINNVLPTLISVHYEGDERQSIMGQQVAVASIGAMVFMTVAGKLATAQWYHA YLIYLFAAVVLVVCAFTLPTKNGETDEAGRIQGTGPSASIREVMTGKLWFLVVAGFFFLLANNAYSNNLSLLVEQ RGLGDAGTAGLISTIGQFGGLLAGLCVGLMVRFVKNHLLMVGFIVEGLSLLLLGCSASLPLLIIGSFFAGAGLSI YYAQAPFLVTVIEKPYLIPLGIAAMTTANALGGFASPVLVNAINGLFGSHAAGAMFIGAAIALAGAVALGVSGFQ KKCLESAKSuitably, the present B. longum transitional strain comprises an AraC family transcriptionalregulator gene. Suitably, the AraC gene comprises SEQ ID NO: 39 or a sequence with at least 60% sequence identity to SEQ ID NO: 39. Suitably, the AraC gene comprises a sequence with at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 39. SEQ ID NO: 39 ATGGAGCGCGATGCTTTCCGGCTGCCGGGCCTCACCGCCGGCGATGACAACCAGTATGCCGATCACACGCTCACC GGCATGGCAGCCGATGCGGCGAACGTCATAGCCGCAGGCGGTCCCGCCCCGCTGACTAGCTTCGGCACTGTCGCT CAAGCCGCCCATCTCAATCCAGATGACGGCTTCGGCATCATTGGCCATGATCTTGCACACCCATCGCACCTACAC CGGCATGACTATATGGAAATCACGCACGCCATCGCCGGTACGGTACTGGTCTGGGTCGAAGGAGAGACCAACGTG CTGACACAGGGCGGCACCATACTCATCAAGCCTGGAGCCCGTCATCTCATCTCCCCCATCATCGAATACGGGCAA ACACCACACGAGGCGGACATCCTGATTAAACCCGAGCTCATCAGGCAATGCCGCATTCCGATTCTGGAAGCAGCC GGCGCCGACCGGATGTTCATTAGCTGGCTTGACGATGACCGGCAGACCCACTGCCTGCTGGCAGCCGGCAAGCAC CACGCCGGCGAGGCCGCTATCAGCCGCATGTTCATCGCCTACTGCATCAACGCAACCTACAGGCCAGACTTCACC GTCATCGGCAACCTGCTCGAGCTGTTCCACGAAACGTCCCGAGTCTTGGAACACCAGCCACGTACCGATCCGCTG ATCGCCGCCATCATCGAAACCATCACGGCAGATCCCGCCACGGCCCACAACCAGGCCATAGCGGACACACTTGGA TACAGCGTGGGATATCTGTCCCGGTACGCGCGCAAGCACAGCGGGCACACACTCGGCCAACTCATCAACGAGGAA AGGCTCCGACTCGGCGCCGAACTGCTCGTCACCACCGACGACACCATTGCCGAAATCACCCGAACCATTGGCTAC GAAAGTCCAGCCTATTTCCATAAACTCTTCCGCAGCCGCTACCTCATTACCCCCGACCGCTACCGCAACGACTTC CGTATCGCATTACGTTGCGGATGA Suitably, the AraC gene may encode a protein shown as SEQ ID NO: 40 or a sequence with at least 80% sequence identity to SEQ ID NO: 40. Suitably, the protein may comprise a sequence with at least 85%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 40. SEQ ID NO: 40 MERDAFRLPGLTAGDDNQYADHTLTGMAADAANVIAAGGPAPLTSFGTVAQAAHLNPDDGFGIIGHDLAHPSHLH RHDYMEITHAIAGTVLVWVEGETNVLTQGGTILIKPGARHLISPIIEYGQTPHEADILIKPELIRQCRIPILEAA GADRMFISWLDDDRQTHCLLAAGKHHAGEAAISRMFIAYCINATYRPDFTVIGNLLELFHETSRVLEHQPRTDPL IAAIIETITADPATAHNQAIADTLGYSVGYLSRYARKHSGHTLGQLINEERLRLGAELLVTTDDTIAEITRTIGY ESPAYFHKLFRSRYLITPDRYRNDFRIALRCGSuitably, the B. longum transitional strain comprises a MFS transporter and an AraC familytranscriptional regulator gene.Suitably, the B. longum transitional strain comprises a GH43_17, a MFS transporter and anAraC family transcriptional regulator gene. Suitably, the GH43_17, MFS transporter and AraC family transcriptional regulator genes are comprised in a gene cluster.. As used herein, a ‘gene cluster’ may refer to a group of genes that are located next to each other in a chromosome.Suitably, the B. longum transitional strain comprises each of a GH31, an ABC transporter, aLac-I type regulator, a MFS transporter and / or an AraC family transcriptional regulator gene.Suitably, the B. longum transitional strain comprises a GH43_17, a MFS transporter, an AraC,a GH31, an ABC transporter, and a Lac-I type regulator gene. Suitably, the GH43_17, MFS transporter, AraC family transcriptional regulator, GH31, ABC transporter, and Lac-I type regulator genes are comprised in aa gene cluster as described above.Suitably, the B. longum transitional strain further comprises a xylulose kinase gene and / or axylose isomerase gene. Suitably, the xylulose kinase gene and / or xylose isomerase genes are comprised in a gene cluster as defined above. Suitably, the xylulose kinase gene comprises SEQ ID NO: 41 or a sequence with at least 60% sequence identity to SEQ ID NO: 41. Suitably, the xylulose kinase gene comprises a sequence with at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 41. SEQ ID NO: 41 ATGACGAGAGTACTGGTTGCCGGCGTAGATACGTCAACTCAATCAACAAAGGTCCGCATTACGGACGC CGCCACCGGCGAACAGGTTCGGTTCGGGCAGGCCAAGCACCCGGATGGCACCTCGGTCAACCCGGAAT TCTGGTGGGAGGCCTTCACCAAGGCCGCCGAGCAGGCCGGCGGGCTTGACGATGTCGCGGCCCTCGCG GTTGGCGGCCAGCAGCATGGCATGGTCATTCTCGACAAGCAGGGCAACGTGATTCGCGATGCGATGCT CTGGAATGACACCAGTTCCGCCCCGCAGGCCGCCGCCCTGATCGACAAGCTCGGTGCAACTCCGGCCG AGGGCGACGAACCGGACGACGTGACCGCCCGCGGCAAGCAGCGCTGGGTCAAGGCCGTCGGGTCCTCC CCCGTCGCTTCCTACACGCTGACCAAGGTGGCGTGGGTGGCCGAGAACGAGCCTGAGAACGCCAAGAA GATTGCCGCCGTCTGTCTGCCGCACGATTGGCTGAGCTGGCGTATCGCCGGCTATGGCCCGGTGGCCG AGGGCGAGGACGCTCATCTCGAAGCCCTGTTCACCGACCGTTCCGACGCTTCCGGCACCATTTACTAC GATGCCGCGCATGACGAGTACCGCCGCGATCTCATCGCCATGGTGCTGACCCCCGCCGAGGGCGAGGA AGCCGCCAAGGCCCACGCCGACGCCATTGTGCTGCCCACCGTGCTGGGCCCGCATGAGGCAGCCGCCG TCAAGGCCGACCCCGCCATTGCCGGCAAGGACGTTGAAGGCGGCTGCATCATCGGCCCCGGCGGCGGA GACAATGCCATGGCCTCGCTGGGCCTCGGCATGGCCGTGGGCGATGTGTCCGTATCGCTCGGCACCTC CGGCGTGGCCGCGGCCATCGCTGAAAACCCGGTGTACGACCTGACCGGAGCGATTTCTGGCTTTGCCG ACTGCACCGGTCATTATCTGCCGCTTGCCTGCACCATCAACGGTTCGCGCATTCTGGACGCCGGTCGC GCCGCCCTTGGCGTGGACTACGACGAGCTGGCCGAACTGGCCTTTAAGGCCGAGCCGGGTGCCGGCGG CATCACCCTGGTGCCGTACTTCGACGGCGAGCGTACGCCGAACCGTCCGGACGCCACCGCCTCGCTGA CTGGCCTGACCCTGCACAACACCACCAAGGAGAATCTGGCTCGTGCGTTCGTCGAAGGCCTGCTGTGT TCCCAGCGCGACTGCCTCGAGCTGATTCGTTCGCTGGGTGCCGAGATCAACCGCATCCTGCTCATTGG CGGTGGCGCGAAGTCCGTGGCCATCCGCACGCTGGCCCCCTCAATCCTCGGCATGGACGTGACCCGTC CGGCCACCGACGAATATGTGGCCATCGGCGCCGCCCGTCAGGCCGCCTGGGTGCTGTCCGGCGAGGCC GAACCGCTGACCTGGCAACTCACCATCGAGGGCGTGGAGACCGGCGAGCCCACCGAAGCCGTGTACGA GGCATACGCCAAGGCGCGCGGCTGA Suitably, the xylulose kinase gene may encode a protein shown as SEQ ID NO: 42 or a sequence with at least 80% sequence identity to SEQ ID NO: 42. Suitably, the protein may comprise a sequence with at least 85%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 42. SEQ ID NO: 42 MTRVLVAGVDTSTQSTKVRITDAATGEQVRFGQAKHPDGTSVNPEFWWEAFTKAAEQAGGLDDVAALAVGGQQHG MVILDKQGNVIRDAMLWNDTSSAPQAAALIDKLGATPAEGDEPDDVTARGKQRWVKAVGSSPVASYTLTKVAWVA ENEPENAKKIAAVCLPHDWLSWRIAGYGPVAEGEDAHLEALFTDRSDASGTIYYDAAHDEYRRDLIAMVLTPAEG EEAAKAHADAIVLPTVLGPHEAAAVKADPAIAGKDVEGGCIIGPGGGDNAMASLGLGMAVGDVSVSLGTSGVAAA IAENPVYDLTGAISGFADCTGHYLPLACTINGSRILDAGRAALGVDYDELAELAFKAEPGAGGITLVPYFDGERT PNRPDATASLTGLTLHNTTKENLARAFVEGLLCSQRDCLELIRSLGAEINRILLIGGGAKSVAIRTLAPSILGMD VTRPATDEYVAIGAARQAAWVLSGEAEPLTWQLTIEGVETGEPTEAVYEAYAKARG Suitably, the xylose isomerase gene comprises SEQ ID NO: 43 or a sequence with at least 60% sequence identity to SEQ ID NO: 43. Suitably, the xylose isomerase gene comprises a sequence with at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 43. SEQ ID NO: 43 ATGGGTCTGTGGGATGTTGACAAGATCGAGTACGTCGGCCGCGCCAAAGGACCGAAGGAAGACTTCGCCTTCCAT TACTACGATGCCGACAAGGTCGTTGCCGGCAAGAAGATGAAGGATTGGCTGCGCTTCGGCGTTGCTTGGTGGCAC ACCTTCAACCAGGAACTGGTTGATCCGTTCGGCACCGGCACCGCGCACCGCCCGTACTACAAGTACACCGATCCG ATGGACCAGGCTCTGGCCAAGGTCGACTACGCCTTCGAGCTGTTCCAGAAGCTGGGCGTCGAGTACTTCTGCTTC CACGATCGTGACATCGCCCCCGAAGGCGACACCCTGCGCGAGACCAACGCCAACCTCGACAAGGTCGTTGACAAG ATCGACGAGAATATGAAGTCCACCGGTGTCAAGCTGCTGTGGAACACCTCCTCCCTGTTCACCAACCCGCGCTTC GTGTCCGGCGCCGCCACTTCTCCGTTCGCCGACATCTACGCCTACGCCGGTGGCCAGCTCAAGAAGAGCTTGGAG ATCGGCAAGCGCCTGGGCGCCGAGAACTACGTGTTCTGGGGTGGCCGCGAAGGCTACGAGAACCTGTGGAACACC GAGATGAAGCGCGAGACCGACCACATCGCCAAGTTCTTCCACATGTGCGCAGATTACGCCAAGGAAATCGGCTTT GAGGCCCAGTTCCTGATCGAGCCGAAGCCGAAGGAGCCGACGCTGCACCAGTACGACTTCGATGCCGCCACCGCC ATCGAGTTCCTGCGCAACCACGACCTGACCGACGTCTTCAAGCTGAACTTGGAAGGCAACCACGCCAACCTGGCC GGCCACACCTACCAGCACGAGATCCGCGTGGCCCGCGAGTCCGGCTTCCTCGGTTCCCTCGACGCCAACCAGGGC GACAAGCTCATCGGCTGGGATATGGACGAGTTCCCGACCGATCTGTACGAGACCGTCGCCGTCATGTGGGAAGTC CTGCAGGCCGGCTCCATCGGACCTCACGGTGGTCTGAACTTCGACGCCAAGCCGCGCCGTACCTCCTTCTACGAG GAGGACCTGTTCCGCTCCCACATCGCCGGCATGGATGCCTACGCCGCCGGCCTGCTGGTTGCCGACAAGATGAAC CAGGACGGCTTCATCCAGAATCTTCAGGCCGAGCGCTACAGCTCCTACGACTCCGGCATCGGCAAGGACATCGAC GAGGGCAACGTCACCTTGGCCGACCTCGAAGCCTACAGCCTCGACAAGCCGCAGTCCGAGCTCATCGCCGCCACC AAGTCCGATCACCTCGAGTCCGTCAAGGCCACCATCAACAACTACATCATTGATGCCCTGGCTGAGGTCGAGTGA Suitably, the xylulose isomerase gene may encode a protein shown as SEQ ID NO: 44 or a sequence with at least 80% sequence identity to SEQ ID NO: 44. Suitably, the protein may comprise a sequence with at least 85%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 44. SEQ ID NO: 44 MGLWDVDKIEYVGRAKGPKEDFAFHYYDADKVVAGKKMKDWLRFGVAWWHTFNQELVDPFGTGTAHRPYYKYTDP MDQALAKVDYAFELFQKLGVEYFCFHDRDIAPEGDTLRETNANLDKVVDKIDENMKSTGVKLLWNTSSLFTNPRF VSGAATSPFADIYAYAGGQLKKSLEIGKRLGAENYVFWGGREGYENLWNTEMKRETDHIAKFFHMCADYAKEIGF EAQFLIEPKPKEPTLHQYDFDAATAIEFLRNHDLTDVFKLNLEGNHANLAGHTYQHEIRVARESGFLGSLDANQG DKLIGWDMDEFPTDLYETVAVMWEVLQAGSIGPHGGLNFDAKPRRTSFYEEDLFRSHIAGMDAYAAGLLVADKMN QDGFIQNLQAERYSSYDSGIGKDIDEGNVTLADLEAYSLDKPQSELIAATKSDHLESVKATINNYIIDALAEVEHuman milk oligosaccharide (HMO)Suitably, the present B. longum transitional strain preferentially utilizes 3- fucosyllactose (3-FL) compared to other B. longum transitional strainsas demonstrated by a better growth, forexample as shown in the present Examples.Suitably, the present B. longum transitional strain may have a growth rate of at least 0.6 kwhen cultured in the presence of 3-FL. Suitably, the present B. longum transitional strain mayhave a growth rate of at least 0.7 k, at least 0.8 k or at least 0.9 k when cultured in the presence of 3-FL. Growth rate may be calculated by culturing a bacterium on a given substrate, or mixture of substrates, for a period of time and modelling the growth curve using a logistic growth model, to obtain the relative growth rate k. An illustrative method for determining growth rate is provided in the present Examples. Without wishing to be bound by theory, preferential growth on 3-FL is considered to be advantageous as levels of 3-FL rise in human breastmilk during the weaning period. Preferentially growth on 3-FL indicates that the present B. longum transitional strain may be particularly adapted to survive and grow in the microbiome during the weaning phase. Suitably, the present B. longum transitional strain comprises a glycosyl hydrolase family 25 (GH25) gene. Suitably, the GH25 gene comprises SEQ ID NO: 45 or a sequence with at least60% sequence identity to SEQ ID NO: 45. Suitably, the GH25 gene comprises a sequencewith at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 45. SEQ ID NO: 45 ATGAGCAATCCAACAAATGATGGTATCAACTTGAATTACCTCGCAAACGTGCGTCCCTCGTCGCGACAGCTTGTC TGGCAGCGTATGGAGATGTATGCCTTCATACACTTCGGCATGAATACCATGACAGACAGGGAATGGGGTCTTGGG CATGAGGATCCGGCGCTGTTCGATCCACAGAATGTAGATGTGGAACAGTGGATGGATGCGCTGGTGGCTGGTGGA ATGACTGGTGTCATCTTGACGTGCAAGCATCATGATGGATTCTGCCTGTGGCCATCGCGTTACACGCAGCATACC GTTGCCGCCTCGCCGTGGAGGGACGGAAAAGGGGATCTCGTTCGTGAGGTCAGTGAGTCCGCCAGACGTCATGGA CTGAAGTTCGGCGTATACCTGTCTCCGTGGGATCGAACCGAAGAATCCTATGGCAAAGGCAAGGCATATGACGAT TTCTACGTCGGACAATTGACTGAGTTGCTCACCCAGTACGGACCGATTTTCTCCGTATGGCTGGATGGTGCCAAT GGTGAGGGCAAGAACGGCAAGACTCAGTATTACGACTGGGATCGTTACTACAACGTCATTCGTTCGCTTCAACCC AATGCGGTGATATCCGTATGCGGTCCCGACGTTCGCTGGGCTGGAAATGAAGCCGGACATGTACGTGACAACGAA TGGAGTGTCGTGCCCCGACGACTGCGTTCGGCGGAACTGACTATGGAAAATTCACAGCAGGAGGACGATGCGTCC TTTGCTTCTACGGTTCGCTCTCAAGATGACGACCTTGGAAGTCGTGAGGCGGTTTCCGGATACGGGGATGACGTC TGTTGGTACCCAGCTGAGGTCGATACCTCCATTCGCCCTGGATGGTTCTATCACAAGTATGAAGACGACAAGGTC ATGAGCGCAGATCAGCTTTTTGACCTCTGGCTTTCCGCAGTCGGCGGTAATTCGTCTCTTCTGCTCAATATTCCT CCGTCTCCAGAAGGACTGTTCGCAGAACCGGATGTGGAGTCGCTCAAGGGGCTGGGAAGCCGTATCAATGAATTC CGCAAAGCATTGGCTTCGTCTTGTTGCGAGGTCAAGACCAGCAGCGCGGACGAAACTGCAATGCGACTTCTCGAT GGGAATCAGGACACGTATTGGTCTCCTGATGCCAATGACGTGGCCCCTGCCGTCACGCTCACTTTCCCGCAGCTG ACGACGATCAATGCCGTTGTGGTTGAAGAGGCCATAGAGTATGGGCAGCGCATTGAACATATGCGCGTTACTGGT GTGCTATCTGATGGTACTGAGTGTGTACTCGGCCAGTTCGGCACAGTGGGATACCGCAGGATACTCCGCTTCGAC GATGTCGAAGTATCTTCGGTTACCCTACATGTGGATGATTCAAGGTTCACGCCAATGATCAGCCGTGCAGCTGCG GTGCGGATATAA Suitably, the GH25 gene may encode a protein shown as SEQ ID NO: 46 or a sequence with at least 80% sequence identity to SEQ ID NO: 46. Suitably, the protein may comprise a sequence with at least 85%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 46. SEQ ID NO: 46 MSNPTNDGINLNYLANVRPSSRQLVWQRMEMYAFIHFGMNTMTDREWGLGHEDPALFDPQNVDVEQWMDALVAGG MTGVILTCKHHDGFCLWPSRYTQHTVAASPWRDGKGDLVREVSESARRHGLKFGVYLSPWDRTEESYGKGKAYDD FYVGQLTELLTQYGPIFSVWLDGANGEGKNGKTQYYDWDRYYNVIRSLQPNAVISVCGPDVRWAGNEAGHVRDNE WSVVPRRLRSAELTMENSQQEDDASFASTVRSQDDDLGSREAVSGYGDDVCWYPAEVDTSIRPGWFYHKYEDDKV MSADQLFDLWLSAVGGNSSLLLNIPPSPEGLFAEPDVESLKGLGSRINEFRKALASSCCEVKTSSADETAMRLLD GNQDTYWSPDANDVAPAVTLTFPQLTTINAVVVEEAIEYGQRIEHMRVTGVLSDGTECVLGQFGTVGYRRILRFD DVEVSSVTLHVDDSRFTPMISRAAAVRI Suitably, the present B. longum transitional strain comprises a glycosyl hydrolase family 95 (GH95) gene. Suitably, the GH95 gene comprises SEQ ID NO: 47 or a sequence with at least 60% sequence identity to SEQ ID NO: 47. Suitably, the GH95 gene comprises a sequence with at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 47. SEQ ID NO: 47 ATGAAACTCACATTCGATGGAATCTCTTCGTGCTGGGAAGAAGGCATCCCGCTCGGCAACGGACGCATGGGAGCG GTCCTGTGTTCCGAACCGGAAACCGACGTGCTGTATCTCAACGACGACACCCTTTGGTCAGGATATCCACACGCG GAAACCTCGCCGGTGACGCCGGAGATTGTGGCCAAGGCACGCCAGGCGTCGTTGCAGGACGACTACACCGCCGCC ACGCGAATCATCAAGGAAGCCACACTGCAGGAAAAGGACGAACAGATTTACGAGCCATTCGGAACGGCCCGTATT CAGTACTCGACCCCTGCAGACGGCCGTGAGAGCATGAAACGCCAGCTGGATCTTGCAAGGGCGCTCGCCGGTGAA ACATTCCAGATGGGTGATGCCAACGTTCATGTCGACGCATGGTGCAGCGAGCCTGATGACCTGTTGGTCTACAGG ATGTCATCGGATGCGCCGGTTGATGTGAACATCAGTGTCGCCGGCACTTTCCTCAAACAATCGCGCGCCTCGTTG GAAACGGTATCCGACGGTCATCGGGCCACACTCGTCGTCATGGGCCGGATGCCTGGACTCAACATCGGGCTCCTC CCTCATCCTTCCGAACATCCTTGGGAAGATGAGCAGGACGGAACCGGAATGGCGTACGCCGGTGCGTTCTCCCTT ACCGTCACAGGTGGCGACATCAATGTGGACGACAACAGTCTGCAATGTTCGCACATCACCGGATTATCGCTCCGC TTCCGCAGTATGAGCGGATTCAAGGGAAGCGACCAGCAGCCGGAACGAAGCATGACGGTTATCGCCGACCATCTG GAGAAAACCATCGACGAGTGGTCGACCGACCTGCAGACCATGCTCGACCGCCATATCGCGGACTACCGCAGATAT TTCGACAGGGTGGCCATCCATCTCGGTTCAGCCCATGATGACGATACGGAACTACCGTTCTCGGCGATCCTTCGC TCGGATGAGAACAAAGAACCGCATCGTCTGGAGATGCTGGCGGAGGCAATGTTCGATTTCGGCCGGTATATGCTT ATCTCCTCGTCCAGGCCACACACCCAGCCGGCGAATCTGCAGGGGATTTGGAACCATAAGGACTTCCCAAACTGG TACAGCGCCTACACGACGAACATCAACGTCGAGATGAACTATTGGATGACCGGCCCCTGCGCGCTCAAGGAGCTC ATCGAGCCGCTCGTCTCCATGAATGAGGAGCTGCTGGCACCGGGGCACGATGCCGCTGACAGGATTCTCGGCTGC CGAGGATCGGCTGTCTTCCATAATGTCGATCTCTGGCGTAGGGCCCTTCCTGCGAACGGCGATCCGATGTGGGCG TTCTGGCCGTTCGGCCAGGCATGGATGTGCCGGAACCTGTTCGATGAATATCTGTTCAACCAGGATGCATCGTAC CTGGCCCGCATCTGGCCGATCATGCGGGACAACGCGCGATTCTGCATGGATTTCCTATCGGAGACAGAGCATGGG CTGGCCCCGTCCCCTGCAACATCACCGGAGAACTGTTTCCTGGTGAACGGAGAACCGGTATCCGTTGCGCAAAGC AGTGAGAATGCCACGGCCATCGTGCGTAATCTGCTTGATGATTTGATTCAGGCTTCTCACGATCTGGAAAACCTT GACGAAGAGGACAGAAATCTGGTCCGTGAAGCGGAATCCGTCCGTTCCCAACTGGCTGAAACGCGATTGGGAGCT GATGGAAGAGTCCTTGAATGGAACGACGAATTCATCGAATCCGATCCACAGCACCGCCATCTGTCCCACCTTTAC GAACTGCATCCTGGTGCAGGCATCACGTCTAAGACTCCGCGTCTGGAGGAAGCCGCGAGAAAATCCCTCGAAGTG CGTGGCGATGATGGTTCCGGTTGGAGCATCGTATGGCGCATGATCATGTGGGCACGTCTGCGTGATGCGGAACAC GCCAAACGAATCATAGGCATGTTCCTACGGCCGGTGGATGCGAACGCTGAAACCAATCTGCTGGGCGGAGGAGTG TACGACAGCGGATTATGCGCCCACCCGCCGTTCCAGATCGACGGGAACCTTGGATTCCCGGCGGCCTTGTCGGAG ATGCTCGTCCAAAGCCACGATGGCTGGATTCGCGTTCTTCCGGCCCTGCCGGAGGATTGGCATGAGGGAAGCTTC CATGCGCTCCGCGCAAGAGGTGGAATCCAAGTGGATGCGACCTGGACGGATCAGACAGTGGAATATACGTTGCGC TGTTCGAAGCCCACGGAGATTACGCTGAACGTTCTGGGGACTGATATGGGACGTGTCGCATTGTCTCCGGATAAG CCATTCAAGGGAACCATCCGGCGTTAA Suitably, the GH95 gene may encode a protein shown as SEQ ID NO: 48 or a sequence with at least 80% sequence identity to SEQ ID NO: 48. Suitably, the protein may comprise a sequence with at least 85%, at least 90%, at least 95%, at least 98% or at least 99% sequence identity to SEQ ID NO: 48. SEQ ID NO: 48 MKLTFDGISSCWEEGIPLGNGRMGAVLCSEPETDVLYLNDDTLWSGYPHAETSPVTPEIVAKARQASLQDDYTAA TRIIKEATLQEKDEQIYEPFGTARIQYSTPADGRESMKRQLDLARALAGETFQMGDANVHVDAWCSEPDDLLVYR MSSDAPVDVNISVAGTFLKQSRASLETVSDGHRATLVVMGRMPGLNIGLLPHPSEHPWEDEQDGTGMAYAGAFSL TVTGGDINVDDNSLQCSHITGLSLRFRSMSGFKGSDQQPERSMTVIADHLEKTIDEWSTDLQTMLDRHIADYRRY FDRVAIHLGSAHDDDTELPFSAILRSDENKEPHRLEMLAEAMFDFGRYMLISSSRPHTQPANLQGIWNHKDFPNW YSAYTTNINVEMNYWMTGPCALKELIEPLVSMNEELLAPGHDAADRILGCRGSAVFHNVDLWRRALPANGDPMWA FWPFGQAWMCRNLFDEYLFNQDASYLARIWPIMRDNARFCMDFLSETEHGLAPSPATSPENCFLVNGEPVSVAQS SENATAIVRNLLDDLIQASHDLENLDEEDRNLVREAESVRSQLAETRLGADGRVLEWNDEFIESDPQHRHLSHLY ELHPGAGITSKTPRLEEAARKSLEVRGDDGSGWSIVWRMIMWARLRDAEHAKRIIGMFLRPVDANAETNLLGGGV YDSGLCAHPPFQIDGNLGFPAALSEMLVQSHDGWIRVLPALPEDWHEGSFHALRARGGIQVDATWTDQTVEYTLR CSKPTEITLNVLGTDMGRVALSPDKPFKGTIRRSuitably, the present B. longum transitional strain may comprise a GH25 and a GH95 gene asdefined herein. HMO mixtureThe composition or combination of the invention comprises a HMO mixture.In some embodiments, the HMO mixture consists of 2’-FL, DFL, LNT, 6SL, and 3SL.In some embodiments, the HMO mixture consists of 2’-FL, DFL, LNT, 6SL, 3SL and 3-FL.In some embodiments, the HMO mixture consists of 2’-FL, DFL, LNT, 6SL, 3SL and LNnT.In some embodiments, the HMO mixture consists of 2’-FL, DFL, LNT, 6SL, 3SL, 3-FL andLNnT.In some embodiments, the HMO mixture consists of LNFP-I, 2’-FL, DFL, LNT, 6SL, and 3SL.In some embodiments, the HMO mixture consists of LNFP-I, 2’-FL, DFL, LNT, 6SL, 3SL and3-FL.In some embodiments, the HMO mixture consists of LNFP-I, 2’-FL, DFL, LNT, 6SL, 3SL andLNnT.In some embodiments, the HMO mixture consists of LNFP-I, 2’-FL, DFL, LNT, 6SL, 3SL, 3-FL and LNnT.In one embodiment, the HMO mixture comprises 2’-FL in an amount of from 16 wt% to 85wt%. Suitably, the HMO mixture may comprise 2’-FL in an amount of from 31 wt% to 82 wt%,preferably from 41wt% to 70 wt%. Suitably, the HMO mixture may comprise 2’-FL in an amountof from 16 wt% to 69 wt%, preferably from 22 wt% to 59 wt%. Suitably, the HMO mixture maycomprise 2’-FL in an amount of from 34 wt% to 85 wt%, preferably from 40 wt% to 71 wt%.Suitably, the HMO mixture may comprise 2’-FL in an amount of from 20 wt% to 60 wt%,preferably from 22 wt% to 55 wt%.In one embodiment, the HMO mixture comprises LNT in an amount of from 4 wt% to 40 wt%.Suitably, the HMO mixture may comprise LNT in an amount of from 10 wt% to 27 wt%,preferably from 14 wt% to 23 wt%. Suitably, the HMO mixture may comprise LNT in an amountof from 9 wt% to 24 wt%, preferably 12 wt% to 21 wt%. Suitably, the HMO mixture maycomprise LNT in an amount of from 10 wt% to 40 wt%, preferably 12 wt% to 26 wt%. Suitably,the HMO mixture may comprise LNT in an amount of from 4 wt% to 30 wt%, preferably 6 wt%to 20 wt%.In one embodiment, the HMO mixture comprises DFL in an amount of from 1 wt% to 14 wt%.Suitably, the HMO mixture may comprise DFL in an amount of from 4 wt% to 11 wt%,preferably from 6 wt% to 10 wt%. Suitably, the HMO mixture may comprise DFL in an amountof from 2 wt% to 10 wt%, preferably from 3 wt% to 8 wt%. Suitably, the HMO mixture maycomprise DFL in an amount of from 4 wt% to 14 wt %, preferably from 5 wt% to 10 wt%.Suitably, the HMO mixture may comprise DFL in an amount of from 1 wt% to 12 wt %,preferably from 2 wt% to 8 wt%.In one embodiment, the HMO mixture comprises 6SL and 3SL combined in an amount of from7 wt% to 34 wt%. Suitably, the HMO mixture may comprise 6SL and 3SL combined in anamount of from 9 wt% to 34 wt%, preferably from 11 wt% to 29 wt%. Suitably, the HMO mixturemay comprise 6SL and 3SL combined in an amount of from 8 wt% to 26 wt%, preferably from11 wt% to 22 wt%. Suitably, the HMO mixture may comprise 6SL and 3SL combined in anamount of from 9 wt% to 31 wt%, preferably from 10 wt% to 28 wt%. Suitably, the HMO mixturemay comprise 6SL and 3SL combined in an amount of from 7 wt% to 23 wt%, preferably from8 wt% to 22 wt%.In one embodiment, the HMO mixture comprises 3-FL in an amount of from 10 wt% to 50 wt%.Suitably, the HMO mixture may comprise 3-FL in an amount of from 18 wt% to 50 wt%,preferably from 11 wt% to 43 wt%. Suitably, the HMO mixture may comprise 3-FL in an amountof from 10 wt% to 50 wt%, preferably from 13 wt% to 46 wt%.In one embodiment, the HMO mixture comprises LNnT in an amount of from 6 wt% to 30 wt%.Suitably, the HMO mixture may comprise LNnT in an amount of from 6 wt% to 30 wt%,preferably from 7 wt% to 22 wt%. Suitably, the HMO mixture may comprise LNnT in an amountof from 3 wt% to 25 wt%, preferably from 5 wt% to 20 wt%.In some embodiments, LNFP-I is present in a total amount of from 10 mg / L to 5000 mg / L ofthe composition or combination according to the invention or of from 0.01 g / 100 g to 4 g / 100g of the nutritional composition or combination according to the invention. In some embodiments, LNFP-I is present in a total amount of from 25 mg / L to 4000 mg / L ofthe composition or combination according to the invention or of from 0.02 g / 100 g to 3.75g / 100 g of the nutritional composition or combination according to the invention. Suitably,LNFP-I is present in a total amount of from 50 mg / L to 2500 mg / L, for example from 60 mg / L to 2000 mg / L, for example from 80 mg / L to 1500 mg / L, for example from 100 mg / L to 1000 mg / L, for example from 200 mg / L to 800 mg / L of the composition or combination according to the invention. Suitably, LNFP-I is present in a total amount of from 0.04 g / 100 g to 2 g / 100 g,for example from 0.05 g / 100 g to 1.6 g / 100 g, for example from 0.06 to 1.2 g / 100g, for examplefrom 0.07 g / 100 g to 0.8 g / 100 g, for example from 0.1 g / 100g to 0.7 g / 100g of the compositionor combination (dry weight). In one embodiment, the composition or combination comprises from 0.015 wt.