Application of bifidobacterium longum transition type microorganism

Abstract

The present invention relates to Bifidobacterium longum transition microorganisms for use in preventing and / or reducing the risk of infection in infants or young children.

Description

Technical Field

[0001] The present invention relates to probiotics and prebiotics, in particular Bifidobacterium longum transitional microorganisms or prebiotics promoting the growth and / or survival of Bifidobacterium longum transitional microorganisms for preventing and / or reducing the risk of infection in infants or young children. Background Art

[0002] The interactions between the immune system and the microbiome play a key role in human health. These interactions begin in the prenatal period and are essential for the maturation of the immune system of newborns and infants. Several factors influence the composition of the infant microbiota and the subsequent development of the immune system. They include maternal infection, antibiotic treatment, environmental exposures, delivery mode, breastfeeding, and food introduction.

[0003] It is known that the regulation of the intestinal microbiota during infancy can be expected to have a significant impact on future health conditions. For example, the intestinal flora can have an impact on the development of a strong immune system, normal growth, and even on the appearance of obesity in the future. However, during the development of an infant, the intestinal microbiota and its evolution are a delicate balance between the presence and reproduction (number) of many intestinal bacterial populations. Regarding the impact of intestinal bacteria on the overall health of infants, some intestinal bacteria are classified as "overall positive", while other intestinal bacteria are "overall negative" (or pathogenic).

[0004] 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 immune imprinting promotes appropriate immune responses to environmental stimuli, including infection.

[0005] There remains a need to develop new strategies for preventing and / or reducing the risk of infection in infants or young children. Summary of the invention

[0006] The present inventors have determined that microorganisms of the subspecies of Bifidobacterium longum of the clade (B. longum transitional type) present in the intestinal microbiome of mammals, particularly humans, during the transitional feeding period can have a beneficial effect on preventing and / or reducing the risk of developing infections. For example, the present inventors have shown that Bifidobacterium longum transitional type microorganisms are able to modulate the levels of protective cytokines (e.g. IL-6) and / or short-chain fatty acids (SCFA); and modulate intestinal barrier permeability, for example after damage or deterioration of intestinal barrier permeability.

[0007] Therefore, in a first aspect, the present invention provides a Bifidobacterium longum transitional microorganism for use in preventing and / or reducing the risk of infection in an infant or young child.

[0008] The present invention also provides a prebiotic for preventing and / or reducing the risk of infection in an infant or young child by promoting the growth and / or survival of a transitional microorganism of Bifidobacterium longum in the intestinal tract of an infant or young child, wherein the prebiotic is: i. a polysaccharide substrate, which is appropriately selected from the group listed in any one of Tables 1 to 3; and / or ii. a human milk oligosaccharide (HMO), which is appropriately selected from the group consisting of 2'-O-fucosyllactose (2'-FL), 3-O-fucosyllactose (3-FL), lactose difucotetraose / difucosyllactose (di-FL), 3'-O-sialyllactose (3'-SL), 6'-O-sialyllactose (6'-SL), lacto-N-tetraose (LNT) and lacto-N-neotetraose (LNnT) and any combination thereof.

[0009] The present invention also provides a combination of a Bifidobacterium longum transitional microorganism and a prebiotic, which is used to prevent and / or reduce the risk of infection in an infant or young child; wherein the prebiotic is: i. a polysaccharide substrate, which is appropriately selected from the group listed in any one of Tables 1 to 3; and / or ii. human milk oligosaccharides (HMO), which are appropriately selected from the group consisting of 2'-O-fucosyllactose (2'-FL), 3-O-fucosyllactose (3-FL), lactose difucotetraose / difucosyllactose (di-FL), 3'-O-sialyllactose (3'-SL), 6'-O-sialyllactose (6'-SL), lactose-N-tetraose (LNT) and lactose-N-neotetraose (LNnT) and any combination thereof.

[0010] The present invention also provides a prebiotic for preventing and / or reducing the risk of infection in infants or young children by promoting the growth of transitional microorganisms of Bifidobacterium longum in the intestinal tract of infants or young children.

[0011] The present invention also provides a combination of a Bifidobacterium longum transitional microorganism and a prebiotic, which is used for preventing and / or reducing the risk of infection in infants or young children. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 - Phylogenetic tree of strains belonging to the species Bifidobacterium longum based on average nucleotide identity (ANI) UPGMA. The scale indicates the percentage of identity at each branch point.

[0013] Figure 2- Production of short-chain fatty acids (SCFAs) (i.e., acetate, butyrate, and propionate) by 48 h batch fermentation with 3-fucosyllactose (3FL). A. Heatmaps showing z-scores of nuclear magnetic resonance (NMR) peak densities of 3FL, TCA cycle, SCFA intermediates, and SCFA. Three conditions were tested, namely fermentation without supplementation, supplementation with a transitional strain of Bifidobacterium longum (NCC5004), or supplementation with infant Bifidobacterium longum (NCC3089). Each condition was performed in triplicate using an infant fecal inoculum. Samples were collected at the start of fermentation (T0), at 24 h (T24), and at the end of fermentation (T48). B. Abundance of transitional strain of Bifidobacterium longum (NCC5004) and infant Bifidobacterium longum (NCC3089) measured by strain-specific qPCR at T0, T24, and T48 of batch fermentation with 3FL.

[0014] Figure 3 - Production of short-chain fatty acids (SCFAs) (i.e., acetate, butyrate, and propionate) by 48-hour batch fermentation with arabinan-rich pea fiber. A. Heatmaps showing z-scores of nuclear magnetic resonance (NMR) peak densities of the TCA cycle, SCFA intermediates, and SCFAs. Three conditions were tested, namely fermentations without supplementation, supplementation with a transitional strain of Bifidobacterium longum (NCC5002), or supplementation with infant Bifidobacterium longum (NCC3089). Each condition was performed in triplicate using an infant fecal inoculum. Samples were collected at the start of fermentation (T0), at 24h (T24), and at the end of fermentation (T48). B. Abundance of transitional strains of Bifidobacterium longum (NCC5002) and infant Bifidobacterium longum (NCC3089) measured by strain-specific qPCR at T0, T24, and T48 of batch fermentations with pea fiber.

[0015] Figure 4 - Interleukin 6 (IL-6) production by monocytes after training with different probiotics and subsequent stimulation with LPS. The bars represent the median IL-6 response and the dashed line represents the IL-6 level of untrained monocytes.

[0016] Figure 5 - Transelement electrical resistance (TEER) of Caco-2 monolayers incubated for 24 h with Bifidobacterium longum NCC5002 (black line), Bifidobacterium lactis NCC2818 (grey line) or vehicle (dashed line) followed by stimulation with pro-inflammatory cytokines.

[0017] Figure 6 - Micromolecule flux across Caco-2 cell monolayers was measured after incubation with transitional B. longum NCC5002 (black line), B. lactis NCC2818 (grey line) or vehicle (dashed line) followed by stimulation with pro-inflammatory cytokines.

[0018] Figure 7 - Graphical representation of glycoside hydrolases (GH) and polysaccharide lyases (PL) in the genomes of the Bifidobacterium longum clade. The heatmap shows the presence (light colors) and absence (dark colors) of GH and PL genes, and the size of the circles represents the number of these genes in each genome of a particular strain.

[0019] Figure 8 - Pectin (sugar beet) and arabinogalactan (larch wood) promote the growth of Bifidobacterium longum transition strain NCC5001 in a complex gut microbiota community. P****<0.0001, ***<0.001, **<0.01, *<0.05, one-way ANOVA with uncorrected Fisher's LSD.

[0020] Fig. 9 - Arabinogalactan (larch wood) and starch (potato) promote the growth of Bifidobacterium longum transition strain NCC5002 in a complex gut microbiota community. P****<0.0001, ***<0.001, **<0.01, *<0.05, one-way ANOVA with uncorrected Fisher's LSD.

[0021] Fig.10 - Representative CAZyme sequences

[0022] Fig.11 - Schematic representation of the organization of genes involved in the degradation and metabolism of fucosylated human milk oligosaccharides in Bifidobacterium longum transitional strains compared to Bifidobacterium longum subsp. infantis ATCC 15697 and Bifidobacterium carinii DSM 21854. Values ​​represent the percentage (%) of identity between different genes.

[0023] Fig.12 - Growth of B. longum transition strain and B. longum subsp. infantis LMG 11588 on glucose, 2'-FL or 3-FL as sole carbon source (0.5% final). Significant differences between 2'-FL and 3-FL growth of each strain were calculated using one-way ANOVA followed by Sidak's multiple comparison test (ns = not significant, *p value < 0.05, **p value < 0.01).

[0024] Fig.13 - Growth ratio of 3-FL relative to 2'-FL of Bifidobacterium longum transition strain and Bifidobacterium longum subsp. infantis LMG 11588.

[0025] Fig.14- Experimental setup schematic diagram of a preclinical model for efficacy testing of a transitional strain of Bifidobacterium longum in an infection model. On postnatal (PND) day 5, C57BL / 6WT pups received different combinations of nutrients (HMO+ probiotic mixtures) via oral gavage, while being fed by mothers fed with a low-fiber diet. From PND16 to PND26, a wide range of antibiotics were supplied through drinking water. After weaning at PND21, a selective fiber mixture (adapted to transitional strains of Bifidobacterium longum) was introduced into the diet of these mice, while oral gavage of the same nutrients (reduced dose of HMO+ probiotic mixtures) was administered. Pneumonia virus infection was performed on mice at PND35. The control group was fed by mothers who were fed only a low-fiber diet (susceptible group) or only a high-fiber diet (protected group) before weaning and kept the same diet after weaning.

[0026] Fig.15 - Kinetics of weight changes in mice after airway virus infection with pneumonia virus from 0 dpi to 10 dpi. Each point represents the mean, and the error bar represents the standard error of the mean, N=8 / experimental group. Statistical differences between different groups were calculated by two-way ANOVA. *, £p value <0.05, **, £p value <0.005, $$$, $$$$p value <0.0001. DETAILED DESCRIPTION

[0027] Unless otherwise indicated, all percentages are by weight.

[0028] As used herein, the terms "about" or "approximately" when referring to a measurable value such as a parameter, amount, duration, etc., are intended to encompass variations of the specified value and variations from the specified value, such as variations of the specified value and variations from the specified value of 1 / -10% or less, 1 / -5% or less, 1 / -1% or less, and + / 0.1% or less, as long as such variations are suitable for making in the disclosed invention. It should be understood that the value referred to by the modifier "about" or "approximately" itself is also specifically and preferably disclosed.

[0029] The terms "subject", "individual" and "patient" are used interchangeably to refer to vertebrates, preferably mammals, more preferably humans. Mammals include, but are not limited to, rodents, apes, humans, farm animals, sports animals and pets.

[0030] The term "infant" means a human subject under 12 months of age or a non-human animal of comparable age.

[0031] As used herein, the term "infant" or "toddler" may refer to a human subject between the ages of 12 months and 5 years. Suitably, "infant" may refer to a non-human animal of comparable age.