% to 3.8 wt.%,preferably from 0.08 wt.% to 1.2 wt.%, of lacto-N-fucopentaose I (LNFP-I) of the total wt.% ofthe composition or combination.In some embodiments, the HMO mixture consists essentially of:i. 31 wt% to 82 wt% of 2’-FL;ii. 10 wt% to 27 wt% of LNT;iii. 4 wt% to 11 wt% of DFL; andiv. 9 wt% to 34 wt% of 6SL and 3SL combined.In some preferred embodiments, the HMO mixture consists essentially of:i. 41 wt% to 70 wt% of 2’-FL;ii. 14 wt% to 23 wt% of LNT;iii. 6 wt% to 10 wt% of DFL; andiv. 11 wt% to 29 wt% of 6SL and 3SL combined.In some embodiments, the HMO mixture consists essentially of:i. 16 wt% to 69 wt% of 2’-FL;ii. 9 wt% to 24 wt% of LNT;iii. 2 wt% to 10 wt% of DFL;iv. 8 wt% to 26 wt% of 6SL and 3SL combined; andv. 18 wt% to 50 wt% of 3-FL.In some preferred embodiments, the HMO mixture consists essentially of:i. 22 wt% to 59 wt% of 2’-FL;ii. 12 wt% to 21 wt% of LNT;iii. 3 wt% to 8 wt% of DFL;iv. 11 wt% to 22 wt% of 6SL and 3SL combined; andv. 11 wt% to 43 wt% of 3-FL.In some embodiments, the HMO mixture consists essentially of:i. 34 wt% to 85 wt% of 2’-FL;ii. 10 wt% to 40 wt% of LNT;iii. 4 wt% to 14 wt% of DFL;iv. 9 wt% to 31 wt% of 6SL and 3SL combined; andv. 6 wt% to 30 wt% of LNnT.In some preferred embodiments, the HMO mixture consists essentially of:i. 40 wt% to 71 wt% of 2’-FL;ii. 12 wt% to 26 wt% of LNT;iii. 5 wt% to 10 wt% of DFL; andiv. 10 wt% to 28 wt% of 6SL and 3SL combined; andv. 7 wt% to 22 wt% of LNnT.In some embodiments, the HMO mixture consists essentially of:i. 20 wt% to 60 wt% of 2’-FL;ii. 4 wt% to 30 wt% of LNT;iii. 1 wt% to 12 wt % of DFL;iv. 7 wt% to 23 wt% of 6SL and 3SL combined;v. 10 wt% to 50 wt% of 3-FL; andvi. 3 wt% to 25 wt% of LNnT.In some preferred embodiments, the HMO mixture consists essentially of:i. 22 wt% to 55 wt% of 2’-FL;ii. 6 wt% to 20 wt% of LNT;iii. 2 wt% to 8 wt % of DFL;iv. 8 wt% to 22 wt% of 6SL and 3SL combined;v. 13 wt% to 46 wt% of 3-FL andvi. 5 wt% to 20 wt% of LNnT.In some embodiments, the HMO mixture consists or consists essentially of:i. 20 wt% to 46 wt% of 2FL;ii. 11 wt% to 17 wt% of LNT;iii. 2 wt% to 7 wt% of DFL;iv. 9 wt% to 21 wt% of 6SL and 3SL combined;v. 9 wt% to 34 wt% of 3FL; andvi. 5 wt% to 32 wt% of LNFP-I.In some preferred embodiments, the HMO mixture consists or consists essentially of:i. 22 wt% to 42 wt% of 2FL;ii. 12 wt% to 15 wt% of LNT;iii. 3 wt% to 6 wt% of DFL;iv. 9 wt% to 19 wt% of 6SL and 3SL combined;v. 11 wt% to 32 wt% of 3FL; andvi. 10 wt% to 19 wt% of LNFP-I.In some embodiments, the HMO mixture consists or consists essentially of:i. 27 wt% to 41 wt% of 2FL;ii. 8 wt% to 15 wt% of LNT;iii. 4 wt% to 6 wt% of DFL;iv. 8 wt% to 18 wt% of 6SL and 3SL combined;v. 13 wt% to 21 wt% of LNnT; andvi. 7 wt% to 33 wt% of LNFP-I.In some preferred embodiments, the HMO mixture consists or consists essentially of:i. 32 wt% to 39 wt% of 2FL;ii. 10 wt% to 14 wt% of LNT;iii. 4 wt% to 6 wt% of DFL;iv. 7 wt% to 15 wt% of 6SL and 3SL combined;v. 16 wt% to 20 wt% of LNnT; andvi. 11 wt% to 23 wt% of LNFP-I.In some embodiments, the HMO mixture consists or consists essentially of:i. 29 wt% to 40 wt% of 2FL;ii. 8 wt% to 13 wt% of LNT;iii. 3 wt% to 11 wt % of DFL;iv. 3 wt% to 15 wt% of 6SL and 3SL combined;v. 11 wt% to 35 wt% of 3FL;vi. 1 wt% to 18 wt% of LNnT; andvii. 2 wt% to 24 wt% of LNFP-I.In some preferred embodiments, the HMO mixture consists or consists essentially of:i. 32 wt% to 39 wt% of 2FL;ii. 9 wt% to 12 wt% of LNT;iii. 3 wt% to 11 wt % of DFL;iv. 4 wt% to 15 wt% of 6SL and 3SL combined;v. 12 wt% to 35 wt% of 3FL;vi. 1 wt% to 17 wt% of LNnT; andvii. 4 wt% to 14 wt% of LNFP-I.When the composition or combination is in liquid form, the total HMO concentration is typicallyin the range from 0.5 to 10 g / L, preferably in the range from 1 to 7.5 g / L. Specific examplesof the concentration level of total HMO, when the composition or combination is in liquid form,include 1 to 5 g / L, 1 to 4 g / L, 2 to 5 g / L, 1 to 3 g / L or 2 to 4 g / L.When the composition or combination is in solid form, the total HMO concentration is typicallyin the range from 0.35 to 7 wt% (g total HMO / 100 g dry composition), preferably in the range from 0.35 to 5 wt%. Specific examples of the concentration level of total HMO, when the composition or combination is in dry form, include 0.5 to 3.5 wt% (g total HMO per 100 g dry composition), 0.5 to 2.5 wt%, 1 to 3.5 wt%, 0.5 to 2 wt% or 1 to 2.5 wt%.Suitably, the B. longum transitional microorganism is capable of metabolising one or moreHMOs of the HMO mixture. Suitably, the B. longum transitional microorganism is capable ofmetabolising the HMOs contained in the HMO mixture. Suitably, the HMO mixture may becapable of promoting growth and / or survival of the B. longum transitional strain as describedherein. Bifidobacterium longum subsp. infantisBifidobacterium longum is a bacterium of the Bifidobacterium genus which is present in thehuman gastrointestinal tract. In 2002, three previously distinct species of Bifidobacterium, B.infantis, B. longum, and B. suis, were unified into a single species named B. longum with thebiotypes infantis, longum, and suis, respectively (Sakata, S., et al., 2002. International journalof systematic and evolutionary microbiology, 52(6), pp.1945-1951).Any suitable Bifidobacterium longum subsp. infantis strain may be used in the presentinvention. Such strains will be well-known to the skilled person. Suitable strains includeBifidobacterium longum subsp. infantis LMG 11588 (also known as Bifidobacterium longumsubsp. infantis NCC3039 or Bifidobacterium longum subsp. infantis ATCC 17930) andBifidobacterium longum subsp. infantis ATCC 15697 (also known as Bifidobacterium longumsubsp. infantis NCC 3078).The Bifidobacterium longum subsp. infantis may be a strain having at least 99% (suitably, atleast 99.9%) ANI to Bifidobacterium longum subsp. infantis strain known to the skilled person.Suitably, the Bifidobacterium longum subsp. infantis has at least 99% (suitably, at least 99.1%,at least 99.2%, at least 99.3%, at least 99.4%, at least 99.5%, at least 99.6%, at least 99.7%,at least 99.8%, at least 99.9%) ANI to Bifidobacterium longum subsp. infantis LMG 11588(also known as Bifidobacterium longum subsp. infantis NCC3039 or Bifidobacterium longumsubsp. infantis ATCC 17930). Preferably, the Bifidobacterium longum subsp. infantis has atleast 99.9% ANI to Bifidobacterium longum subsp. infantis LMG 11588.An example of a microorganism genome that has at least 99.9% ANI with B. longum subsp.infantis LMG 11588 can be found in PATRIC (https: / / www.patricbrc.org), genome ID1678.111. Hence, suitably the B. longum subsp. infantis having the PATRIC genome ID1678.111 may be used in the present invention.Bifidobacterium longum subsp. infantis LMG 11588 is sold by the Belgian CoordinatedCollections of Microorganisms (BCCM) under the LMG accession number LMG 11588.Bifidobacterium longum subsp. infantis ATCC 15697 is sold by the American Type CultureCollection (ATCC) under the accession number ATCC 15697.The composition or combination according to the invention may contain from 103to 1012cfuof Bifidobacterium longum subsp. infantis, more preferably between 107 and 1012 cfu such asbetween 108 and 1010 cfu of Bifidobacterium longum subsp. infantis per g of composition orcombination on a dry weight basis. Suitably, the Bifidobacterium longum subsp. infantis isadministered to the subject in an amount of at least about 106cfu / day, at least about 107cfu / day, or at least about 108 cfu / day. Suitably, the Bifidobacterium longum subsp. infantis isadministered to the subject in an amount of about 1012cfu / day or less, about 1011cfu / day or less, or about 1010cfu / day or less.In one embodiment, the Bifidobacterium longum subsp. infantis is viable.Bifidobacterium lactisAny suitable Bifidobacterium animalis subsp. lactis (B. lactis) strain may be used in the presentinvention. Such strains will be well-known to the skilled person. Suitable strains include Bifidobacterium lactis CNCM 1-3446. The Bifidobacterium lactis may be a strain having at least 99% (suitably, at least 99.9%) ANIto Bifidobacterium lactis strain known to the skilled person.Suitably, the Bifidobacterium lactis has at least 99% (suitably, at least 99.1%, at least 99.2%, at least 99.3%, at least 99.4%, at least 99.5%, at least 99.6%, at least 99.7%, at least 99.8%, at least 99.9%) ANI to Bifidobacterium lactis CNCM 1-3446. Preferably, the Bifidobacterium lactis has at least 99.9% ANI to Bifidobacterium lactis CNCM 1-3446.Bifidobacterium lactis CNCM 1-3446 was deposited with the Collection Nationale de Culturesde Microorganismes (CNCM), Institut Pasteur (INSTITUT PASTEUR, 25 RUE DU DOCTEURROUX, F-75724 PARIS CEDEX 15, FRANCE) by NESTEC S.A. (NESTEC S.A., AVENUE NESTLE 55, CH-1800 VEVEY) according to the Budapest Treaty on 7thJune 2005 receivingthe deposit number CNCM 1-3446.The composition or combination according to the invention may contain from 103to 1012cfu of Bifidobacterium lactis, more preferably between 107and 1012cfu such as between 108and1010 cfu of Bifidobacterium lactis per g of composition or combination on a dry weight basis.Suitably, the Bifidobacterium lactis is administered to the subject in an amount of at least about106cfu / day, at least about 107cfu / day, or at least about 108cfu / day. Suitably, theBifidobacterium lactis is administered to the subject in an amount of about 1012 cfu / day or less,about 1011cfu / day or less, or about 1010cfu / day or less. In one embodiment, the Bifidobacterium lactis is viable. Therapeutic usePreventing, reducing the risk of and / or treating an infectionIn a further aspect, the invention provides a composition comprising a Bifidobacterium longumtransitional microorganism and a HMO mixture consisting of 2'-fucosyllactose (2’-FL),difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT) for use in preventing, reducing the risk of and / or treating an infection in asubject, wherein the Bifidobacterium longum transitional microorganism has an AverageNucleotide Identity (ANI) of at least 98% with CNCM I-5942 and / or has at least one identifyingcharacteristic of the B. longum transitional strain deposited under deposit number CNCM I-5942. In a further aspect, the invention provides a composition comprising a Bifidobacterium longumtransitional microorganism, Bifidobacterium longum subsp. infantis and a HMO mixtureconsisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'- sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I),3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT) for use in preventing, reducing therisk of and / or treating an infection in a subject, wherein the Bifidobacterium longum transitionalmicroorganism has an Average Nucleotide Identity (ANI) of at least 98% with CNCM I-5942and / or has at least one identifying characteristic of the B. longum transitional strain depositedunder deposit number CNCM I-5942. In a further aspect, the invention provides a composition comprising a Bifidobacterium longumtransitional microorganism, Bifidobacterium longum subsp. infantis, Bifidobacterium lactis anda HMO mixture consisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose(LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I(LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT) for use in preventing,reducing the risk of and / or treating an infection in a subject, wherein the Bifidobacteriumlongum transitional microorganism has an Average Nucleotide Identity (ANI) of at least 98%with CNCM I-5942 and / or has at least one identifying characteristic of the B. longumtransitional strain deposited under deposit number CNCM I-5942. In a further aspect, the invention provides a nutritional composition comprising aBifidobacterium longum transitional microorganism and a HMO mixture consisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT) for use in preventing, reducing the risk of, and / ortreating an infection in a subject, wherein the Bifidobacterium longum transitionalmicroorganism has an Average Nucleotide Identity (ANI) of at least 98% with CNCM I-5942and / or has at least one identifying characteristic of the B. longum transitional strain depositedunder deposit number CNCM I-5942. In a further aspect, the invention provides a nutritional composition comprising aBifidobacterium longum transitional microorganism, Bifidobacterium longum subsp. infantisand a HMO mixture consisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT) for use inpreventing, reducing the risk of, and / or treating an infection in a subject, wherein theBifidobacterium longum transitional microorganism has an Average Nucleotide Identity (ANI)of at least 98% with CNCM I-5942 and / or has at least one identifying characteristic of the B.longum transitional strain deposited under deposit number CNCM I-5942.In a further aspect, the invention provides a nutritional composition comprising aBifidobacterium longum transitional microorganism, Bifidobacterium longum subsp. infantis,Bifidobacterium lactis, and a HMO mixture consisting of 2'-fucosyllactose (2’-FL),difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT) for use in preventing, reducing the risk of, and / or treating an infection in asubject, wherein the Bifidobacterium longum transitional microorganism has an AverageNucleotide Identity (ANI) of at least 98% with CNCM I-5942 and / or has at least one identifyingcharacteristic of the B. longum transitional strain deposited under deposit number CNCM I-5942. In a further aspect, the invention provides the use of a composition according to the inventionfor the manufacture of a medicament for preventing, reducing the risk of and / or treating aninfection in a subject.In a further aspect, the invention provides the use of a nutritional composition according to theinvention for the manufacture of a medicament for preventing, reducing the risk of and / ortreating an infection in a subject.In a further aspect, the invention provides a method of preventing, reducing the risk of and / ortreating an infection in a subject, wherein the method comprises administering a compositionaccording to the invention to the subject.In a further aspect, the invention provides a method of preventing, reducing the risk of and / ortreating an infection in a subject, wherein the method comprises administering a nutritionalcomposition according to the invention to the subject.Preferably, the composition or nutritional composition is for use in preventing and / or reducing the risk of an infection in a subject.The invention also provides a combination of a Bifidobacterium longum transitionalmicroorganism and a HMO mixture for use in preventing, reducing the risk of and / or treatingan infection in a subject; wherein the HMO mixture consists of 2'-fucosyllactose (2’-FL),difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), and whereinthe Bifidobacterium longum transitional microorganism has an Average Nucleotide Identity(ANI) of at least 98% with CNCM I-5942 and / or has at least one identifying characteristic ofthe B. longum transitional strain deposited under deposit number CNCM I-5942.The invention also provides a combination of a Bifidobacterium longum transitionalmicroorganism, Bifidobacterium longum subsp. infantis and a HMO mixture for use inpreventing, reducing the risk of and / or treating an infection in a subject; wherein the HMOmixture consists of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT),6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally 3-fucosyllactose (3-FL) and / orlacto-N-neotetraose (LNnT) and wherein the Bifidobacterium longum transitionalmicroorganism has an Average Nucleotide Identity (ANI) of at least 98% with CNCM I-5942and / or has at least one identifying characteristic of the B. longum transitional strain depositedunder deposit number CNCM I-5942. In a further aspect, the invention provides a combination of a Bifidobacterium longumtransitional microorganism, Bifidobacterium longum subsp. infantis, Bifidobacterium lactis,and a HMO mixture for use in preventing, reducing the risk of and / or treating an infection in asubject; wherein the HMO mixture consists of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL),lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally 3- fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), and wherein the Bifidobacteriumlongum transitional microorganism has an Average Nucleotide Identity (ANI) of at least 98%with CNCM I-5942 and / or has at least one identifying characteristic of the B. longumtransitional strain deposited under deposit number CNCM I-5942. In a further aspect, the invention provides the use of a combination according to the inventionfor the manufacture of a medicament for preventing, reducing the risk of and / or treating aninfection in a subject.In a further aspect, the invention provides a method of preventing, reducing the risk of and / ortreating an infection in a subject, wherein the method comprises administering a combinationaccording to the invention to the subject.Preferably, the composition or nutritional composition is for use in preventing and / or reducing the risk of an infection in a subject.The Bifidobacterium longum transitional microorganism may be a Bifidobacterium longumtransitional microorganism as described herein.The HMO mixture may be a HMO mixture as described herein.The Bifidobacterium longum subsp. infantis may be a Bifidobacterium longum subsp. infantisas described herein.The Bifidobacterium lactis may be a Bifidobacterium lactis as described herein.The combination (e.g. of a Bifidobacterium longum transitional microorganism and a HMOmixture) may be provided in any form as described herein. For example, the combination maybe provided in a composition as described herein.The B. longum transitional microorganism and HMO mixture may be administered separately,simultaneously or sequentially.Suitably, the B. longum transitional microorganism and HMO mixture may be administered ina combined composition.The B. longum transitional microorganism, HMO mixture, Bifidobacterium longum subsp.infantis and / or Bifidobacterium lactis may be administered separately, simultaneously orsequentially.Suitably, the B. longum transitional microorganism, HMO mixture, Bifidobacterium longumsubsp. infantis and Bifidobacterium lactis may be administered in a combined composition.Suitably, a combination of a B. longum transitional microorganism (and optionallyBifidobacterium longum subsp. infantis and / or Bifidobacterium lactis) and a HMO mixture maybe referred to as a “synbiotic”. “Infection”, as used herein, may refer to a disease or disorder caused by an infectious agent or pathogen (including symptoms thereof). “Preventing”, as used herein, may refer to administering the composition and / or combinationand / or prebiotic of the invention to a subject who has not yet contracted an infection and / orwho is not showing any symptoms of the infection to prevent or impair the cause of the disease or to reduce or prevent development of at least one symptom associated with the disease. The subject may have a predisposition for, or be thought to be at risk of developing, the disease. “Reducing the risk of an infection”, may refer to administering the composition and / or combination and / or prebiotic of the invention to a subject who has not yet contracted aninfection and / or who is not showing any symptoms of the infection to reduce the likelihood ofthe infant or young child developing a disease caused by infectious agent or pathogen. The administration may prevent or impair the cause of the disease or reduce or prevent development of at least one symptom associated with the disease. The subject may have a predisposition for, or be thought to be at risk of developing, the disease. By the expressions “treating” or “treatment”, it is meant a decrease of the duration and / or of the severity of a physical