[0032] The expressions "supplementary feeding period", "supplementary period", "transitional period", "transitional feeding period" and "weaning period" can be used interchangeably, and refer to the period when milk (breast milk or formula food) is replaced by other foods in the diet of an infant or young child. Usually an infant or young child is gradually transferred or transitioned to a mixed diet comprising milk and / or solid food from exclusive milk feeding (breast milk feeding or formula food feeding). The transitional period depends on the infant or young child, but is usually about 4 months old to about 18 months old, such as about 6 months old to about 18 months old, but can be extended to about 24 months or longer in some cases. For humans, the weaning period usually begins between 4 months and 6 months old, and once an infant and / or young child is no longer fed with breast milk or infant formula food, usually at about 24 months old, it is considered that the weaning period is complete. In some embodiments, the weaning period is 4 months to 24 months.

[0033] The expression "composition" or "nutritional composition" refers to any kind of composition or formulation that provides nutritional benefits to an individual and can be safely consumed by humans or animals. The nutritional composition can be in solid (e.g., powder), semi-solid or liquid form, and can include one or more macronutrients, micronutrients, food additives, water, etc. For example, the nutritional composition can include the following macronutrients: protein source, lipid source, carbohydrate source, and any combination thereof. In addition, the nutritional composition can include the following micronutrients: vitamins, minerals, fiber, phytochemicals, antioxidants, prebiotics, probiotics, bioactive agents, metabolites (e.g., butyrate, docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), gamma-linolenic acid (GLA)), and any combination thereof. The composition may also include food additives, such as stabilizers (when provided in liquid or solid form) or emulsifiers (when provided in liquid form). The amount of various ingredients (e.g., oligosaccharides) can be expressed as g / 100 g of composition on a dry weight basis when the composition is in solid form (e.g., powder), or as a concentration of g / L of composition when the composition refers to a liquid form (the latter also encompasses liquid compositions that can be obtained after reconstitution of the powder in a liquid (such as milk, water), such as reconstituted infant formula or larger / second stage infant formula or infant cereal products or any other formulation designed to provide nutrition for infants or young children). Typically, the nutritional composition can be formulated for enteral, oral, parenteral or intravenous intake, and it typically includes one or more nutrients selected from the following: a lipid or fat source, a protein source, and a carbohydrate source. Preferably, the nutritional composition is for oral use.

[0034] 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 methods.

[0035] As used herein, the expression "infant formula" refers to a food intended for specific nutritional use in the first few months of life for infants and which satisfies the nutritional requirements of such persons in itself (in accordance with Article 2(c) of Council Directive 91 / 321 / EEC 2006 / 141 / EC of 22 December 2006 on infant formula and follow-on formula). It also refers to a nutritional composition intended for infants and as defined in the Codex Alimentarius Commission (Codex STAN 72-1981) and Special Infants (including foods for special medical purposes). The expression "infant formula" covers both "first stage infant formula" and "second stage infant formula" or "follow-on formula".

[0036] "Second infant formula" or "follow-on formula" is given from the 6th month onwards. Infant formula constitutes the main liquid element in the gradually diversified diet of such persons.

[0037] The expression "baby food" refers to a foodstuff intended for specific nutritional use by infants or young children during the first few years of life.

[0038] The expression "infant cereal composition" refers to a foodstuff intended for specific nutritional use by infants or young children during the first years of life.

[0039] The expression "growing-up milk" (or GUM) refers to a milk-based beverage, usually with added vitamins and minerals, which is intended for infants or children.

[0040] The term "fortifier" refers to a liquid or solid nutritional composition suitable for fortifying or admixing human milk, infant formula, growing-up milk, or human breast milk fortified with other nutrients. Thus, the fortifier may be administered after being dissolved in human breast milk, infant formula, growing-up milk, or human breast milk fortified with other nutrients, or it may be administered as a separate composition. When administered as a separate composition, a milk fortifier may also be identified as a "supplement."

[0041] The term "metabolism" is used herein to mean that a substrate can be broken down, adsorbed and / or utilized by a microorganism. For example, a substrate can promote and / or contribute to the growth and / or survival of a microorganism.

[0042] Suitably, the term "capable of metabolizing a glycan substrate" may mean that the transitional strain of Bifidobacterium longum encodes at least one CAZyme that can utilize a glycan substrate. For example, the CAZyme may be able to catalyze the hydrolysis of glycosidic bonds within a glycan substrate. Suitably, the transitional strain of Bifidobacterium longum may encode at least one, at least two, at least three, at least four or at least five CAZymes that can utilize a glycan substrate. Suitably, the term "capable of metabolizing a glycan substrate" may mean that a glycan substrate (or a fiber or component comprising a glycan substrate) can promote the growth and / or survival of the transitional strain of Bifidobacterium longum (e.g., when added to an anaerobic culture of a transitional strain of Bifidobacterium longum). The growth and / or survival of the transitional strain of Bifidobacterium longum can be determined, for example, by measuring the abundance of 16S rDNA using a PCR method. An exemplary test for measuring the growth of a transitional strain of Bifidobacterium longum in the presence of a glycan substrate (e.g., in the form of fiber) is provided in this example.

[0043] Suitably, the polysaccharide substrate can be metabolized by the transitional microorganism of Bifidobacterium longum. Suitably, the polysaccharide substrate may be able to promote the growth and / or survival of the transitional strain of Bifidobacterium longum. The polysaccharide substrate that can promote the growth and / or survival of the transitional strain of Bifidobacterium longum can be determined by the anaerobic culture of the transitional strain of Bifidobacterium longum and the polysaccharide substrate to be tested, for example. The growth and / or survival of the transitional strain of Bifidobacterium longum can be determined by measuring the abundance of bacterial cell number, cell density (for example, by optical density measurement) and / or 16S rDNA, for example, using PCR method. An exemplary test for measuring the growth of the transitional strain of Bifidobacterium longum in the presence of a polysaccharide substrate is provided in the embodiment. The polysaccharide substrate capable of promoting the growth and / or survival of the Bifidobacterium longum transition-type strain may increase the number of Bifidobacterium longum transition-type bacteria in the anaerobic culture by at least 20%, at least 30%, at least 40%, at least 50%, at least 75% or at least 100% compared to the number of Bifidobacterium longum transition-type bacteria in the control anaerobic culture not comprising the HMO. Suitably, the polysaccharide substrate capable of promoting the growth and / or survival of the Bifidobacterium longum transition-type strain may increase the number of Bifidobacterium longum transition-type bacteria in the anaerobic culture by a statistically significant amount (e.g., p-value <0.05 as determined by one-way ANOVA) compared to the number of Bifidobacterium longum transition-type bacteria in the control anaerobic culture not comprising the polysaccharide substrate.