state, a condition or their consequences (e.g. a decrease orelimination of symptoms of the condition). Treatment also encompasses to reduce, alleviateor eliminate one or more symptoms associated with the disease, disorder or condition which is being treated and / or to slow down, reduce or block the progression of the disease, disorder or condition which is being treated. The prevention and / or the treatment of a physical state, a condition or their consequences can occur during the treatment (i.e. during the administration of the composition of the present invention, either immediately after the start of the administration or some time after, e.g. some days or weeks after the start). But it can also encompass the prevention and / or the treatment later in life. The term “later in life” encompasses the effect after the termination of the intervention or treatment. The effect “later in life” can be from 1 week to several months, or even years, for example from 2 to 4 weeks, from 2 to 6 weeks, from 2 to 8 weeks, from 1 to 6 months or from 2 to 12 months. Suitably, the effect “later in life” can be from 12 months to 12 years, such as from 2 years to 10 years, or from 4 years to 5 years, after the termination ofthe intervention or treatment. Suitably, the effect “later in life” lasts until the subject is at least5 years of age, such as at least 10 years of age, at least 20 years of age or at least 30 years of age. The present use to prevent and / or reduce the risk of an infection may be referred to as aprophylactic use to delay or prevent the onset of the symptoms of the infection and / or reducethe number or severity of symptoms of the infection. Suitably, administering the composition and / or combination and / or prebiotic of the invention to a subject may reduce the magnitude and / or amount of symptoms of an infection caused by the infectious agent or pathogen.Suitably, the present composition and / or combination and / or prebiotic may be administered toan infant, young child or child.Suitably, the present composition and / or combination and / or prebiotic may prevent and / orreduce the risk of an infection in a subject.Suitably, the present composition and / or combination and / or prebiotic may be administered toa subject and prevent and / or reduce the risk of an infection in the subject.Suitably, the composition and / or combination and / or prebiotic is not for use to reduce orprevent the presence of enteropathogens. Suitably, the composition and / or combinationand / or prebiotic is not for use to reduce or prevent the presence of enteropathogens in the gutof a subject.Suitably, the composition and / or combination and / or prebiotic may increase the levels of IL-6in the subject.IL-6 is secreted by macrophages in response to pathogen-associated molecular patterns (PAMPs). As such, IL-6 is an important component of fever and of the acute phase response. In addition, IL-6 is responsible for stimulating acute phase protein synthesis, as well as the production of neutrophils in the bone marrow. It supports the growth of B cells and isantagonistic to regulatory T cells. IL-6 has been shown to have an important role in preventingand / or controlling a number of infections including, for example, vaccinia virus and Listeriamonocytogenes (Kopf et al; 1994; Nature; 368; 339-342); herpes simplex virus (LeBlanc et al;1999; J Virol; 73(10)); influenza virus (Pyle et al.; 2017; PLoS Pathogens; 13(9), Dienz et al.; 2012; Mucosal Immunol; 5(3); 258-266, Gou et al; 2019; Front Immunol; 10:3102); enteric bacterial pathogens (Dann et al.; 2008; J Immunol; 180(10); 6816-6826); Escherichia coli(Dalrymple et al.; 1996; Infect Immun; 64(8): 3231-3235); Pulmonary Aspergillosis (Cenci etal.; 2001; J Infect Dis; 184(5); 610-617) and Candida albicans (van Enckevort et al.; 1999;Med Mycol; 37(6): 419-426). Suitably, the composition and / or combination and / or prebiotic may increase the levels of short-chain fatty acids (SFCA) in the subject.Suitably, the SCFA may be selected from acetate (Ethanoate, C1:0), butyrate (Butanonate,C4:0) and / or propionate (Propanoate, C3:0).SCFAs are produced when dietary fiber is fermented in the colon. SCFAs have diverse physiological roles in body functions; they can affect the production of lipids, energy and vitamins; affect appetite and cardiometabolic health; and have roles in lowering blood pressure in experimental models. SCFAs have been shown to have an important role in preventing and / or controlling a number of infections and immune responses (Kim et al.; Cell Host & Microbe; 2016; 20(2); 202-214).For example, SCFAs have been shown to have a protective affect against RSV (Antunes etal.; Nat Comm; 2019; 10; 3273); influenza virus (Trompette; Immunity; 2018; 48(5); 992-1005and Moriyama and Ichinobe; PNAS; 2018; 16(8); 3118-3125); viral bronchiolitis (Lynch et al.;J Exp Med; 2018; 215(2); 537-557) and general microbe infection (Schulthess et al.; Immunity; 2019; 50(2); 432-445). Notably, SCFA produced in the gut impacts systemic levels and local SFCA levels in other local organs, for example, the lungs. The cytokine and SCFA effects mediated by the present composition, combination and / or prebiotic may be systemic. As such, the cytokine effects (e.g. increase in the levels of IL-6and / or SCFAs) may systemically prevent or reduce the risk of an infection as described herein.The cytokine effects may occur locally in the gut, the lungs and / or the skin of the subject.Suitably, the SCFA effects may systemically prevent or reduce the risk of an infection asdescribed herein. The SCFA effects may occur locally in the gut, the lungs and / or the skin ofthe subject. Suitably, the cytokine or SCFA effects may occur in the gut of the subject. Suitably,the cytokine or SCFA effects may occur in the lungs of the subject. Accordingly, the cytokineor SCFA effects may prevent or reduce the risk of an infection in a particular organ or system. Suitably, the composition and / or combination and / or prebiotic may increase the levels ofindole-3-propionic acid in the subject. Indole-3-propionic acid has been shown to have animportant role in the immune response (Li et al., Front. Pharmacol., 2021, 12: 769501).Suitably, the composition and / or combination and / or prebiotic may modulate the permeabilityof the gut epithelial barrier of the subject. Suitably, the composition and / or combination and / orprebiotic may decrease the permeability of the gut epithelial barrier. Increased permeability ofthe gut epithelial barrier may be associated with an increase crossing of e.g. pathogens acrossthe intestinal epithelium. Accordingly, decreased permeability of the gut epithelial barrier maybe associated with a decreased crossing of e.g. pathogens across the intestinal epithelium. The composition and / or combination and / or prebiotic may reduce and / or prevent anexacerbation of symptoms of an infection. For example, the composition and / or combinationand / or prebiotic may reduce and / or prevent an exacerbation of symptoms caused byinflammation. The inflammation may be – for example – a pro-inflammatory response to anexisting infection. The existing infection may be the present infection or a separate infection caused by a different infectious agent or pathogen. For example, the present examples showthat a B. longum transitional microorganism reduced the level of increased permeability in amodel of gut epithelial barrier function following a pro-inflammatory insult. Without wishing tobe bound be theory, it is considered that the reduced gut epithelial barrier permeabilityfollowing an inflammatory insult may reduce the number / levels of pathogens that pass through the gut epithelial barrier during an inflammatory episode and thus prevent and / or reduce the risk of an infection; and / or prevent and / or reduce the risk of an exacerbation of symptoms of an existing infection. The combination or prebiotic for use in the present invention may be provided in the form of a composition. The composition of the invention may suitably be administered to an individual, for example an infant or a young child, in any suitable form such as a nutritional composition in a dosage unit (for example a tablet, a capsule, a sachet of powder, etc). The composition may be in powder, semi-liquid or liquid form. The composition may be added to a nutritional composition, an infant formula, a food composition, a supplement, a baby food, a follow-up formula, a growing-up milk, an infant cereal or a fortifier. In some embodiments, the composition of the present invention is an infant formula, a baby food, an infant cereal, a growing-up milk, asupplement or fortifier that may be intended for infants, young children or children.By way of example, the composition may comprise further components which may be beneficial in preventing and / or reducing the risk of an infection. In addition, or alternatively, the composition may comprise further components may be beneficial during the weaning period.For example, the composition may comprise a further probiotic – such as a probiotic withknown effects on preventing and / or reducing the risk of an infection - (e.g. B. lactis, L.rhamnosus, B. infantis), formula (e.g. partially hydrolysed formulae, extensively hydrolysedformulae, amino acid-based formulae, or intact formulae), baby food (with or without milk fat),milk fat, cereals, docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), butyrate and / orgamma-linolenic acid (GLA).Suitably, the further probiotic may be a B.infantis microorganism.The infection may be a viral, bacterial or fungal infection.Viral infectionViral respiratory infections, such as respiratory syncytial virus (RSV), affect nearly 90% of children by the age of two (Karpinnen et al, Clin Microbiol Infect, 2016;22;208.e1-e6). Such viral respiratory infections in infants and young children often lead to bronchiolitis, an inflammatory bronchial reaction in infants and young children (Pickles et al, J Pathol, 2015;235;266-276). Severe RSV-induced bronchiolitis is a major cause of morbidity and mortality in infants globally (Nair et al, Lancet, 2010;375;9725;2545-1555). The viral infection may be a viral gastrointestinal infection or a viral respiratory tract infection. The viral gastrointestinal infection may be a viral intestinal infection or a viral stomach infection. In a preferred embodiment, the viral infection is a viral respiratory tract infection. The viral respiratory tract infection may be a viral infection in the upper respiratory tract or in the lower respiratory tract. The disease associated with the viral infection will typically be common cold, influenza (flu), bronchitis, bronchiolitis, pneumonia, sore throat (pharyngitis), sinusitis, non-allergic rhinitis, severe acute respiratory syndrome (SARS), viral croup, otitis media, meningitis or diarrhoea. Typically, when the viral infection is in the respiratory tract, the disease associated with the respiratory tract infection is common cold, influenza (flu), bronchitis, bronchiolitis, pneumonia, sore throat (pharyngitis), sinusitis, non-allergic rhinitis, severe acute respiratory syndrome (SARS), viral croup or otitis media. Most often, the disease associated with the viral respiratory tract infection is common cold, influenza (flu), bronchitis, bronchiolitis or pneumonia. Accordingly, in a preferred embodiment of the invention the composition, combination and / orprebiotic of the invention is for use in treating and / or preventing a disease associated with aviral respiratory tract infection selected from the group consisting of common cold, influenza (flu), bronchitis, bronchiolitis and pneumonia. In a more preferred embodiment, the disease associated with the respiratory tract infection is selected from the group consisting ofbronchiolitis and pneumonia, in particular RSV-induced bronchiolitis and / or pneumonia, i.e.bronchiolitis and / or pneumonia caused by RSV. In an even more preferred embodiment, thedisease associated with the respiratory tract infection is bronchiolitis, in particular RSV- induced bronchiolitis. The symptoms most often associated with the viral infection, and which may be reduced by the composition of the invention, are irritation in the lungs, congestion in the lungs, excessive mucus production, fever, cough, wheezing, breathlessness, abdominal cramps, diarrhoea or vomiting. The above-mentioned infections may be caused by a variety of different viruses, including respiratory syncytial virus (RSV), parainfluenza virus (PIV), influenza virus such as influenza virus A (IVA) and / or influenza virus B (IVB), rhinovirus (RV), adenovirus (ADV), metapneumovirus (MPV), bocavirus (BoV), coronavirus (CoV), myxovirus, herpesvirus, enterovirus (EV), parachovirus (PeV) or a combination thereof. For example, the infection may be selected from an influenza virus, respiratory syncytial virus, rhinovirus, parainfluenza viruses, metapneumovirus, coronavirus, adenovirus, and bocavirus infection.Suitably the infection may be an influenza virus, respiratory syncytial virus or rhinovirusinfection. In a typical embodiment of the invention, the viral respiratory tract infection is causedby respiratory syncytial virus (RSV). Influenza virus is the infectious agent that causes influenza (flu). Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These symptoms begin from one to four days after exposure to the virus (typically two days) and last for about 2–8 days. Diarrhea and vomiting can occur, particularly inchildren. There are four types of influenza virus, termed influenza viruses A, B, C, and D.Aquatic birds are the primary source of Influenza A virus (IAV), which is also widespread invarious mammals, including humans and pigs. Influenza B virus (IBV) and Influenza C virus(ICV) primarily infect humans, and Influenza D virus (IDV) is found in cattle and pigs. IAV and IBV circulate in humans and cause seasonal epidemics, and ICV causes a mild infection, primarily in children. IDV can infect humans but is not known to cause illness. In humans, influenza viruses are primarily transmitted through respiratory droplets produced from coughing and sneezing. Transmission through aerosols and intermediate objects and surfaces contaminated by the virus also occur.Respiratory syncytial virus (RSV) a negative-sense, single-stranded RNA virus. It is the singlemost common cause of respiratory hospitalization in infants, with infection rates typicallyhigher during the cold winter months, causing bronchiolitis. RSV is spread throughcontaminated air droplets and can cause outbreaks both in the community and in hospital settings. Following initial infection via the eyes or nose, the virus will infect the epithelial cells of the upper and lower airway, causing inflammation, cell damage, and airway obstruction. Rhinovirus is the most common viral infectious agent in humans and is the predominant causeof the common cold. The three species of rhinovirus (A, B, and C) include around 160recognized types of human rhinovirus that differ according to their surface proteins(serotypes). They are lytic in nature and are among the smallest viruses, with diameters ofabout 30 nanometers. Symptoms of rhinovirus infection may include sore throat, runny nose,nasal congestion, sneezing and cough; sometimes accompanied by muscle aches, fatigue, malaise, headache, muscle weakness, or loss of appetite. Using a pneumonia Virus of Mice (PVM) model of human RSV infection, the present inventorshave surprisingly found that synbiotic interventions (namely, Bifidobacterium longumtransitional microorganism, Bifidobacterium longum subsp. infantis, Bifidobacterium lactis anda mix of HMOs as well as Bifidobacterium longum subsp. infantis in combination with a mix ofHMOs) in early life provides protection from virus-induced bronchiolitis. These findings support the use of the synbiotic in providing protection against and treatment of viral infections, in particular viral bronchiolitis, in early life and uncover functional benefits of the synbiotics to mount effective anti-viral immune responses associated with faster disease resolution.Thus, the composition, combination and / or prebiotic of the invention is, in particular, effectivefor use in the treatment and / or prevention of a viral infection in a subject.The composition, combination and / or prebiotic of the invention is particularly effective intreating, preventing, reducing the risk of contracting and / or reducing the symptoms of a viral infection caused by RSV. Thus, composition of the invention is particularly preferred for usein treating, preventing, reducing the risk of contracting and / or reducing the symptoms of RSV-induced bronchiolitis or RSV-induced pneumonia.The composition, combination and / or prebiotic of the invention is useful for treating and / or preventing viral infections, in particular respiratory tract infection in a human of any age. Thus, the human to be treated with the composition of the invention may be selected from the group consisting of 0 to <1 year (infants), 1 to <3 years (young children) and 3 to <6 years (children), including 3 to <5 years (pre-schoolers). Sustained immune benefit Viral infections can also interfere with the normal functioning of the host and may lead to more severe infection-related disorders, including immunopathology following respiratory viral infection (Newton et al, Semin Immunopathol, 2016;38;471-482), such as long-termalterations in the immune system (e.g. inflammatory responses) and subsequent allergic orinflammatory diseases later in life. For example, uncontrolled inflammatory responsesfollowing viral infection of the respiratory tract can lead to pathological airway smooth muscle remodelling, a hallmark feature of asthma reported to commence in early life (O’Reilly et al, JACI, 2013;131;1024-1032) as well as playing a central role in the pathogenesis of chronicobstructive pulmonary disease (COPD; Yan F et al, J Transl Med, 2018;16;262-270). Thus,severe viral airway infections in early life represent a major independent risk factor forsubsequent development of respiratory diseases such as allergic airway disease (e.g. asthma;Feldman et al, Am J Respir Crit Care Med, 2015;191;34-44) and chronic obstructive pulmonary disease (Savran O et al. Int J Chron Obstruct Pulmon Dis.2018; 13: 683–693) in later life.Thus, the composition and / or combination of the invention is, in particular, effective for use inpromoting a sustained immune benefit in a subject.Accordingly, in a further aspect, the invention provides a composition according to theinvention for use in promoting a long-term immune benefit in a subject.In a further aspect, the invention provides the use of a composition according to the inventionfor the manufacture of a medicament for promoting a long-term immune benefit in a subject.In a further aspect, the invention provides a method of promoting a long-term immune benefitin a subject, the method comprising administering to the subject a composition according to the invention.In a further aspect, the invention provides a combination according to the invention for use inpromoting a long-term immune benefit in a subject. In a further aspect, the invention provides the use of a combination according to the inventionfor the manufacture of a medicament for promoting a long-term immune benefit in a subject.In a further aspect, the invention provides a method of promoting a long-term immune benefitin a subject, the method comprising administering to the subject a combination according tothe invention.Promoting a long-term immune benefit comprises:i. promoting long-term respiratory health;ii. preventing and / or reducing the risk of allergen sensitisation; and / oriii. preventing and / or reducing the risk of developing a respiratory conditionlater in life. Suitably, promoting a long-term immune benefit refers to promoting long-term respiratory health. Suitably, promoting a long-term immune benefit refers to preventing and / or reducing the risk of allergen sensitisation. Suitably, promoting a long-term immune benefit refers to preventing and / or reducing the risk of developing a respiratory condition later in life. As used herein, the phrase “long-term” encompasses the effect after the termination of the intervention or treatment. The effect “long-tem” can be from 1 week to several years, forexample from 2 to 4 weeks, from 2 to 6 weeks, from 2 to 8 weeks, from 1 to 6 months, from 2to 12 months, from 12 months to 12 years, such as from 2 years to 10 years, or from 4 yearsto 5 years, after the termination of the intervention or treatment. Hence, the effect “long term”may be present when the subject has reached an age of 3 years or more, preferably from 3 to12 years, more preferably from 3 to 10 years, even more preferably from 3 to 8, mostpreferably from 3 to 6 years, in particular from 3 to 5 years or from 3 to 4 years. Suitably, the long-term benefit lasts until the subject is at least 5 years of age, such as at least 10 years of age, at least 20 years of age or at least 30 years of age. Suitably, the composition and / or combination of the invention may prevent a complication associated with a viral infection of the respiratory tract. Suitably, this effect may be the long- term prevention of a complication associated with a viral infection of the respiratory tract. Such complications may be those associated with the immune systems, such as the inflammatoryresponse, and include immunopathology following respiratory viral infection, such as long-term alterations in the immune system (e.g. long-term alterations in inflammatory responses) and pathological airway smooth muscle remodelling. These complications may in turn predispose the subject to subsequent allergic or inflammatory diseases later in life, such asallergic respiratory diseases or chronic inflammatory diseases of the respiratory tract.Allergic sensitization and respiratory conditions Given that viral respiratory tract infections in early life represent a major independent risk factor for subsequent asthma, recurrent wheeze and chronic obstructive pulmonary disease later in life (Savran et al, Int J Chron Obstruct, 2015;191;34-44; and Feldman et al.2015 Am J RespirCrit Care Med, 191;34-44), the composition and / or combination of the invention is alsoeffective use in preventing and / or reducing the risk of developing respiratory conditions, suchas chronic inflammatory diseases of the respiratory tract and allergic airway diseases. Since viral infections, in particular infection with RSV, is associated with subsequent development of allergic airway diseases, such as asthma later in life (Feldman et al.2015 Am J Respir Crit Care Med, 191;34-44), the composition and / or combination of the invention is also effective for use in preventing and / or reducing the risk of allergen sensitisation and / or developing an allergic respiratory tract disease in a subject.Accordingly, in a further aspect the invention provides a composition according to the inventionfor use in i) preventing and / or reducing the risk of allergen sensitisation and / or ii) preventing and / or reducing the risk of developing a respiratory condition in a subject.In a further aspect, the invention provides a composition according to the invention for use inpreventing and / or reducing the risk of developing asthma in a subject. In a further aspect, the invention provides the use of a composition according to the invention for the manufacture of a medicament for i) preventing and / or reducing the risk of allergen sensitisation and / or ii) preventing and / or reducing the risk of developing a respiratory condition in a subject. In a further aspect, the invention provides the use of a composition according to the invention for the manufacture of a medicament for preventing and / or reducing the risk of developing asthma in a subject.In a further aspect, the invention provides a method of i) preventing and / or reducing the riskof allergen sensitisation and / or ii) preventing and / or reducing the risk of developing a respiratory condition in a subject, the method comprising administering to the subject a composition according to the invention.In a further aspect, the invention provides a method of preventing and / or reducing the risk ofdeveloping asthma in a subject, the method comprising administering to the subject a composition according to the invention.Accordingly, in a further aspect the invention provides a combination according to the inventionfor use in i) preventing and / or reducing the risk of allergen sensitisation and / or ii) preventing and / or reducing the risk of developing a respiratory condition in a subject.In a further aspect, the invention provides a combination according to the invention for use inpreventing and / or reducing the risk of developing asthma in a subject. In a further aspect, the invention provides the use of a combination according to the invention for the manufacture of a medicament for i) preventing and / or reducing the risk of allergen sensitisation and / or ii) preventing and / or reducing the risk of developing a respiratory condition in a subject. In a further aspect, the invention provides the use of a combination according to the invention for the manufacture of a medicament for preventing and / or reducing the risk of developing asthma in a subject.In a further aspect, the invention provides a method of i) preventing and / or reducing the riskof allergen sensitisation and / or ii) preventing and / or reducing the risk of developing a respiratory condition in a subject, the method comprising administering to the subject acombination according to the invention.In a further aspect, the invention provides a method of preventing and / or reducing the risk ofdeveloping asthma in a subject, the method comprising administering to the subject acombination according to the invention.Respiratory conditions include chronic inflammatory diseases of the respiratory tract andallergic respiratory diseases.Chronic inflammatory diseases of the respiratory tract include chronic obstructive pulmonarydisease (COPD) and asthma, including allergic asthma and non-allergic asthma.COPD is the term for a collection of lung diseases including chronic bronchitis, emphysemaand chronic obstructive airways disease. People with COPD have difficulties breathing, primarily due to the narrowing of their airways. Asthma is a chronic respiratory condition marked by inflammation and bronchospasm, causingdifficulty in breathing. It is usually associated with an allergic reaction or other forms ofhypersensitivity. Inflammation and narrowing of the small airways in the lungs cause asthmasymptoms, which can be any combination of cough, wheeze, shortness of breath and chesttightness. Asthma often develops during childhood, particularly at the preschool stage (3 yearsto 5 years old). Allergic respiratory tract diseases include recurrent wheeze and asthma, including allergic asthma.For i) preventing and / or reducing the risk of allergen sensitisation and / or ii) preventing and / orreducing the risk of developing a respiratory condition in a subject, the composition of the invention is preferably administered to a human having an age from 0 to <3 years, preferably from 0 to 2 years, more preferably from 0 to <1 year, such as from 0 to 6 months. This, in turn,prevents and / or reduces the risk of developing a respiratory condition when the subject hasreached an age of 3 years or more, preferably from 3 to 12 years, more preferably from 3 to 10 years, even more preferably from 3 to 8, most preferably from 3 to 6 years, in particular from 3 to 5 years or from 3 to 4 years.Since viral infections, in particular infection with RSV, is often associated with bacterial co-infection (Thorburn et al, Thorax, 2006;61(7);611-615) or secondary infection (Sande et al,Nature Communications, 2019;10;2218), including antibiotic use, the composition and / orcombination of the invention is also effective for use in preventing or reducing the risk of abacterial co-infection and / or a bacterial secondary infection associated with respiratory viral infection in a mammal, in particular a human. Pathogenic bacteria typically involved in co- infections or secondary infections include Staphylococcus aureus, Streptococcus pneumoniae and / or Haemophilus influenza. PrebioticThe invention further provides a prebiotic for use in preventing, reducing the risk of and / ortreating an infection in a subject by promoting the growth of a Bifidobacterium longumtransitional microorganism in the gut of the subject, wherein the prebiotic is a HMO mixture consisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'- sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), and wherein the Bifidobacteriumlongum transitional microorganism has an Average Nucleotide Identity (ANI) of at least 98%with CNCM I-5942 and / or has at least one identifying characteristic of the B. longumtransitional strain deposited under deposit number CNCM I-5942.In a further aspect, the invention provides the use of a prebiotic for the manufacture of amedicament for preventing, reducing the risk of and / or treating an infection in a subject bypromoting the growth of a Bifidobacterium longum transitional microorganism in the gut of theinfant or young child, wherein the prebiotic is a HMO mixture consisting of 2'-fucosyllactose(2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'- sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL)and / or lacto-N-neotetraose (LNnT), and wherein the Bifidobacterium longum transitionalmicroorganism has an Average Nucleotide Identity (ANI) of at least 98% with CNCM I-5942and / or has at least one identifying characteristic of the B. longum transitional strain depositedunder deposit number CNCM I-5942.In a further aspect, the invention provides a method of preventing, reducing the risk of and / ortreating an infection in a subject by promoting the growth of a Bifidobacterium longumtransitional microorganism in the gut of the subject, wherein the method comprisesadministering a prebiotic to the infant or young child, wherein the prebiotic is a HMO mixtureconsisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'- sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), and wherein the Bifidobacteriumlongum transitional microorganism has an Average Nucleotide Identity (ANI) of at least 98%with CNCM I-5942 and / or has at least one identifying characteristic of the B. longumtransitional strain deposited under deposit number CNCM I-5942.The HMO mixture may be as defined herein.Preferably, the prebiotic is for use in preventing and / or reducing the risk of an infection in a subject. Preferably, the subject is an infant or a young child. In some embodiments, the composition and / or combination of the invention may furthercomprise a prebiotic (i.e. in addition to the HMO mixture as described herein). Suitably, theprebiotic is a glycan substrate. Glycan Substrate / Carbohydrate-Active Enzymes (CAZymes)The B. longum transitional microorganisms encode a profile of Carbohydrate-Active Enzymes(CAZymes). Without wishing to be bound by theory, it is considered that targeting these CAZymes by, for example, providing the HMO mixture as described herein and / or suitable glycan substrates in the form of a prebiotic, may promote the growth and / or survival of theBifidobacterium longum transitional microorganisms in the gut microbiota of an infant or youngchild.Suitably, promoting the growth and / or survival of the B longum transitional microorganism mayrefer to increasing the number and / or concentration of the B longum transitionalmicroorganism in the gut microbiota.In particular, the CAZymes encoded by the Bifidobacterium longum transitional strain NCC5025, which wase deposited with the Institute Pasteur according to Budapest Treaty on29thofMarch 2023 receiving the deposit number CNCM I-5942; have been determined, as describedherein above.Suitably, the prebiotic for use in the present invention may comprise a glycan substrate that iscapable of being degraded by a CAzyme as described herein. Suitably, the prebiotic for use in the present invention may comprise a combination of glycansubstrates that is capable of being degraded by a CAZyme as described herein. Suitableglycan substrates are known in the art. The combination of glycan substrates may comprise at least 2, at least 4, at least 10, at least 20, at least 30, at least 40 or at least 50 glycan substrates.The prebiotic may comprise at least 2, at least 4, at least 10, at least 20, or at least 30 glycansubstrates. Suitably, the glycan substrate may be a complex carbohydrate like arabinan, arabinogalactan, and arabinoxylan. Suitably, the glycan substrate may comprise or consist of pectin, arabinogalactan and / or starch. Suitably, the glycan substrate may comprise or consist of pectin. Suitably, the glycan substrate may comprise or consist of arabinogalactan. Suitably, the glycan substrate may comprise or consist of starch. As described herein, the present B. longum transitional microorganism grows well on a set of food derived fibres (e.g. inulin and arabinan). Suitably, the glycan substrate may comprise or consist of inluin. Suitably, the glycan substrate may comprise or consist of arabinan.Suitably, the glycan substrate may comprise or consist of inulin and arabinan.Suitably, the glycan substrate is provided in the form of a dietary fiber. For example, the dietary fiber may be a prebiotic fiber. Suitably, the glycan substrate may be comprised in an ingredient, for example a dietary ingredient. The ingredient containing one or several glycan substrates may be selected from the group consisting of purified polysaccharide or purified oligosaccharide, a dietary fiber ingredient, a semi-purified food ingredient, a raw food ingredient, a food additive, a HMO, a semi-purified or purified peptido-glycan. The semi-purified food ingredient may be a fruit, vegetable or cereal extract.The raw food ingredient may be a fruit, vegetable, cereal, algae or microalgae.The food additive may be a guar gum or gum arabic. Suitably, the peptide-glycan may be a GAG. Suitably, the glycan substrate may be comprised in a purified fiber. The pectin may be comprised in fruit or vegetable pectin. Accordingly, suitable ingredients comprising pectin include, but are not limited to, fruits (e.g., apple, pear), vegetables, legumes (peas), and roots (e.g., sugar beet). Suitable purified fibers comprising arabinogalactan include peach pectin. Suitably, the pectin extracted from sugar beet contains arabinan, galactans and arabinogalactans and may be provided as an ingredient. The arabinogalactan may be comprised in fruit or vegetable pectin. Illustrative suitable ingredients comprising arabinogalactan include, but are not limited to, fruits, vegetables, whole grain cereals and sea weed dietary fiber. Suitable purified fibers comprising arabinogalactan include peach pectin, larch wood arabinogalactan, and Arabic gum. Suitably, the arabinogalactan may be provided in larch wood arabinogalactan. The starch may be comprised in resistant-starch from cereals (whole grains), legumes, vegetables (e.g., corn) and roots (e.g., potato). Illustrative suitable ingredients comprising starch include, but are not limited to, corn. Suitable purified fibers comprising starch include high amylose starch and resistant dextrin. Suitably, the starch may be provided in a potato, corn or other ingredient. Suitably, the starch may be comprised in a potato ingredient.Human milk oligosaccharide (HMO)Suitably, the prebiotic comprises one or more additional HMO(s). Suitably, the additionalHMO(s) is / are different to those provided in the HMO mixture as described herein.Suitably, the additional HMO(s) is / are capable of being metabolized by the B longumtransitional microorganism. Suitably, the additional HMO(s) may be capable of promotinggrowth and / or survival of the B. longum transitional strain. HMOs capable of promoting growthand / or survival of the B. longum transitional strain may be determined by e.g. anaerobic cultureof the B. longum transitional strain with the HMO to be tested. Growth and / or survival of theB. longum transitional strain may be determined by measuring bacteria cell number, celldensity (e.g. measured by optical density) and / or the abundance of 16S rDNA – for exampleusing PCR methods. An illustrative assay for measuring growth of a B. longum transitional strain in the presence of HMOs is provided in present Example 6. An HMO capable ofpromoting growth and / or survival of the B. longum transitional strain may increase the numberof B. longum transitional bacteria in an anaerobic culture by at least 20%, at least 30%, atleast 40%, at least 50%, at least 75% or at least 100% compared to the number of B. longum transitional bacteria in a control anaerobic culture which does not comprise the HMO. Suitably, a HMO capable of promoting growth and / or survival of the B. longum transitional strain may increase the number of B. longum transitional bacteria in an anaerobic culture by a statistically signifiicant amount (e.g. p-value <0.05 as determined by one-way ANOVA) compared to the number of B. longum transitional bacteria in a control anaerobic culture which does not comprise the HMO. The HMO may be a fucosylated oligosaccharide (i.e. an oligosaccharide having a fucose residue; e.g. 3-fucosyllactose (3-FL), difucosyllactose (DiFL), lacto-N-fucopentaose (e.g. lacto-N-fucopentaose II, lacto-N-fucopentaose III, lacto-N-fucopentaose V), lacto-N- fucohexaose, lacto-N-difucohexaose I, fucosyllacto-N-hexaose, fucosyllacto-N-neohexaose, difucosyllacto-N-hexaose I, difucosyllacto-N-neohexaose II and any combination thereof), an N-acetylated oligosaccharide (e.g. para-lacto-N-neohexaose (para-LNnH), LNnT (lacto-N-neotetraose), DSLNT (disialyllacto-N-tetraose), lacto-N-hexaose, lacto-N-neohexaose, para-lacto-N-hexaose, para-lacto-N-neohexaose, lacto-N-octaose, lacto-N- neooctaose, iso- lacto-N-octaose, para- lacto-N-octaose and lacto-N-decaose and any combinations thereof) and / ora sialylated oligosaccharide (e.g. Lst (sialyllacto-N-tetraose), Lst-a, Lst-b or Lst-c)).Subject In one embodiment, the subject is an infant. In one embodiment, the subject is a young child. In one embodiment, the subject is a child.The composition or combination according to the invention is for use in infants, young childrenor children. It is particularly adapted for infants under 6 months of age. In general, formula-fed infants have an underdeveloped immune system compared with adults and are more prone to viral infections than breastfed, and the younger the infant is, the less developed the immune system. Accordingly, the composition or combination is particularly useful for preterm infants and / or low or very low birth weight infants, since these infants are even more vulnerable and prone to viral infections. In another particularly interesting embodiment, the composition or combination is used in infants delivered via Caesarean section. Caesarean section born infants are born in a hospital in an environment having more pathogens against which the antibodies, transferred from the mother to the infant, are not effective against. Further, antibiotic administration is a recommended medical practice for C- section birth in order to prevent infection. Such interventions are potent disruptors of microbial communities (the mother’s or the child’s) and antibiotic treatment in early life is associated with an increased risk of developing immune mediated disorders later in life. Caesarean section born infants have a delayed and less optimal colonization of the large intestinal tract and are therefore also more prone to infections.The infants, young children or children may be born term or preterm. In a particularembodiment, the composition or combination of the invention is for use in infants, youngchildren or children that were born preterm. Preterm infants may be at increased risk of poornutrient utilization, impaired lean body mass growth, fat accumulation in the visceral area and metabolic disease later in life.In one embodiment, the subject is an infant, a young child or a child that was born small forgestational age or low birth weight.Infants, young children or children with low birth weight may or may not be preterm, andsimilarly, infants, young children or children who are small for gestational age may or may notbe preterm.The composition or combination of the present invention may also be used in an infant, ayoung child or a child that was born by C-section or that was vaginally delivered.All infants, young children and children can benefit from the invention as all of them are or canbe, at a certain age, susceptible to acquiring an unbalanced intestinal / gut microbiota. In some advantageous