[0044] "Glycan substrate" refers to a polysaccharide that can be metabolized by a microorganism. A polysaccharide substrate can be, for example, a glycoconjugate, an oligosaccharide or a polysaccharide. Glycoconjugate polysaccharides may include N-linked polysaccharides or O-linked polysaccharides within glycoproteins and proteoglycans or glycolipids. For example, O-linked polysaccharides may include proteins or peptides in which the oxygen atom of a serine or threonine residue is connected to a monosaccharide, an oligosaccharide or a polysaccharide, such as in the case of glycosaminoglycans (GAGs). Other examples of "polysaccharide substrates" are cellulose, which is a polysaccharide composed of β-1,4-linked D-glucose, and chitin, which is a polysaccharide composed of β-1,4-linked N-acetyl-D-glucosamine. Polysaccharides may be homopolymers or heteropolymers of monosaccharide residues, and may be linear or branched. "Glycan substrates" as used herein include, for example, oligosaccharides and polysaccharides.

[0045] "Oligosaccharides" may refer to carbohydrates having more than 2 but relatively few monosaccharide units, typically 3, 4, 5, 6, and up to 10. Exemplary oligosaccharides include, but are not limited to, fructooligosaccharides, galacto-oligosaccharides (raffinose, stachyose, verbascose), maltooligosaccharides, gentio-oligosaccharides, cellooligosaccharides, milk oligosaccharides (e.g., those present in mammary secretions), isomaltooligosaccharides, lactofructooligosaccharides, manno-oligosaccharides, melibiose-derived oligosaccharides, pecto-oligosaccharides, xylo-oligosaccharides.

[0046] The term "polysaccharide" may refer to a carbohydrate having more than ten monosaccharide units. Exemplary polysaccharides include, but are not limited to, starch, arabinogalactan, laminarin, chrysophycean, xylan, arabinoxylan, mannan, fucoidan, and galactomannan. It should be understood that there is no precise boundary or distinction between the terms oligosaccharide and polysaccharide, nor is such a distinction necessary to practice the present invention.

[0047] The term "glycosaminoglycan" (GAG) or mucopolysaccharide refers to a long linear polysaccharide composed of repeating disaccharide units (i.e., two sugar units). The repeating disaccharide units consist of an aldose and an amino sugar, except for keratan, which has a galactose in place of the aldose. GAGs are divided into four groups based on the core disaccharide structure.

[0048] As used herein, "mucin" may refer to a family of high molecular weight, heavily glycosylated proteins (glycoconjugates). A key feature of mucins is their ability to form gels; therefore, they are key components in most gel-like secretions, playing roles ranging from lubrication to cell signaling to the formation of mechanical or chemical barriers.

[0049] The term "HMO" refers to human milk oligosaccharides. These carbohydrates are highly resistant to enzymatic hydrolysis, which suggests that they perform important functions that may not be directly related to their caloric value. It has been specifically noted in the art that these carbohydrates play a key role in the early development of infants and young children, such as the maturation of the immune system. Many different types of HMO are found in human milk. Each individual oligosaccharide is based on a combination of glucose, galactose, sialic acid (N-acetylneuraminic acid), fucose and / or N-acetylglucosamine with a variety of bonds between these molecules, so human milk contains a large number of different types of oligosaccharides, and more than 130 such structures have been identified to date. Almost all oligosaccharides have a lactose molecule at the reducing end, and the terminal position of the non-reducing end is occupied by sialic acid and / or fucose (if any). Depending on the presence of fucose and sialic acid in the oligosaccharide structure, HMOs can be divided into non-fucosylated (neutral) or fucosylated (neutral), sialylated (acidic) and non-sialylated molecules, respectively.

[0050] The expression "fucosylated oligosaccharide" refers to an oligosaccharide with a fucose residue. Such oligosaccharides are neutral. 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, fucosyllactose-N-hexaose, fucosyllactose-N-neohexaose, difucosyllactose-N-hexaose I, difucosyllactose-N-neohexaose II, and any combination thereof. Fucosylated oligosaccharides represent the largest fraction of human milk, with 2'-FL accounting for up to 30% of the total HMOs. Fucosylated oligosaccharides are thought to reduce the risk of infection and inflammation and promote the growth and metabolic activity of specific commensal microorganisms, thereby reducing inflammatory responses.

[0051] The expression "N-acetylated oligosaccharide" encompasses "N-acetyllactosamine" and "oligosaccharides comprising N-acetyllactosamine". Such oligosaccharides are neutral oligosaccharides having an N-acetyl-lactosamine residue. Suitable examples are LNT (lactose-N-tetraose), p-lactose-N-neohexose (p-LNnH), LNnT (lactose-N-neotetraose), DSLNT (disialyl lactose-N-tetraose) and any combination thereof. Other examples are lactose-N-hexose, lactose-N-neohexose, p-lactose-N-hexose, p-lactose-N-neohexose, lactose-N-octose, lactose-N-neooctose, iso-lactose-N-octose, p-lactose-N-octose and lactose-N-decasaccharide.

[0052] The expressions "at least one fucosylated oligosaccharide" and "at least one N-acetylated oligosaccharide" are to be understood as "at least one type of fucosylated oligosaccharide" and "at least one type of N-acetylated oligosaccharide".