embodiments of the invention, the composition or combination in foruse infants, young children or children having a fragile or unbalanced microbiota or dysbiosisof microbiota, such as preterm infants, infants born by Caesarean-section, infants born small for gestational age or with low birth weight, hospitalized infants / young children / children,infants / young children / children treated or having been treated by antibiotics and / orinfants / young children / children suffering or having suffered from gut infection and / or gutinflammation. It is indeed foreseen that the composition or combination of the invention may be even more beneficial to infants born with possibly impaired gut microbiota or fragile infants / youngchildren / children (such as prematurely born infants and / or infants born by C-section). It is alsoforeseen that the composition or combination of the invention may be even more beneficial toinfants / young children / children exhibiting intestinal disorders (such as diarrhea, infections orcolic), especially after birth, for example, during the first 4 weeks after birth. In embodiments of the invention, the infants born prematurely or born by caesarean section or born small for gestational age or with low birth weight, or exhibiting unbalanced or abnormalgut microbiota or suffering or having suffered from gut infection and / or gut inflammation, aretargeted by the composition or combination of the present invention, and especially when the infants are 0-6 months of age. Without being bound by the theory, it is believed that youngerinfants benefit even more from the composition or combination of the invention, especiallywhen the infants have (or are at risk of having) an unbalanced intestinal microbiota and / or have a fragile health condition (as exemplified by the conditions cited above).The composition (e.g. nutritional composition) or combination can be administered (or givenor fed) at an age and for a period that depends on the needs. In one embodiment, the infants or young children are 0-36 months of age, such as 0-12 months or 0-6 months of age. It is foreseen that the composition or combination of the invention may be even more beneficial to infants just after birth (0-4 weeks or 0-8 weeks) as their intestinal tract may be more fragile.In some embodiments the composition (e.g. nutritional composition) or combination accordingto the invention can be for use before and / or during the weaning period.In some embodiments the composition (e.g. nutritional composition) or combination accordingto the invention is for use in a subject at risk and / or in need. The subject at risk and / or in need may be bottle-fed and / or formula-fed. In one embodiment the composition or combination of the invention is given to the subject as a supplementary composition to the mother's milk. In some embodiments the subject receives the mother's milk during at least the first 2 weeks, first 1, 2, 4, or 6 months. In one embodimentthe composition (e.g. nutritional composition) or combination of the invention is given to thesubject after such period of mother's nutrition, or is given together with such period of mother's milk nutrition. In another embodiment the composition or combination is given to the subject as the sole or primary nutritional composition during at least one period of time, e.g. after the 1st, 2ndor 4thmonth of life, during at least 1, 2, 4 or 6 months. In one embodiment the nutritional composition of the invention is a complete nutritional composition (fulfilling all or most of the nutritional needs of the subject). In another embodiment the nutrition composition of the invention is a supplement or a fortifier intended for example to supplement human milk or tosupplement an infant formula or a follow- on formula.Nutritional compositionIn some embodiments, the composition of the invention is in the form of a nutritionalcomposition. The nutritional composition according to the invention can be for example an infant formula, a starter infant formula, a follow-on or follow-up formula, a growing-up milk, a baby food, an infant cereal composition, a fortifier such as a human milk fortifier, or a supplement. In some particular embodiments, the composition of the invention is an infant formula, a fortifier or a supplement that may be intended for the first 4 or 6 months of age. In a preferred embodimentthe nutritional composition of the invention is an infant formula.In some other embodiments, the nutritional composition of the present invention is a fortifier. The fortifier can be a breast milk fortifier (e.g. a human milk fortifier) or a formula fortifier such as an infant formula fortifier or a follow-on / follow-up formula fortifier. When the nutritional composition is a supplement, it can be provided in the form of unit doses. In such cases it is particularly useful to define the amount of oligosaccharides and probiotics in terms of daily dose to be administered to the infant or young child.When the nutritional composition is a supplement, it may comprise the HMO mixture asdescribed herein and the Bifidobacterium longum subsp microorganism, and no otheradditional nutrient on top of the excipients necessary to obtain a stable nutritional composition. The nutritional composition of the present invention can be in solid (e.g. powder), liquid or gelatinous form. In a specific embodiment the nutritional composition is a supplement, wherein the supplement is in powder form and provided in a sachet, preferably a sachet with 0.1 to 20 g per sachet, for example 1 to 10 g per sachet, or in the form of a syrup, preferably a syrup with a total solid concentration of 5 to 75 g / 100 mL (5 to 75% (w / v)). When the supplement is in powder form, it may comprise a carrier. It is however preferred that the supplement is devoid of a carrier. When the supplement is in the form of a syrup, the components are preferably dissolved or suspended in water acidified with citrate. In a particular embodiment the nutritional composition according to the invention is a hypoallergenic composition. In another particular embodiment the composition according to the invention is a hypoallergenic nutritional composition. Other ingredients The composition or combination according to the present invention may also comprise other types of oligosaccharide(s), polysaccharides and / or a fiber(s) and / or a precursor(s) thereof. The other oligosaccharide and / or fiber and / or precursor thereof may be selected from the list comprising human milk oligosaccharides (HMOs), galacto-oligosaccharides (GOS), fructo- oligosaccharides (FOS), xylooligosaccharides (XOS), cello-oligosaccharides (COS), arabinoxylans, arabinans, xylans, inulin, polydextrose, beta-glucans, pectins and any combination thereof and any derived preparations thereof (e.g. partial hydrolysis). They may be in an amount between 0 and 10% by weight of composition. In a particular embodiment, the nutritional composition can also contain at least one BMO (bovine milk derived oligosaccharide). Additional HMOs which may be included in the nutritional composition according to the presentinvention may be selected from the group consisting of lacto-N- fucopentaose (e.g. lacto-N-fucopentaose II, lacto-N-fucopentaose III, lacto-N-fucopentaose V), lacto-N-fucohexaose, lacto-N-difucohexaose I, fucosyllacto-N-hexaose, fucosyllacto-N-neohexaose, difucosyllacto- N-hexaose I, difucosyllacto-N-neohexaose II, para-lacto-N-neohexaose (para-LNnH), lacto-N-hexaose, lacto- N-neohexaose, para-lacto-N-hexaose, para-lacto-N-neohexaose, lacto-N-octaose, lacto-N-neooctaose, iso-lacto-N-octaose, para- lacto-N-octaose, lacto-N-decaose,and any combination thereof.In some embodiments, the composition or combination according to the invention comprises at least one additional HMO. In other embodiments, the composition or combination according to the present invention is devoid of any further HMOs. Thus, the HMO mixture as described herein may be the only HMOs in the composition or combination of the invention.The composition or combination of the present invention can further comprise at least onefurther probiotic (or probiotic strain), such as at least one further probiotic bacterial strain. The probiotic microorganisms most commonly used are principally bacteria and yeasts of thefollowing genera: Lactobacillus spp., Lacticaseibacillus spp, Limosilactobacillus spp,Streptococcus spp., Enterococcus spp., Bifidobacterium spp. and Saccharomyces spp.In some particular embodiments, the probiotic is a probiotic bacterial strain. In some specificembodiments, it is particularly Bifidobacteria and / or Lactobacilli.Suitable probiotic bacterial strains include Lactobacillus rhamnosus ATCC 53103 availablefrom Valio Oy of Finland under the trademark LGG, Lactobacillus rhamnosus CGMCC 1.3724,Lactobacillus paracasei CNCM I-2116, Lactobacillus johnsonii CNCM I-1225, Streptococcussalivarius DSM 13084 sold by BLIS Technologies Limited of New Zealand under thedesignation KI2, B. longum CNCM I-2618 (B. longum NCC2705), Bifidobacterium breve soldby Danisco under the trademark Bb-03, Bifidobacterium breve sold by Morinaga under thetrade mark M-16V, Bifidobacterium infantis sold for example by Procter & GambIe Co. underthe trademark Bifantis, and Bifidobacterium breve sold by Institut Rosell (Lallemand) underthe trademark R0070. The composition or combination according to the invention may contain from 10e3 to 10e12 cfu of the at least one (further) probiotic strain, more preferably between 10e7 and 10e12 cfu such as between 10e8 and 10e10 cfu of probiotic strain per g of composition or combination on a dry weight basis. In one embodiment, the probiotics are viable. In another embodiment, the probiotics are non- replicating or inactivated. There may be both viable probiotics and inactivated probiotics in some other embodiments. Probiotic components and metabolites can also be added. The nutritional composition according to the invention generally contains a protein source. The protein can be in an amount of from 1.6 to 3 g per 100 kcal. In some embodiments, especiallywhen the composition is intended for premature infants, the protein amount can be between2.4 and 4 g / 100kcal or more than 3.6 g / 100kcal. In some other embodiments the protein amount can be below 2.0 g per 100 kcal, e.g. between 1.8 to 2 g / 100 kcal, or in an amount below 1.8 g per 100 kcal. Protein sources based on whey, casein and mixtures thereof may be used as well as protein sources based on soy. As far as whey proteins are concerned, the protein source may be based on acid whey or sweet whey or mixtures thereof and may include alpha-lactalbumin and beta-lactoglobulin in any desired proportions. In some advantageous embodiments the protein source is whey predominant (i.e. more than 50% of proteins are coming from whey proteins, such as 60% or 70%). The proteins may be intact or hydrolysed or a mixture of intact and hydrolysed proteins. By the term “intact” is meant that the main part of the proteins are intact, i.e. the molecular structure is not altered, for example at least 80% of the proteins are not altered, such as at least 85% of the proteins are not altered, preferably at least 90% of the proteins are not altered, even more preferably at least 95% of the proteins are not altered, such as at least 98% of the proteins are not altered. In a particular embodiment, 100% of the proteins are not altered. The term “hydrolysed” means in the context of the present invention a protein which has been hydrolysed or broken down into its component amino acids. The proteins may be either fully or partially hydrolysed. It may be desirable to supply partially hydrolysed proteins (degree of hydrolysis between 2 and 20%), for example for infants or young children believed to be at risk of developing cow’s milk allergy. If hydrolysed proteins are required, the hydrolysis process may be carried out as desired and as is known in the art. For example, whey protein hydrolysates may be prepared by enzymatically hydrolysing the whey fraction in one or more steps. If the whey fraction used as the starting material is substantially lactose free, it is found that the protein suffers much less lysine blockage during the hydrolysis process. This enables the extent of lysine blockage to be reduced from about 15% by weight of total lysine to less than about 10% by weight of lysine; for example about 7% by weight of lysine which greatly improves the nutritional quality of the protein source. In an embodiment of the invention at least 70% of the proteins are hydrolysed, preferably at least 80% of the proteins are hydrolysed, such as at least 85% of the proteins are hydrolysed, even more preferably at least 90% of the proteins are hydrolysed, such as at least 95% of the proteins are hydrolysed, particularly at least 98% of the proteins are hydrolysed. In a particular embodiment, 100% of the proteins are hydrolysed. In one particular embodiment the proteins of the nutritional composition are hydrolyzed, fully hydrolyzed or partially hydrolyzed. The degree of hydrolysis (DH) of the protein can be between 8 and 40, or between 20 and 60 or between 20 and 80 or more than 10, 20, 40, 60, 80 or 90. The protein component can alternatively be replaced by a mixture or synthetic amino acid, for example for preterm or low birth weight infants.In a particular embodiment, the nutritional composition or the growing-up milk according to theinvention is a hypoallergenic composition. In another particular embodiment, the compositionaccording to the invention is a hypoallergenic nutritional composition or growing-up milk. The nutritional composition according to the present invention generally contains a carbohydrate source. This is particularly preferable in the case where the nutritional composition of the invention is an infant formula. In this case, any carbohydrate source conventionally found in infant formulae such as lactose, sucrose, saccharose, maltodextrin, starch and mixtures thereof may be used although one of the preferred sources of carbohydrates is lactose. The nutritional composition according to the present invention generally contains a source of lipids. This is particularly relevant if the nutritional composition of the invention is an infantformula. In this case, the lipid source may be any lipid or fat which is suitable for use in infantformulae. Some suitable fat sources include palm oil, structured triglyceride oil, high oleic sunflower oil and high oleic safflower oil, medium-chain-triglyceride oil. The essential fatty acids linoleic and α-linolenic acid may also be added, as well small amounts of oils containinghigh quantities of preformed arachidonic acid and docosahexaenoic acid such as fish oils ormicrobial oils. The fat source may have a ratio of n-6 to n-3 fatty acids of about 5:1 to about 15:1; for example about 8:1 to about 10:1. The nutritional composition of the invention may also contain all vitamins and minerals understood to be essential in the daily diet and in nutritionally significant amounts. Minimum requirements have been established for certain vitamins and minerals. Examples of minerals, vitamins and other nutrients optionally present in the composition of the invention include vitamin A, vitamin B1, vitamin B2, vitamin B6, vitamin B12, vitamin E, vitamin K, vitamin C, vitamin D, folic acid, inositol, niacin, biotin, pantothenic acid, choline, calcium, phosphorous, iodine, iron, magnesium, copper, zinc, manganese, chlorine, potassium, sodium, selenium, chromium, molybdenum, taurine, and L-carnitine. Minerals are usually added in salt form. The presence and amounts of specific minerals and other vitamins will vary depending on the intended population. If necessary, the nutritional composition of the invention may contain emulsifiers andstabilisers such as soy, lecithin, citric acid esters of mono- and di-glycerides, and the like.The nutritional composition of the invention may also contain other substances which may have a beneficial effect such as lactoferrin, nucleotides, nucleosides, and the like. The nutritional composition of the invention may also contain carotenoid(s). In some particular embodiments of the invention, the nutritional composition of the invention does not comprise any carotenoid. Manufacture of a nutritional composition The nutritional composition according to the invention may be prepared in any suitable manner. A composition will now be described by way of example. For example, a formula such as an infant formula may be prepared by blending together the protein source, the carbohydrate source and the fat source in appropriate proportions. If used, the emulsifiers may be included at this point. The vitamins and minerals may be added at this point but they are usually added later to avoid thermal degradation. Any lipophilic vitamins, emulsifiers and the like may be dissolved into the fat source prior to blending. Water, preferably water which has been subjected to reverse osmosis, may then be mixed in to form a liquid mixture. The temperature of the water is conveniently in the range between about 50°C and about 80°C to aid dispersal of the ingredients. Commercially available liquefiers may be used to form the liquid mixture. The oligosaccharide(s) may be added at this stage, especially if the final product is to have a liquid form. If the final product is to be a powder, they may likewise be added at this stage if desired. The liquid mixture is then homogenised, for example in two stages. The liquid mixture may then be thermally treated to reduce bacterial loads, by rapidly heating the liquid mixture to a temperature in the range between about 80°C and about 150°C for a duration between about 5 seconds and about 5 minutes, for example. This may be carried out by means of steam injection, an autoclave or a heat exchanger, for example a plate heat exchanger. Then, the liquid mixture may be cooled to between about 60°C and about 85°C for example by flash cooling. The liquid mixture may then be again homogenised, for example in two stages between about 10 MPa and about 30 MPa in the first stage and between about 2 MPa andabout 10 MPa in the second stage. The homogenised mixture may then be further cooled toadd any heat sensitive components, such as vitamins and mineraIs. The pH and solids content of the homogenised mixture are conveniently adjusted at this point. If the final product is to be a powder, the homogenised mixture is transferred to a suitable drying apparatus such as a spray dryer or freeze dryer and converted to powder. The powder should have a moisture content of less than about 5% by weight. The oligosaccharide(s) may also or alternatively be added at this stage by dry-mixing or by blending them in a syrup form of crystals, along with the probiotic strain(s), and the mixture is spray-dried or freeze-dried. If a liquid composition is preferred, the homogenised mixture may be sterilised then aseptically filled into suitable containers or may be first filled into the containers and then retorted. In another embodiment, the composition of the invention may be a supplement. The supplement may be in the form of tablets, capsules, pastilles or a liquid for example. The supplement may further contain protective hydrocolloids (such as gums, proteins, modified starches), binders, film forming agents, encapsulating agents / materials, wall / shell materials, matrix compounds, coatings, emulsifiers, surface active agents, solubilizing agents (oils, fats, waxes, lecithins etc.), adsorbents, carriers, fillers, co-compounds, dispersing agents, wetting agents, processing aids (solvents), flowing agents, taste masking agents, weighting agents, jellifying agents and gel forming agents. The supplement may also contain conventional pharmaceutical additives and adjuvants, excipients and diluents, including, but not limited to, water, gelatine of any origin, vegetable gums, lignin-sulfonate, talc, sugars, starch, gum arabic, vegetable oils, polyalkylene glycols, flavouring agents, preservatives, stabilizers, emulsifying agents, buffers, lubricants, colorants, wetting agents, fillers, and the like. Further, the supplement may contain an organic or inorganic carrier material suitable for oral or parenteral administration as well as vitamins, minerals trace elements and other micronutrients in accordance with the recommendations of Government bodies such as the USRDA.

[0002] Embodiments The present invention provides the embodiments according to the following numbered clauses:1. A composition comprising a Bifidobacterium longum transitional microorganism and aHMO mixture consisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose(LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), wherein theBifidobacterium longum transitional microorganism has an Average Nucleotide Identity (ANI)of at least 98% with CNCM I-5942 and / or has at least one identifying characteristic of the B.longum transitional strain deposited under deposit number CNCM I-5942.2. A composition comprising a Bifidobacterium longum transitional microorganism,Bifidobacterium longum subsp. infantis, Bifidobacterium lactis and a HMO mixture consistingof 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3- fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), wherein the Bifidobacterium longum transitional microorganism has an Average Nucleotide Identity (ANI) of at least 98% withCNCM I-5942 and / or has at least one identifying characteristic of the B. longum transitionalstrain deposited under deposit number CNCM I-5942.3. A combination consisting of a Bifidobacterium longum transitional microorganism anda HMO mixture consisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose(LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), wherein theBifidobacterium longum transitional microorganism has an Average Nucleotide Identity (ANI)of at least 98% with CNCM I-5942 and / or has at least one identifying characteristic of the B.longum transitional strain deposited under deposit number CNCM I-5942.4. A combination consisting of a Bifidobacterium longum transitional microorganism,Bifidobacterium longum subsp. infantis, Bifidobacterium lactis and a HMO mixture consistingof 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3- fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), wherein the Bifidobacterium longum transitional microorganism has an Average Nucleotide Identity (ANI) of at least 98% withCNCM I-5942 and / or has at least one identifying characteristic of the B. longum transitionalstrain deposited under deposit number CNCM I-5942.5. The composition or combination according to any one of the preceding clauses,wherein the composition or combination further comprises Bifidobacterium longum subsp. infantis. 6. The composition or combination according to any one of the preceding clases, whereinthe composition or combination further comprises Bifidobacterium lactis.7. The composition or combination according to clause 5 or clause 6, wherein theBifidobacterium longum subsp. infantis is Bifidobacterium longum subsp. infantis LMG 11588or has an Average Nucleotide Identity (ANI) of at least 99.9% to Bifidobacterium longumsubsp. infantis LMG 11588.8. The composition or combination according to clause 6 or clause 7, wherein theBifidobacterium lactis is Bifidobacterium lactis CNCM 1-3446 or has an Average NucleotideIdentity (ANI) of at least 99.9% ANI to Bifidobacterium lactis CNCM 1-3446.9. The composition or combination according to any one of the preceding clauses,wherein the Bifidobacterium longum transitional microorganism is capable of metabolizing oneor more of the HMO(s), preferably all of the HMOs.10. The composition or combination according to any one of the preceding clauses,wherein the Bifidobacterium longum transitional microorganism has an Average NucleotideIdentity (ANI) of at least 99% with Bifidobacterium longum strain deposited with the CNCMunder deposit number CNCM I-5942.11. The composition or combination according to any one of the preceding clauses,wherein the B. longum transitional microorganism is not resistant to any one of tetracyclineand erythromycin.12. The composition or combination according to any one of the preceding clauses,wherein the B. longum transitional microorganism is not resistant to any one of tetracycline,erythromycin, clindamycin and ampicillin.13. The composition or combination according to any one of the preceding clauses,wherein the B. longum transitional microorganism is not resistant to any of tetracycline,erythromycin, clindamycin, ampicillin, gentamycin, streptomycin, chloramphenicol and vancomycin.14. The composition or combination according to any one of clauses 11-13, wherein:(i) lack of resistance to tetracycline is due to absence of a tetracycline resistancegene, suitably a tetW gene which encodes a protein with at least 80% sequence identity to SEQ ID NO: 1 and / or a tetQ which encodes a protein with at least 80% sequence identity to SEQ ID NO: 2; (ii) lack of resistance to erythromycin is due to absence of a erythromycinresistance gene, suitably a Erm49 gene which encodes a protein with at least 80% sequence identity to SEQ ID NO: 3; (iii) lack of resistance to erythromycin and / or clindamycin is due to absence of acorresponding resistance gene, suitably a Erm(X) gene which encodes a protein with at least 80% sequence identity to SEQ ID NO: 4; and / or (iv) lack of resistance to chloramphenicol is due to absence of a chloramphenicolresistance gene, suitably a CrmX gene which encodes a protein with at least 80% sequence identity to SEQ ID NO: 6.15. The composition or combination according to any one of the preceding clauses,wherein the B. longum transitional microorganism comprises a glycosyl hydrolase family43_17 (GH43_17) gene; suitably wherein the GH43_17 gene comprises SEQ ID NO: 7 or a sequence with at least 60% sequence identity to SEQ ID NO: 7.16. The composition or combination according to any one of the preceding clauses,wherein the B. longum transitional microorganism further comprises a major facilitatorsuperfamily (MFS) gene; suitably wherein the MFS gene comprises SEQ ID NO: 37 or a sequence with at least 60% sequence identity to SEQ ID NO: 37.17. The composition or combination according to any one of the preceding clauses,wherein the B. longum transitional microorganism further comprises an AraC gene; suitablywherein the AraC gene comprises SEQ ID NO: 39 or a sequence with at least 60% sequence identity to SEQ ID NO: 39.18. The composition or combination according to clause 17, wherein the GH43_17, MFSand AraC genes are comprised in a gene cluster.19. The composition or combination according to any of clauses 15-18, wherein the B.longum transitional microorganism further comprises one or more of a GH31 gene, and a LacIgene; preferably further comprising a xylulose kinase gene and a xylose isomerase gene.20. The composition or combination according to clause 20, wherein the GH43_17, MFS,AraC, GH31, and LacI genes are comprised in a gene cluster; preferably wherein the GH43_17, MFS, AraC, GH31, LacI, xylulose kinase and xylose isomerase genes are comprised in a gene cluster.21. The composition or combination according to any one of the preeding clauses,wherein the B. longum transitional microorganism further comprises one or more genesencoding for one or more glycoside hydrolases selected from GH43_17, GH43_22, GH43_27, GH43_29, GH121, GH43_24, GH127, GH30_5, GH 43_32 and GH30.22. The composition or combination according to any one of the preeding clauses,wherein the B. longum transitional microorganism further comprises GH29 and GH95 genes.23. The composition or combination according to any one of the preeding clauses,wherein the B. longum transitional microorganism preferentially utilizes 3-fucosyllactose (3-FL).24. The composition or combination according to any one of the preeding clauses,wherein the B. longum transitional microorganism has a growth rate of at least 0.6 k whencultured in the presence of 3-FL.25. The composition or combination according to any one of the preceding clauses,wherein the HMO mixture consists of 2’-FL, DFL, LNT, 6SL and 3SL.26. The composition or combination according to any one of clauses 1-24, wherein theHMO mixture consists of LNFP-I, 2’-FL, DFL, LNT, 6SL and 3SL.27. The composition or combination according to any one clauses 1-24, wherein the HMOmixture consists of 2’-FL, DFL, LNT, 6SL, 3SL, and 3-FL.28. The composition or combination according to any one of clauses 1-24, wherein theHMO mixture consists of LNFP-I, 2’-FL, DFL, LNT, 6SL, 3SL, and 3-FL.29. The composition or combination according to any one of clauses 1-24, wherein theHMO mixture consists of 2’-FL, DFL, LNT, 6SL, 3SL, and LNnT.30. The composition or combination according to any one of clauses 1-24, wherein theHMO mixture consists of LNFP-I, 2’-FL, DFL, LNT, 6SL, 3SL, and LNnT.31. The composition or combination according to any one of clauses 1-24, wherein theHMO mixture consists of 2’-FL, DFL, LNT, 6SL, 3SL, 3-FL and LNnT.32. The composition or combination according to any one of clauses 1-24, wherein theHMO mixture consists of LNFP-I, 2’-FL, DFL, LNT, 6SL, 3SL, 3-FL and LNnT.33. The composition or combination according to any one of clauses 1-25, wherein theHMO mixture consists essentially of: i. 31 wt% to 82 wt% of 2FL, preferably 41wt% to 70 wt%;ii. 10 wt% to 27 wt% of LNT, preferably 14 wt% to 23 wt%;iii. 4 wt% to 11 wt% of DFL, preferably 6 wt% to 10 wt%; andiv. 9 wt% to 34 wt% of 6SL and 3SL combined, preferably 11 wt% to 29 wt%.34. The composition or combination according to any one of clauses 1-24 or 27, whereinthe HMO mixture consists essentially of: i. 16 wt% to 69 wt% of 2’-FL, preferably 22 wt% to 59 wt%;ii. 9 wt% to 24 wt% of LNT, preferably 12 wt% to 21 wt%;iii. 2 wt% to 10 wt% of DFL, preferably 3 wt% to 8 wt%;iv. 8 wt% to 26 wt% of 6SL and 3SL combined, preferably 11 wt% to 22 wt%;and v. 18 wt% to 50 wt% of 3-FL, preferably 11 wt% to 43 wt%.35. The composition or combination according to any one of clauses 1-24 or 28, whereinthe HMO mixture consists or consists essentially of:i. 20 wt% to 46 wt% of 2FL, preferably 22 wt% to 42 wt%;ii. 11 wt% to 17 wt% of LNT, preferably 12 wt% to 15 wt%;iii. 2 wt% to 7 wt% of DFL, preferably 3 wt% to 6 wt%;iv. 9 wt% to 21 wt% of 6SL and 3SL combined, preferably 9 wt% to 19 wt%;v. 9 wt% to 34 wt% of 3FL, preferably 11 wt% to 32 wt%; andvi. 5 wt% to 32 wt% of LNFP-I, preferably 10 wt% to 19 wt%.36. The composition or combination according to any one of clauses 1-24 or 29, whereinthe HMO mixture consists essentially of: i. 34 wt% to 85 wt% of 2’-FL, preferably 40 wt% to 71 wt%;ii. 10 wt% to 40 wt% of LNT, preferably 12 wt% to 26 wt%;iii. 4 wt% to 14 wt% of DFL, preferably 5 wt% to 10 wt%;iv. 9 wt% to 31 wt% of 6SL and 3SL combined, preferably 10 wt% to 28 wt%;and v. 6 wt% to 30 wt% of LNnT, preferably 7 wt% to 22 wt%.37. The composition or combination according to any one of clauses 1-24 or 30, whereinthe HMO mixture consists essentially of: i. 27 wt% to 41 wt% of 2FL, preferably 32 wt% to 39 wt%;ii. 8 wt% to 15 wt% of LNT, preferably 10 wt% to 14 wt%;iii. 4 wt% to 6 wt% of DFL, preferably 4 wt% to 6 wt%;iv. 8 wt% to 18 wt% of 6SL and 3SL combined, preferably 7 wt% to 15 wt%;v. 13 wt% to 21 wt% of LNnT, preferably 16 wt% to 20 wt%; andvi. 7 wt% to 33 wt% of LNFP-I, preferably 11 wt% to 23 wt%.38. The composition or combination according to any one of clauses 1-24 or 31, whereinthe HMO mixture consists essentially of: i. 20 wt% to 60 wt% of 2’-FL, preferably 22 wt% to 55 wt%;ii. 4 wt% to 30 wt% of LNT, preferably 6 wt% to 20 wt%;iii. 1 wt% to 12 wt % of DFL, preferably 2 wt% to 8 wt%;iv. 7 wt% to 23 wt% of 6SL and 3SL combined, preferably 8 wt% to 22 wt%;v. 10 wt% to 50 wt% of 3-FL, preferably 13 wt% to 46 wt%; andvi. 3 wt% to 25 wt% of LNnT, preferably 5 wt% to 20 wt%.39. The composition or combination according to any one of clauses 1-24 or 32, whereinthe HMO mixture consists essentially of: i. 29 wt% to 40 wt% of 2FL, preferably 32 wt% to 39 wt%;ii. 8 wt% to 13 wt% of LNT, preferably 9 wt% to 12 wt%;iii. 3 wt% to 11 wt % of DFL;iv. 3 wt% to 15 wt% of 6SL and 3SL combined, preferably 4 wt% to 15 wt%;v. 11 wt% to 35 wt% of 3FL, preferably 12 wt% to 35 wt%;vi. 1 wt% to 18 wt% of LNnT, preferably 1 wt% to 17 wt%; andvii. 2 wt% to 24 wt% of LNFP-I, preferably 4 wt% to 14 wt%.40. The composition according to any one clauses 1, 2 or 5-39, wherein the compositionfurther comprises a glycan substrate selected from inulin or arabinan.41. The composition according to any one of clauses 1, 2 or 5-40, wherein the compositionis a nutritional composition selected from an infant formula, a starter infant formula, a follow- on or follow-up formula, a baby food, an infant cereal composition, a growing-up-milk, a fortifier such as a human milk fortifier, or a supplement.42. A composition as defined in any one of clauses 1, 2 or 5-41 for use in preventing,reducing the risk of and / or treating an infection in a subject.43. A combination as defined in any one of clauses 3-39 for use in preventing, reducingthe risk of and / or treating an infection in a subject.44. Use of a composition as defined in any one of clauses 1, 2 or 5-41 for the manufactureof a medicament for preventing, reducing the risk of and / or treating an infection in a subject.45. Use of a combination as defined in any one of clauses 3-39 for the manufacture of amedicament for preventing, reducing the risk of and / or treating an infection in a subject.46. A method of preventing, reducing the risk of and / or treating an infection in subject,comprising administering a composition as defined in any one of clauses 1, 2 or 5-41 to thesubject.47. A method of preventing, reducing the risk of and / or treating an infection in subject,comprising administering a combination as defined in any one of clauses 3-39 to the subject.48. A prebiotic for use in preventing, reducing the risk of and / or treating an infection in asubject by promoting the growth and / or survival of a Bifidobacterium longum transitionalmicroorganism in the gut of the subject, wherein the prebiotic is a HMO mixture consisting of2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3- fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), and wherein the Bifidobacteriumlongum transitional microorganism has an Average Nucleotide Identity (ANI) of at least 98%with CNCM I-5942 and / or has at least one identifying characteristic of the B. longumtransitional strain deposited under deposit number CNCM I-5942.49. Use of a prebiotic for the manufacture of a medicament for preventing, reducing therisk of and / or treating an infection in a subject by promoting the growth and / or survival of aBifidobacterium longum transitional microorganism in the gut of the subject, wherein theprebiotic is a HMO mixture consisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL),lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto- N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT),wherein the Bifidobacterium longum transitional microorganism has an Average NucleotideIdentity (ANI) of at least 98% with CNCM I-5942 and / or has at least one identifyingcharacteristic of the B. longum transitional strain deposited under deposit number CNCM I-5942.50. A method of preventing, reducing the risk of and / or treating an infection in a subjectby promoting the growth and / or survival of a Bifidobacterium longum transitionalmicroorganism in the gut of the subject, the method comprising administering a prebiotic tothe subject, wherein the prebiotic is a HMO mixture consisting of 2'-fucosyllactose (2’-FL),difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), wherein the Bifidobacterium longum transitional microorganism has anAverage Nucleotide Identity (ANI) of at least 98% with CNCM I-5942 and / or has at least oneidentifying characteristic of the B. longum transitional strain deposited under deposit numberCNCM I-5942.51. The composition for use, the combination for use, the use, the method, or the prebioticfor use according to any one of clauses 42-50, wherein the composition, combination orprebiotic is for preventing and / or reducing the risk of an infection in the subject.52. The composition for use, the combination for use, the use, the method, or the prebioticfor use according to any one of clauses 42-51, wherein the infection is a viral, bacterial orfungal infection.53. The composition for use, the combination for use, the use, the method, or the prebioticfor use according to any one of clauses 42-52, wherein the infection is an airway infection.54. The composition for use, the combination for use, the use, the method, or the prebioticfor use according to any one of clauses 42-53, wherein the infection is a viral airway infection55. The composition for use, the combination for use, the use, the method, or the prebioticfor use according to clause 54, wherein the viral airway infection is selected from influenzavirus, respiratory syncytial virus, rhinovirus, parainfluenza viruses, metapneumovirus, coronavirus, adenovirus, and bocavirus.56. The composition for use, the combination for use, the use, the method, or the prebioticfor use according to clause 54 or clause 55, wherein the viral airway infection is influenzavirus, respiratory syncytial virus or rhinovirus.57. The composition for use, the combination for use, the use, the method, or the prebioticfor use according to any one of clauses 52-56, wherein the viral infection causes a diseaseselected from the group consisting of common cold, influenza (flu), bronchitis, bronchiolitis and pneumonia, preferably bronchiolitis or pneumonia, more preferably bronchiolitis.58. A composition as defined in any one of clauses 1, 2 or 5-41 for use in promoting along-term immune benefit in a subject.59. A combination as defined in any one of clauses 3-39 for use in promoting a long-termimmune benefit in a subject.60. Use of a composition as defined in any one of clauses 1, 2 or 5-41 for the manufactureof a medicament for promoting a long-term immune benefit in a subject.61. Use of a combination as defined in any one of clauses 3-39 for the manufacture of amedicament for promoting a long-term immune benefit in a subject.62. A method of promoting a long-term immune benefit in a subject comprisingadministering a composition as defined in any one of clauses 1, 2 or 5-41 to the subject.63. A method of promoting a long-term immune benefit in a subject comprisingadministering a combination as defined in any one of clauses 3-39 to the subject.64. The composition for use, the combination for use, the use, or the method according toany one of clauses 58-63, wherein promoting a long-term immune benefit in a subjectcomprises: i. promoting long-term respiratory health;ii. preventing and / or reducing the risk of allergen sensitisation; and / oriii. preventing and / or reducing the risk of developing a respiratory condition.65. A composition as defined in any one of clauses 1, 2 or 5-41 for use in i) preventingand / or reducing the risk of allergen sensitisation and / or ii) preventing and / or reducing the risk of developing a respiratory condition in a subject.66. A combination as defined in any one of clauses 3-39 for use in i) preventing and / orreducing the risk of allergen sensitisation and / or ii) preventing and / or reducing the risk of