[0053] The term "sialylated oligosaccharide" refers to an oligosaccharide with charged sialic acid residues. Such oligosaccharides are acidic. Some examples are 3'-sialyllactose (3-SL), 6'-sialyllactose (6-SL), sialyllactose-N-tetraose (Lst, such as Lst-a, Lst-b or Lst-c).

[0054] Suitably, the term "capable of metabolizing an HMO" may mean that the Bifidobacterium longum transitional strain encodes at least one CAZyme that is capable of utilizing an HMO. For example, the CAZyme may be capable of catalyzing the hydrolysis of glycosidic bonds within an HMO. Suitably, the Bifidobacterium 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 an HMO. Suitably, the term "capable of metabolizing an HMO" may mean that the HMO is capable of promoting the growth and / or survival of the Bifidobacterium longum transitional strain (e.g., when added to an anaerobic culture of the Bifidobacterium longum transitional strain). The growth and / or survival of the Bifidobacterium longum transitional strain may be determined, for example, by measuring the abundance of 16S rDNA using a PCR method.

[0055] The term fiber is used herein to refer to carbohydrates that are indigestible to humans or animals. This article also discusses such fibers related to carbohydrates. Suitably, the fiber can be fermented by one or more Bifidobacterium longum transitional microorganisms provided in the uses or compositions of the present invention and / or fermented in one or more regions in the gastrointestinal tract of an organism (such as a human or non-human animal). In the context of the present invention, as used herein, the expression "fiber" or "multiple fibers" or "dietary fiber" or "multiple dietary fibers" refers to the indigestible part of food derived from plants in the small intestine, which includes two main components: soluble fiber, which dissolves in water; and insoluble fiber. A mixture of fibers is included within the scope of the above-mentioned terms. Soluble fiber is easily fermented into gas and physiologically active byproducts in the colon, and can be prebiotics and viscous. Insoluble fiber is insoluble in water, is metabolically inert and swells, or it can be a prebiotic and is metabolized and fermented in the large intestine. Chemically, dietary fiber consists of carbohydrate polymers with three or more monomer units that are not hydrolyzed by endogenous enzymes in the small intestine, such as arabinoxylan, cellulose, and many other plant components, such as resistant starch, resistant dextrin, inulin, lignin, chitin, pectin, arabinan, arabinogalactan, galactan, xylan, beta-glucan and oligosaccharides. Non-limiting examples of dietary fiber are: prebiotic fibers such as oligofructose (FOS), inulin, galacto-oligosaccharides (GOS), fruit fibers, plant fibers, cereal fibers, resistant starches such as high amylose corn starch.

[0056] As used herein, "added fiber" or "added dietary fiber" refers to an ingredient consisting primarily or entirely of fiber that is added to a supplemental nutritional composition, and its content in the fiber contributes to the total fiber content of the composition. The total fiber content of the supplemental nutritional composition is provided by the sum of the amount of fiber naturally present in the ingredients used in the formula (e.g., from whole grain cereal flour) plus the amount of added fiber.

[0057] The term "prebiotic" refers to non-digestible carbohydrates that have beneficial effects on the host by selectively stimulating the growth and / or activity of beneficial bacteria (such as Bifidobacteria in the human colon) (Gibson GR, Roberfroid MB. Dietary modulation of the human colonic microbiota: introducing the concept of prebiotics. J Nutr. 1995; 125: 1401-12).

[0058] The term "probiotic" means a microbial cell preparation or microbial cell component having 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 typically bacteria.

[0059] The term "cfu" is to be understood as colony forming units.

[0060] The “gut microbiome” is the composition of microorganisms (including bacteria, archaea, and fungi) that live in the digestive tract.

[0061] The term "gut microbiome" may include "gut microbiota" and their "activity sites", which may include their structural elements (nucleic acids, proteins, lipids, polysaccharides), metabolites (signaling molecules, toxins, organic and inorganic molecules), and molecules produced by coexisting hosts and structured by surrounding environmental conditions (Berg, G. et al., 2020. Microbiome, 8(1), pp. 1-22).

[0062] Bifidobacterium longum transitional microorganism

[0063] Previously, it has been identified that the longum subspecies microorganism of the evolutionary branch is present in the intestinal microbiome of mammals, especially humans, during the transition feeding period. The longum microorganisms belonging to this evolutionary branch are referred to as transitional longum bifidobacterium (B. longum transitional) in this article. Longum bifidobacterium transitional strains NCC 5000, NCC 5001, NCC5002, NCC 5003 and NCC 5004 are produced by Nestle ( DES PRODUITS SA) was deposited in the French National Collection of Microorganisms (CNCM), Pasteur Institute on May 11, 2021 in accordance with the Budapest Treaty, with the deposit numbers CNCM I-5683, CNCM I-5684, CNCM I-5685, CNCM I-5686 and CNCM I-5687, respectively. In U.S. Provisional Patent Application 63 / 216127, it is shown that the relative abundance of Bifidobacterium longum transitional microorganisms during the transition feeding period (e.g., weaning period) is greater than that of Bifidobacterium infantis (B.infantis) or Bifidobacterium longum long subspecies. In fact, the relative abundance of Bifidobacterium longum infant subspecies decreases at the beginning of the transition feeding period until the end of the transition feeding period, while the abundance of Bifidobacterium longum long subspecies begins to increase. Vatanen et al. demonstrated that this unique Bifidobacterium longum evolutionary branch expanded with the introduction of solid foods and possesses enzymes for utilizing both breast milk and solid food substrates (Vatanen et al.; 2022, Cell 185, 1–18; published online November 1, 2022; https: / / doi.org / 10.1016 / j.cell.2022.10.011).

[0064] Suitably, the Bifidobacterium longum transitional microorganism may encode one or more CAZymes selected from the group listed in Table 1. Suitably, the Bifidobacterium longum transitional microorganism may encode one or two CAZymes selected from the group listed in Table 1.