developing a respiratory condition in a subject.67. Use of a composition as defined in any one of clauses 1, 2 or 5-41 for the manufactureof a medicament for i) preventing and / or reducing the risk of allergen sensitisation and / or ii)preventing and / or reducing the risk of developing a respiratory condition in a subject.68. Use of a combination as defined in any one of clauses 3-39 for the manufacture of amedicament for i) preventing and / or reducing the risk of allergen sensitisation and / or ii)preventing and / or reducing the risk of developing a respiratory condition in a subject.69. A method of i) preventing and / or reducing the risk of allergen sensitisation and / or ii)preventing and / or reducing the risk of developing a respiratory condition in a subject, themethod comprising administering a composition as defined in any one of clauses 1, 2 or 5-41to the subject.70. A method of i) preventing and / or reducing the risk of allergen sensitisation and / or ii)preventing and / or reducing the risk of developing a respiratory condition in a subject, themethod comprising administering a combination as defined in any one of clauses 3-39 to thesubject.71. The composition for use, the combination for use, the use, or the method according toany one of clauses 64-70, wherein the respiratory condition is a chronic inflammatory disease of the respiratory tract or an allergic respiratory tract disease.72. The composition for use, the combination for use, the use, or the method according toclause 71, wherein the chronic inflammatory disease of the respiratory tract is asthma or chronic obstructive pulmonary disease (COPD).73. The composition for use, the combination for use, the use, or the method according toclause 71, wherein the allergic respiratory tract disease is recurrent wheeze or asthma, preferably allergic asthma.74. The composition for use, the combination for use, the use, or the method according toany one of clauses 65-73, wherein the composition and / or combination is for i) preventingand / or reducing the risk of allergen sensitisation in the subject later in life and / or ii) preventing and / or reducing the risk of developing a respiratory condition in the subject later in life.75. A composition as defined in any one of clauses 1, 2 or 5-41 for use in preventing and / orreducing the risk of developing asthma in a subject.76. A combination as defined in any one of clauses 3-39 for use in preventing and / orreducing the risk of developing asthma in a subject.77. Use of a composition as defined in any one of clauses 1, 2 or 5-41 for the manufactureof a medicament for preventing and / or reducing the risk of developing asthma in a subject.78. Use of a combination as defined in any one of clauses 3-39 for the manufacture of amedicament for preventing and / or reducing the risk of developing asthma in a subject.79. A method of preventing and / or reducing the risk of developing asthma in a subjectcomprising administering a composition as defined in any one of clauses 1, 2 or 5-41 to thesubject.80. A method of preventing and / or reducing the risk of developing asthma in a subjectcomprising administering a combination as defined in any one of clauses 3-39 to the subject.81. The composition for use, the combination for use, the use, or the method according toany one of clauses 75-80, wherein the asthma is allergic asthma.82. The composition for use, the combination for use, the use, or the method according toany one of clauses 65-81, wherein the composition is for use in preventing and / or reducing the risk of developing asthma in the subject later in life.83. The composition for use, the combination for use, the use, or the method according toclause 74 or clause 82, wherein later in life is from 12 months to 12 years after termination ofthe treatment.84. The composition for use, the combination for use, the use, the method, or the prebioticfor use according to any one of clauses 42-83, wherein the subject is an infant, a young childor a child.85. The composition for use, the combination for use, the use, the method, or the prebioticfor use according to clause 84, wherein the subject is an infant or a young child.86. The composition for use, the combination for use, the use, the method, or the prebioticfor use according to any one of clauses 42-85, wherein the composition, combination and / orprebiotic increases the levels of IL-6 in the subject.87. The composition for use, the combination for use, the use, the method, or the prebioticfor use according to any one of clauses 42-85, wherein the composition, combination and / orprebiotic increases the levels of short-chain fatty acids (SCFA) in the subject.88. The composition for use, the combination for use, the use, the method, or the prebioticfor use according to clause 87, wherein the SCFA is selected from acetate, butyrate and / orpropionate.89. The composition for use, the combination for use, the use, the method, or the prebioticfor use according to any one of clauses 42-86, wherein the composition, combination and / orprebiotic increases the levels of indole-3-propionic acid in the subject.90. The composition for use, the combination for use, the use, the method, or the prebioticfor use according to any one of clauses 42-89, wherein the composition, combination and / orprebiotic modulates the permeability of the gut epithelial barrier; preferably wherein the composition, combination and / or prebiotic decreases the permeability of the gut epithelial barrier. Those skilled in the art will understand that they can freely combine all features of the present invention disclosed herein. In particular, features described for the product of the present invention may be combined with the method of the present invention and vice versa. Further, features described for different embodiments of the present invention may be combined. Where known equivalents exist to specific features, such equivalents are incorporated as if specifically referred to in this specification. Further advantages and features of the present invention are apparent from the figures and non-limiting examples. ExamplesExample 1: Transitional B. longum increase short-chain fatty acid production3-fucosylactose (3-FL), short-chain fatty acid (SCFA), tricarboxylic acid (TCA) intermediatesand SCFA intermediates were measured by 1H-NMR technique. Results are shown in Figures2 and 3. The heatmaps highlight the dynamic of consumption and production of keymetabolites in SCFAs pathways by showing the Z score of each metabolite abundance at T0, T24 and T48. Total SCFAs corresponds to the sum of the peak integrals of acetate, butyrate, and propionate. Significant difference in metabolite Z score between Bifidobacterium longumtransitional or Bifidobacterium longum spp infantis and no supplementation is calculated withANOVA and highlighted with a star symbol (* p-value<0.05, ** p-value<0.01, *** p-value<0.001). Significant difference in metabolite Z score between Bifidobacterium longumtransitional and Bifidobacterium longum spp infantis is calculated with ANOVA and highlightedwith a round symbol (°p-value<0.05, ° ° p-value<0.01, ° ° ° p-value<0.001). The box plotsindicate the strain abundance (i.e. the strain specificity gene copy measured by qPCR) ofBifidobacterium longum transitional or Bifidobacterium longum spp infantis over 48h orfermentation. Figure 2 and Figure 3 are proofs of concept that Bifidobacterium longumtransitional is well implanted in the microbial community, is metabolically active on 3-FL or Peafiber and produces more SCFAs than Bifidobacterium longum subsp. Infantis.Figure 2 shows SCFAs production (i.e acetate, butyrate and propionate) over 48h of batch fermentation with 3-fucosylactose (3-FL). Figure 3 shows SCFAs production (i.e acetate, butyrate and propionate) over 48h of batch fermentation with pea fiber (rich in arabinan).Example 2: Transitional B. longum increases the anti-infection cytokine, IL-6Monocytes were isolated from the buffy coat of healthy donors. One hundred thousand monocytes were seeded in each well of a 96-well plate and incubated with 1e6 CFU of B.longum transitional for 24 hours for immune training. Cells were washed by centrifugation andallowed to rest for 6 days. Monocytes were stimulated with LPS for 24hrs. IL-6 was thereaftermeasured in the cell culture supernatants to assess immune training (see Figure 4). Barsindicate the median IL-6 production from 3 donors with dotted line indicating the IL-6 level by untrained monocytes. Method Immunoprofiling with PBMC cells Peripheral blood mononuclear cells (PBMC) were isolated from buffy coats obtained from healthy adults by density gradient. PBMC were then seeded at 1.5x106cells / ml in a 48-well bottom plate in complete Isocove’s modified Dulbecco’s medium (cIMDM) containing 10% fetal bovine serum, 1% glutamine, 1% penicillin / streptomycin and 0.1% gentamycin. PBMC were stimulated for 36 hours in the presence of different bacterial strains including alltransitional B longum isolates at 107 CFU / ml and probiotic strains. Cell culture supernatantswere collected to assess cytokine expression for IL-10 and IL-12p40 by ELISA. Standard curve for each cytokine was used to calculate absolute amount (picogram / ml) from optical density readouts.Example 3: Transitional B. longum increases gut epithelial barrier resistanceIn vitro experiments using a human colorectal adenocarcinoma cell line (Caco-2) have shownthat the transitional B.longum strains were able to increase the transepithelial electricalresistance (TEER) when incubated with the epithelial cells. Caco-2 cells were seeded on Transwell and grown for 3 weeks. Caco-2 monolayers were pre-incubated with transitional B. longum NCC5002 (black line) at 4.106 CFU / well, B lactisNCC2818 (grey line) at 4.106 CFU / well or vehicle (dotted line) in the presence of 10ng / mLIFNγ for 24 hours (0-24). After that period, cells were challenged with 50ng / mL TNFα proinflammatory cytokine for another 24 hours (24-48) followed by a recovery phase of 24 hours (48-72). Transepithelial electrical resistance was measured at 0, 24, 48 and 72 hours. Data is represented as mean ± SD. For each time point, statistical difference was assessed using two-way ANOVA with Dunnett test for multiple comparison and represented by asterisks or hash marks for NCC5002 and NCC2818, respectively. * / #= p<0.05; ** / ##=P<0.01 compared to control group (Figure 5). Caco-2 cells were seeded on Transwell and grown for 3 weeks. Caco-2 monolayers were pre-incubated with transitional B. longum NCC5002 (black line) at 4.106 CFU / well, B lactisNCC2818 (grey line) at 4.106 CFU / well or vehicle (dotted line) in the presence of 10ng / mLIFNγ for 24 hours (0-24). After that period, cells were challenged with 50ng / mL TNFα proinflammatory cytokine for another 24 hours (24-48) followed by a recovery phase of 24hours (48-72). At the 72-hour timepoint, permeability of the caco-2 monolayers was assessedby measuring the flux of fluorescein sulfonic acid (478 Daltons) across the epithelium for 180 minutes. Data is represented as mean ± SD. For each time point, statistical difference wasassessed using two-way ANOVA with Dunnett test for multiple comparison and representedby asterisks. *= p<0.05 compared to control group (Figure 6). Method CACO-2 cells culture and transepithelial electrical resistance measurement Caco-2 cells (HTB-37; American Type Culture Collection) were seeded in 24-well semi- permeable inserts. Caco-2 monolayers were cultured for 14 days, with three medium changes / week, until a functional cell monolayer with a transepithelial electrical resistance (TEER) was obtained. Cells were maintained in Dulbecco’s Modified Eagle Medium (DMEM) containing glucose and glutamine and supplemented with HEPES and 20% (v / v) heat- inactivated fetal bovine serum. Before addition of bacteria to the apical compartment, the TEER of the Caco-2 monolayers was measured (= 0h time point). The TEER of an empty insert was subtracted from all readings to account for the residual electrical resistance of aninsert. Then, probiotic strains (directly taken from a glycerol stock) were diluted in Caco-2complete medium and apically added to the Caco-2-bearing inserts at 2x10E6 colony-forming unit. Cells were also exposed to Caco-2 complete medium (CM) in both chambers as control and to 0.75% glycerol in the apical compartment as vehicle control. Cells were treated for 24h and TEER was measured at several time points (2h, 4h, 6h and 24h). After subtracting the TEER of the empty insert, all timepoint values were normalized to its own 0h value (to account for the differences in initial TEER of the different inserts) and are presented as percentage of initial value.Example 4: Analysis of Carbohydrate Active Enzyme (CAZyme) genes ofBifidobacterium longum transitional microorganismGenomes of Bifidobacterium longum subspecies listed in Figure 7 were annotated toCAZymes combining dbCAN2 (Zhang et al., Nucleic Acids Res. 46(W1):W95-W101 (2018))tools and databases HMMdb (v9) and Diamond (v2.0.8). Query sequences with > 0.50 coverage and e-value < 1e-15 were annotated with HMMER according to the dbCAN CAZyme domain HMM database. Diamond was also used to annotate query sequences with hits in theCAZy database (Drula et al., Nucleic Acids Res. 50(D1):D571-D577 (2022))(http: / / www.cazy.org / ) with > 0.90 identity, and e value < 1e-102. HMMER annotation was prioritized and used in instances of mismatched CAZyme annotations of query sequences between HMMER and DIAMOND tools. Only CAZyme families and subfamilies encoding Glycoside Hydrolases (GHs) and Polysaccharide Lyases (PLs) were used for comparativeanalyses of B. longum subspecies (see Figure 7).Example 5: Utilization of glycan substratesPulverized or homogenized stool samples were mixed 10-fold by adding PBS / glycerol (1 / 10)(w / v) before centrifugation at 2000g for 2 minutes. The slurry and pellet were then stored at -80°C. Frozen fecal samples were thawed from storage at -80°C before centrifugation at 2000gfor 2 minutes. The resulting supernatant was inoculated with media based on that disclosedin Daguet et al. (Journal of Functional Foods; 2016; 20; 369-379). This media wassupplemented with specific fibers to be tested at 5 g / L and a Bifidobacteria supplement of5E07 CFU / ml. The culture was set up at 37°C, N2 gas flow to ensure anaerobic conditions and gentle stirring. Aliquots were taken and analyzed at the time points indicated.B. longum transitional strain NCC5001 growth is promoted by pectin (sugar beet) andarabinogalactan (larch wood) (Figure 8).B. longum transitional strain NCC5002 growth is promoted by arabinogalactan (larch wood)and starch (potato) (Figure 9).Example 6: Characterization of B. longum transitional microorganismB. longum transitional strains were isolated from the feces of breast-fed infants using EugonTomato Agar (ETA). Obtained isolates were sequenced using PacBio to obtain a fully closed assembled genome for each of the strain. Each strain was deposited in the internal Nestlé Culture Collection (NCC, Lausanne, Switzerland) and at the Collection Nationale de Microorganisms (CNCM) at the Pasteur Institute (Paris, France) together with their genome sequence data. The genome of the strains was compared by Average Nucleotide Identity (ANI) using OrthoAni (https: / / www.ezbiocloud.net / tools / orthoani) to other publicly availablegenomes representing the overall diversity of the B. longum species (Table 1), and to theMetagenomic Assembled Genomes (MAG) obtained from metagenomic sequences issued from infant feces of the same cohort.Table 1 – list of genomes used for ANI analysis and their publicly available references. (T)stands for typestrain.Taxonomy Strain number Nestlé CultureGenome reference Collection internal numberB. longum CNCM I-5683 NCC 5000 Available at theCNCMB. longum CNCM I-5684 NCC 5001 Available at theCNCMB. longum CNCM I-5685 NCC 5002 Available at theCNCMB. longum CNCM I-5686 NCC 5003 Available at theCNCMB. longum CNCM I-5687 NCC 5004 Available at theCNCMB. longum subsp. suis BSM11-5 NA GCF_001870705.1B. longum subsp. infantis 3_mod NA GCF_902167615.1B. longum subsp. longum JDM301 NA CP002010B. longum BXY01 NA GCF_000730205.1B. longum subsp. longum CMCC_P0001 NA GCF_000410595.1B. longum subsp suillum SU-851 NA GCF_016882605.1B. longum subsp suillum JCM19995 (T) NCC 3079 GCF_017132755B. longum subsp. suis 2074B NA GCF_016759645.1B. longum subsp. suis Su859 (T) NA GCF_900103055.1B. longum subsp. suis DSM-20211 (T) NA GCF_000771285.1B. longum subsp. suis LMG_21814 (T) NA GCF_000741625.1B. longum subsp. suis 209B NA GCF_016759725.1B. longum subsp. suis UMA026 NA PHUM01000001B. longum subsp. suis AGR2137 NA GCF_000421385.1B. longum subsp. longum NCC 2075 NCC 2705 GCF_000007525.1B. longum subsp. longum DJO10A NA GCF_000008945.1B. longum subsp. longum 157F NA GCF_000196575.1B. longum subsp.DSM_20219 (T) NA GCF_900104835.1longum B. longum subsp.JCM_1217 NA GCF_000196555.1longumB. longum subsp infantis ATCC_15697 (T) NA JDTT01000001B. longum subsp infantis Bi-26 NA GCF_004919065.2B. longum subsp infantis JCM_11347 NA CP062951The analysis demonstrates that the newly described strains group together with the MAGs obtained from the same cohort, defining a well delineated clade belonging to the B. longum species. Two previously isolated strains BSM11-5 and 3_mod are found to be grouped withinthis newly described clade. The clade is genetically different from B. longum subspecies longum (96.40 % ANI) subspecies. The clade is related, while still clearly distinct, to B. longum subspecies. suis / suillum (98.207%), and to the group of strains (JDM301, CMCC_P0001 andBXY01) previously suggested to be a new B. longum subspecies (O’Callaghan et al. 2015),sharing an identity of 98.260 % to this group of strains. Figure 1 shows ANI UPGMA basedphylogenetic tree. The scale represents the percentage (%) of identity at each branch point.A selection of the above mentioned genomes, representing the diversity of the B. longumsubspecies, were annotated for Carbohydrate-Active enZYmes(CAZY) using the dbCAN annotation pipeline (http: / / bcb.unl.edu / dbCAN / ). Results showed that B. longum subsp.longum, B. longum subsp. Suis and B. longum subsp.suillum strains contained a GH20 (lacto-N-biosidase) enzyme, implicated in the degradation and metabolization of Lacto-N-tetraose(LNT). Similarly to B. longum subsp. infantis strains, B.longum transitional strains alsopossessed a similar enzyme, and in addition harbored GH29 (fucosidase) encoding genes which are implicated in the degradation and metabolization of fucosylated human milk oligo-saccharides, such as 2’-FL, 3-FL or diFL. Additionally, three of the strains (CNCM I-5684,BSM1-15& 3_mod) also harbor a GH 33 (sialidase) encoding gene implicated in the degradation and metabolization of sialilated HMO such as 3’SL or 6’SL (Table 2).Table 2 – Number of genes encoding for GH20 (lacto-N-biosidase), GH29 (α-fucosi...