[0065] Suitably, the Bifidobacterium longum transitional microorganism encodes at least one CAZyme selected from the group listed in Table 1 and one or more of the CAZymes selected from the groups listed in Table 2 and Table 3. For example, the Bifidobacterium longum transitional microorganism may encode at least 2, at least 5, at least 10, at least 20 or at least 30 CAZymes selected from the groups listed in Table 2 and Table 3.

[0066] Suitably, the Bifidobacterium longum transitional microorganism encodes (i) at least one CAZyme selected from the group listed in Table 1 and (ii) each of the CAZymes listed in Table 3 or each of the CAZymes listed in Table 3 except GH5_44.

[0067] Suitably, the Bifidobacterium longum transitional microorganism encodes (i) at least one CAZyme selected from the group listed in Table 1 and (ii) each of the CAZymes listed in Table 3 or each of the CAZymes listed in Table 3 except GH25.

[0068] Suitably, the Bifidobacterium longum transitional microorganism does not encode one or more of the CAZymes listed in Table 4. Suitably, the Bifidobacterium longum transitional microorganism does not encode any of the CAZymes listed in Table 4.

[0069] The Bifidobacterium longum transitional microorganism of the present invention advantageously carries a gene encoding a CAZyme, thereby allowing sialic acid residues to be cleaved from polysaccharides such as sialylated oligosaccharides, glycoproteins and glycolipids. This allows for the effective utilization of sialylated oligosaccharides present in breast milk at the time of weaning, and can therefore participate in the proper development of the intestinal microbiome of infants and / or young children. It may also help prevent the presence of intestinal pathogens.

[0070] In some embodiments, the Bifidobacterium longum transitional microorganism comprises a sialidase or neuraminidase family 33 (GH33, sialidase or neuraminidase) gene having at least 60% identity to the BLON_2348 gene present in Bifidobacterium longum subsp. infantis ATCC15697.

[0071] In some embodiments, the transitional microorganism of Bifidobacterium longum includes about 60%, about 61%, about 62%, about 63%, about 64%, about 65%, about 66%, about 67%, about 68%, about 69%, about 70%, about 71%, about 72%, about 73%, about 74%, about 75%, about 76%, about 77%, about 78%, about 79%, about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, about 99%, about 100%, about 101%, about 102%, about 103%, about 104%, about 105%, about 106%, about 107%, about 108%, about 109%, about 110%, about 111%, about 112%, about 113%, about 114%, about 115%, about 116%, about 117%, about 118%, about 119%, about 120%, about 121%, about 122%, about 123%, about 124%, about 125%, about 126%, about 127%, about 128%, about 129%, about 130%, about 131%, about 132%, about 133%, about 134%, about 135%, about 136%, about 137%, about 138%, about 139%, about 140%, about 141%, about 142%, about 143%, about 144%, about 145%, about 146%, about 147%, about about 8%, about 79%, about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, about 99%, about 100% identical to sialidase or neuraminidase family 33 (GH33, sialidase or neuraminidase) genes.

[0072] In some embodiments, the transitional microorganism of Bifidobacterium longum comprises at least 60%, at least 61%, at least 62%, at least 63%, at least 64%, at least 65%, at least 66%, at least 67%, at least 68%, at least 69%, at least 70%, at least 71%, at least 72%, at least 73%, at least 74%, at least 75%, at least 76%, at least 77%, at least 78%, at least 79%, at least 80%, at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 100%, at least 101%, at least 102%, at least 103%, at least 104%, at least 105%, at least 106%, at least 107%, at least 108%, at least 109%, at least 110%, at least 111%, at least 112%, at least 113%, at least 114%, at least 115%, at least 116%, at least 117%, at least 118%, at least 119%, at least 120%, at least 98%, at least 99%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%, at least 100%,

[0073] In some embodiments, the transitional microorganism of Bifidobacterium longum used according to the present invention comprises: a glycosyl hydrolase family 95 (GH95, α-L-galactosidase; α-L-fucosidase; α-1,2-L-fucosidase) gene, which is at least 60% identical to the BLON_2335 gene present in Bifidobacterium longum subsp. infantis ATCC 15697; and / or a glycosyl hydrolase family 29 (GH29, α-L-fucosidase; α-1,3 / 1,4-L-fucosidase; α-1,2-L-fucosidase), which is at least 60% identical to the BLON_2336 gene present in Bifidobacterium longum subsp. infantis ATCC 15697.

[0074] In some embodiments, the Bifidobacterium longum transitional microorganism used according to the present invention comprises a sialidase or neuraminidase family 33 (GH33, sialidase or neuraminidase) gene having at least 60% identity to the BLON_2348 gene present in Bifidobacterium longum subsp. infantis ATCC 15697.

[0075] In some embodiments, the Bifidobacterium longum transitional microorganism preferentially utilizes 3-fucosyllactose (3-FL) over 2'-fucosyllactose (2'-FL). Suitably, the Bifidobacterium longum transitional microorganism may preferentially utilize 3-FL over 2'-FL at a ratio between 0.1:5, preferably at a ratio between 0.1:4, more preferably at a ratio between 0.2:2.

[0076] In some embodiments, the Bifidobacterium longum transitional microorganisms used in the invention utilize 3-FL more efficiently than 2'-FL, as evidenced by better growth, such as shown in this example.

[0077] In some embodiments, the Bifidobacterium longum transitional microorganism has an average nucleotide identity (ANI) of at least 96% with at least one Bifidobacterium longum strain selected from the group consisting of CNCM I-5683, CNCM I-5684, CNCM I-5685, CNCM I-5686, CNCM I-5687 and CMCC-P0001 (ATCC BAA-2753) and any combination thereof. In some embodiments, the Bifidobacterium longum transitional microorganism has an average nucleotide identity (ANI) of at least 96% with at least one Bifidobacterium longum strain selected from the group consisting of CNCM I-5683, CNCM I-5684, CNCM I-5685, CNCM I-5686, CNCM I-5687 and CMCC-P0001 (ATCC BAA-2753). BAA-2753) and any combination thereof have a B. longum strain having about 96%, 96.1%, 96.2%, 96.3%, 96.4%, 96.5%, 96.6%, 96.7%, 96.8%, 96.9%, 97%, 97.1%, 97.2%, 97.3%, 97.4%, 97.5%, 97.6%, 97.7%, 97.8%, 97.9%, 97.1%, 97.2%, 97.3%, 97.4%, 97.5%, 97.6%, 97.7%, 97.9%, 97.1%, 97.2%, 97.3%, 97.4%, 97.5%, 97.6%, 97.7%, 97.8 ...9%, 97.1%, 97.2%, 97.3%, 97.4%, 97.5%, 97.6%, 97.7%, 97.8%, 97.9%, 97.9%, 97.9%, 97. 8%, 97.9%, 98%, 98.1%, 98.2%, 98.3%, 98.4%, 98.5%, 98.6%, 98.6%, 98.7%, 98.8%, 98.9%, 99%, 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9% or 100% ANI. In some embodiments, the transitional microorganism of Bifidobacterium longum is combined with at least one selected from the group consisting of CNCM I-5683, CNCM I-5684, CNCM I-5685, CNCM I-5686, CNCM I-5687 and CMCC-P0001 (ATCC longum strains consisting of BAA-2753) and any combination thereof have a bioavailability of at least 96%, at least 96.1%, at least 96.2%, at least 96.3%, at least 96.4%, at least 96.5%, at least 96.6%, at least 96.7%, at least 96.8%, at least 96.9%, at least 97%, at least 97.1%, at least 97.2%, at least 97.3%, at least 97.4%, at least 97.5%, at least 97.6%, at least 97.7%, at least 97.8 %, at least 97.9%, at least 98%, at least 98.1%, at least 98.2%, at least 98.3%, at least 98.4%, at least 98.5%, at least 98.6%, at least 98.6%, at least 98.7%, at least 98.8%, at least 98.9%, at least 99%, 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.

[0078] In some embodiments, the Bifidobacterium longum transitional microorganism has an average nucleotide identity (ANI) of at least 98% with at least one Bifidobacterium longum strain selected from the group consisting of CNCM I-5683, CNCM I-5684, CNCM I-5685, CNCM I-5686 and CNCM I-5687 and any combination thereof. Suitably, the Bifidobacterium longum transitional microorganism encodes one or more CAZymes selected from the group listed in Table 1 and has an ANI of at least 98% with at least one Bifidobacterium longum strain selected from the group consisting of CNCM I-5683, CNCM I-5684, CNCM I-5685, CNCM I-5686 and CNCM I-5687 and any combination thereof. Suitably, the Bifidobacterium longum transitional microorganism encodes one or more GH31 CAZymes and has an ANI of at least 98% with at least one Bifidobacterium longum strain selected from the group consisting of CNCM I-5683, CNCM I-5684, CNCM I-5685, CNCM I-5686 and CNCM I-5687 and any combination thereof. In some embodiments, the Bifidobacterium longum transitional microorganism has an ANI of about 98% to 100% with at least one Bifidobacterium longum strain selected from the group consisting of CNCM I-5683, CNCM I-5684, CNCM I-5685, CNCM I-5686 and CNCM I-5687 and any combination thereof. In some embodiments, the Bifidobacterium longum transitional microorganism has an ANI of at least 98%, 98.1%, 98.2%, 98.3%, 98.4%, 98.5%, 98.6%, 98.6%, 98.7%, 98.8%, 98.9%, 99%, 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9% or 100% with at least one Bifidobacterium longum strain selected from the group consisting of CNCM I-5683, CNCM I-5684, CNCM I-5685, CNCM I-5686 and CNCM I-5687 and any combination thereof.In some embodiments, the Bifidobacterium longum transitional microorganism has an ANI of at least 98.6%, at least 98.6%, at least 98.7%, at least 98.8%, at least 98.9%, at least 99%, 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% or at least 100% with at least one Bifidobacterium longum strain selected from the group consisting of CNCM I-5683, CNCM I-5684, CNCM I-5685, CNCM I-5686 and CNCM I-5687 and any combination thereof.

[0079] Methods for sequencing microbial genomes are 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 can be used. For example, suitable metagenomics methods can be performed using shotgun sequencing data. Suitable metagenomics methods are known in the art and include, for example, MetaPhlAn3.0 (see Beghini et al.; eLife 2021; 10: e65088; https: / / huttenhower.sph.harvard.edu / metaphlan) for metagenomics sequencing.

[0080] "Average nucleotide identity (ANI)" is a term in the art that refers to a distance-based method for describing species based on paired comparisons of genomic sequences, and is a computer alternative to the traditional DNA-DNA hybridization (DDH) technology that has been used for phylogenetic definition of species (Goris et al., 2007, "DNA-DNA hybridization 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% correlation will be considered to belong to the same species (see, for example, Wayne et al., 1987, Report of the Ad-Hoc-Committee on Reconciliation of Approaches to Bacterial Systematics. Int J Syst Bacteriol 37: 463-464). ANI is similar to the aforementioned 70% DDH cutoff and can be used for species description. ANI has been evaluated in multiple laboratories and has become the gold standard for species demarcation (see, e.g., Kim et al., 2014, “Towards ataxonomic coherence between average nucleotide identity and 16S rRNA genesequence similarity for species demarcation of prokaryotes”, Int. J. Syst. Evol. Micr. 64:346-351; Richter et al., 2009, “Shifting the genomic goldstandard for the prokaryotic species definition”, P Natl Acad Sci USA 106:19126-19131; and Chan et al., 2012, “Defining bacterial species in the genomic era: insights from the genus Acinetobacter”, Bmc. Microbiol. 12)).