Claims

CLAIMS1. A composition comprising a Bifidobacterium longum transitional microorganism and aHMO mixture consisting of 2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally lacto-N-fucopentaose I (LNFP-I), 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), wherein theBifidobacterium longum transitional microorganism has an Average Nucleotide Identity (ANI)of at least 98% with the B. longum transitional strain deposited under deposit number CNCMI-5942 and / or has at least one identifying characteristic of the B. longum transitional straindeposited under deposit number CNCM I-5942.

2. The composition according to claim 1, wherein the Bifidobacterium longum transitionalmicroorganism: (i) is capable of metabolizing the HMO(s); (ii) preferentially utilizes 3-FL over 2’-FL; and / or (iii) is capable of metabolizing a glycan substrate selected from inulin or arabinan.

3. The composition according to claim 1 or claim 2, wherein the Bifidobacterium longumtransitional microorganism has an Average Nucleotide Identity (ANI) of at least 99%,preferably at least 99.9%, with the Bifidobacterium longum strain deposited with the CNCMunder deposit number CNCM I-5942.

4. The composition according to any one of the preceding claims, wherein thecomposition further comprises Bifidobacterium longum subsp. infantis.

5. The composition according to any one of the preceding claims, wherein thecomposition further comprises Bifidobacterium lactis.

6. The composition according to claim 4 or claim 5, wherein:(i) the Bifidobacterium longum subsp. infantis is Bifidobacterium longum subsp. infantisLMG 11588 or has an Average Nucleotide Identity (ANI) of at least 99.9% toBifidobacterium longum subsp. infantis LMG 11588; and (ii) the Bifidobacterium lactis is Bifidobacterium lactis CNCM 1-3446 or has an AverageNucleotide Identity (ANI) of at least 99.9% ANI to Bifidobacterium lactis CNCM 1-3446.

7. The composition according to any one of the preceding claims, wherein the HMOmixture consists of 2’-FL, DFL, LNT, 6SL and 3SL.

8. The composition according to any one of claims 1-6, wherein the HMO mixture consistsessentially of: i. 31 wt% to 82 wt% of 2FL, preferably 41wt% to 70 wt%;ii. 10 wt% to 27 wt% of LNT, preferably 14 wt% to 23 wt%;iii. 4 wt% to 11 wt% of DFL, preferably 6 wt% to 10 wt%; andiv. 9 wt% to 34 wt% of 6SL and 3SL combined, preferably 11 wt% to 29 wt%.

9. The composition according to any one of claims 1-6, wherein the HMO mixture consistsof 2’-FL, DFL, LNT, 6SL, 3SL, and 3-FL.

10. The composition according to any one of claims 1-6, wherein the HMO mixture consistsessentially of: i. 16 wt% to 69 wt% of 2’-FL, preferably 22 wt% to 59 wt%;ii. 9 wt% to 24 wt% of LNT, preferably 12 wt% to 21 wt%;iii. 2 wt% to 10 wt% of DFL, preferably 3 wt% to 8 wt%;iv. 8 wt% to 26 wt% of 6SL and 3SL combined, preferably 11 wt% to 22 wt%;and v. 18 wt% to 50 wt% of 3-FL, preferably 11 wt% to 43 wt%.

11. The composition according to any one of claims 1-6, wherein the HMO mixture consistsof 2’-FL, DFL, LNT, 6SL, 3SL, and LNnT.

12. The composition according to any one of claims 1-6, wherein the HMO mixture consistsessentially of: i. 34 wt% to 85 wt% of 2’-FL, preferably 40 wt% to 71 wt%;ii. 10 wt% to 40 wt% of LNT, preferably 12 wt% to 26 wt%;iii. 4 wt% to 14 wt% of DFL, preferably 5 wt% to 10 wt%;iv. 9 wt% to 31 wt% of 6SL and 3SL combined, preferably 10 wt% to 28 wt%;and v. 6 wt% to 30 wt% of LNnT, preferably 7 wt% to 22 wt%.

13. The composition according to any one of claims 1-6, wherein the HMO mixture consistsof 2’-FL, DFL, LNT, 6SL, 3SL, 3-FL and LNnT.

14. The composition according to any one of claims 1-6, wherein the HMO mixture consistsessentially of: i. 20 wt% to 60 wt% of 2’-FL, preferably 22 wt% to 55 wt%;ii. 4 wt% to 30 wt% of LNT, preferably 6 wt% to 20 wt%;iii. 1 wt% to 12 wt % of DFL, preferably 2 wt% to 8 wt%;iv. 7 wt% to 23 wt% of 6SL and 3SL combined, preferably 8 wt% to 22 wt%;v. 10 wt% to 50 wt% of 3-FL, preferably 13 wt% to 46 wt%; andvi. 3 wt% to 25 wt% of LNnT, preferably 5 wt% to 20 wt%.

15. The composition according to any one of claims 1-6, wherein the HMO mixture consistsof LNFP-I, 2’-FL, DFL, LNT, 6SL, 3SL, and 3-FL.

16. The composition according to any one of claims 1-6, wherein the HMO mixture consistsor consists essentially of:i. 20 wt% to 46 wt% of 2FL, preferably 22 wt% to 42 wt%;ii. 11 wt% to 17 wt% of LNT, preferably 12 wt% to 15 wt%;iii. 2 wt% to 7 wt% of DFL, preferably 3 wt% to 6 wt%;iv. 9 wt% to 21 wt% of 6SL and 3SL combined, preferably 9 wt% to 19 wt%;v. 9 wt% to 34 wt% of 3FL, preferably 11 wt% to 32 wt%; andvi. 5 wt% to 32 wt% of LNFP-I, preferably 10 wt% to 19 wt%.

17. The composition according to any one of claims 1-6, wherein the HMO mixture consistsof LNFP-I, 2’-FL, DFL, LNT, 6SL, 3SL, and LNnT.

18. The composition according to any one of claims 1-6, wherein the HMO mixture consistsessentially of: i. 27 wt% to 41 wt% of 2FL, preferably 32 wt% to 39 wt%;ii. 8 wt% to 15 wt% of LNT, preferably 10 wt% to 14 wt%;iii. 4 wt% to 6 wt% of DFL, preferably 4 wt% to 6 wt%;iv. 8 wt% to 18 wt% of 6SL and 3SL combined, preferably 7 wt% to 15 wt%;v. 13 wt% to 21 wt% of LNnT, preferably 16 wt% to 20 wt%; andvi. 7 wt% to 33 wt% of LNFP-I, preferably 11 wt% to 23 wt%.

19. The composition according to any one of claims 1-6, wherein the HMO mixture consistsof LNFP-I, 2’-FL, DFL, LNT, 6SL, 3SL, 3-FL and LNnT.

20. The composition according to any one of claims 1-6, wherein the HMO mixture consistsessentially of: i. 29 wt% to 40 wt% of 2FL, preferably 32 wt% to 39 wt%;ii. 8 wt% to 13 wt% of LNT, preferably 9 wt% to 12 wt%;iii. 3 wt% to 11 wt % of DFL;iv. 3 wt% to 15 wt% of 6SL and 3SL combined, preferably 4 wt% to 15 wt%;v. 11 wt% to 35 wt% of 3FL, preferably 12 wt% to 35 wt%;vi. 1 wt% to 18 wt% of LNnT, preferably 1 wt% to 17 wt%; andvii. 2 wt% to 24 wt% of LNFP-I, preferably 4 wt% to 14 wt%.

21. The composition according to any one of the preceding claims, wherein the composition is a nutritional composition selected from an infant formula, a starter infant formula, a follow- on or follow-up formula, a baby food, an infant cereal composition, a growing-up-milk, a fortifier such as a human milk fortifier, or a supplement.

22. A composition as defined in any one of claims 1-21 for use in preventing, reducing therisk of and / or treating an infection in a subject.

23. A composition as defined in any one of claims 1-22 for use in promoting a long-termimmune benefit in a subject.

24. The composition for use according to claim 23, wherein promoting a long-term immunebenefit in a subject comprises: i. promoting long-term respiratory health;ii. preventing and / or reducing the risk of allergen sensitisation; and / oriii. preventing and / or reducing the risk of developing a respiratory condition,preferably wherein the respiratory condition is a chronic inflammatory disease of the respiratory tract, such as asthma or chronic obstructive pulmonary disease (COPD) or is an allergic respiratory tract disease, such as recurrent wheeze or asthma.

25. A composition as defined in any one of claims 1-24 for use in preventing and / orreducing the risk of developing asthma in a subject, preferably allergic asthma.

26. A prebiotic for use in preventing, reducing the risk of and / or treating an infection in asubject by promoting the growth and / or survival of a Bifidobacterium longum transitionalmicroorganism in the gut of the subject, wherein the prebiotic is a HMO mixture consisting of2'-fucosyllactose (2’-FL), difucosyllactose (DFL), lacto-N-tetraose (LNT), 6'-sialyllactose (6SL), and 3'-sialyllactose (3SL), and optionally 3-fucosyllactose (3-FL) and / or lacto-N-neotetraose (LNnT), and wherein the Bifidobacterium longum transitional microorganism hasan Average Nucleotide Identity (ANI) of at least 98% with the B. longum transitional straindeposited under deposit number CNCM I-5942 and / or has at least one identifyingcharacteristic of the B. longum transitional strain deposited under deposit number CNCM I-5942.

27. The composition for use according to claim 22 or the prebiotic for use according toclaim 26, wherein the infection is a viral, bacterial or fungal infection, preferably wherein theinfection is an airway infection.

28. The composition for use or the prebiotic for use according to any one of claims 22, 26or 27, wherein the infection is a viral airway infection, preferably wherein the viral airwayinfection is selected from influenza virus, respiratory syncytial virus, rhinovirus, parainfluenzaviruses, metapneumovirus, coronavirus, adenovirus, and bocavirus.

29. The composition for use or the prebiotic for use according to any one of claims 22, 26,27, or 28, wherein the viral airway infection causes a disease selected from the group consisting of common cold, influenza (flu), bronchitis, bronchiolitis and pneumonia, preferably bronchiolitis or pneumonia, more preferably bronchiolitis.

30. The composition for use or the prebiotic for use according to any one of claims 22, 26,27, 28, or 29, wherein the subject is an infant, a young child or a child.

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