[0081] The ANI of common genes between two known strains is a powerful means of comparing genetic relatedness between strains, and an ANI value of about 95% corresponds to a 70% DNA-DNA hybridization standard for defining species. See, e.g., Konstantinidis and Tiedje, Proc Natl Acad Sci USA, 102(7):2567-72 (2005); and Goris et al., Int Syst Evol Microbiol. 57(Pt 1):81-91 (2007). The ANI between two bacterial genomes is calculated by pairwise comparison of all sequences common between any two strains, and can be determined, for example, using any of a number of publicly available ANI tools, including but not 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 Sci USA 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, KT and Tiedje, JM, Proc. Natl. Acad. Sci. USA, 102: 2567-2572 (2005); and Varghese et al., Nucleic Acids Research, 43(14): 6761-6771 (2015). In a specific embodiment, the ANI between two bacterial genomes can be determined, for example, by averaging the nucleotide identities of homologous genes identified as bidirectional best hits (BBHs). The protein-coding genes of the first genome (genome A) and the second genome (genome B) are compared at the nucleotide level using a similar search tool, such as NSimScan (Novichkov et al., Bioinformatics 32(15): 2380-23811 (2016)). The results are then filtered to retain only BBHs that show 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 percent identity multiplied by the sum of the aligned lengths of all BBHs, divided by the sum of the lengths of the BBH genes. These and ANI determination techniques are known in the art.

[0082] Suitably, the Bifidobacterium longum transitional-type microorganism selected from the group consisting of CNCM I-5683, CNCM I-5684, CNCM I-5685, CNCM I-5686 and CNCM I-5687 represents a reference genome to which the microorganism genome is compared.

[0083] Suitably, the Bifidobacterium longum microorganism selected from the group consisting of CNCM 1-5683, CNCM 1-5684, CNCM 1-5685, CNCM 1-5686, CNCM 1-5687 and CMCC-P0001 (ATCC BAA-2753) represents a reference genome to which the microorganism genome is compared.

[0084] The genome sequences of Bifidobacterium longum transition strains NCC 5000 (CNCM I-5683), NCC 5001 (CNCM I-5684), NCC 5002 (CNCM I-5685), NCC 5003 (CNCM I-5686) and NCC 5004 (CNCM I-5687) are available through the Joint Genome Initiative (JGI) research number Gs0156595 ( https: / / genome.jgi.doe.gov / portal / ). The analysis plan number and taxonomic unit number of each genome are as follows:

[0085] strain JGI Analysis Project JGI Taxa Bifidobacterium longum NCC 5000 Ga0527908 2951181949 Bifidobacterium longum NCC 5001 Ga0529016 2951184202 Bifidobacterium longum NCC 5002 Ga0529017 2951186501 Bifidobacterium longum NCC 5003 Ga0529018 2951188792 Bifidobacterium longum NCC 5004 Ga0529019 2951191018

[0086] In some embodiments, the Bifidobacterium longum transitional microorganism used in the present invention is isolated from a human.

[0087] In some other embodiments, the Bifidobacterium longum transitional microorganism is not the subspecies Bifidobacterium longum subspecies longum or Bifidobacterium longum subspecies infantis.

[0088] Suitably, the Bifidobacterium longum transitional microorganism is provided in the form of a probiotic. Suitably, the Bifidobacterium longum transitional microorganism is provided in a composition.

[0089] Prevent and / or reduce the risk of infection

[0090] As used herein, "infection" may refer to a disease or disorder (including symptoms thereof) caused by an infectious or pathogenic agent.

[0091] As used herein, "prevention" may refer to administering a Bifidobacterium longum transitional microorganism and / or a prebiotic and / or a composition of the present invention to a subject who is not yet infected and / or who does not experience any symptoms of the infection, in order to prevent or attenuate the cause of the disease or to reduce or prevent the development of at least one symptom associated with the disease. A subject may have a predisposition to develop a disease, or a subject may be considered to be at risk of developing a disease.

[0092] "Reducing the risk of infection" may refer to administering a Bifidobacterium longum transitional microorganism and / or a prebiotic and / or a composition of the invention to a subject who is not yet infected and / or who does not experience any symptoms of the infection, to reduce the likelihood that an infant or young child will develop a disease caused by an infectious agent or pathogen. Administration may prevent or attenuate the cause of the disease, or reduce or prevent the development of at least one symptom associated with the disease. A subject may have a predisposition to developing a disease, or a subject may be considered at risk of developing a disease.

[0093] The use of the invention for preventing and / or reducing the risk of infection may be referred to as prophylactic use for delaying or preventing the onset of symptoms of infection and / or reducing the number or severity of symptoms of infection.

[0094] Suitably, administration of a Bifidobacterium longum transitional microorganism and / or a prebiotic and / or a composition of the invention to a subject may reduce the magnitude and / or amount of symptoms of infection caused by an infectious agent or pathogen.

[0095] Suitably, the Bifidobacterium longum transitional microorganism, prebiotic and / or composition of the present invention may be administered to an infant or young child.

[0096] Suitably, the Bifidobacterium longum transitional microorganism, prebiotic and / or composition of the invention may prevent and / or reduce the risk of infection in an infant or young child.

[0097] Suitably, the Bifidobacterium longum transitional microorganism, prebiotic and / or composition of the present invention may be administered to an infant or young child and prevent and / or reduce the risk of infection in the infant or young child.

[0098] The infection can be viral, bacterial, or fungal.

[0099] Suitably, the infection may be a viral airway infection or a viral respiratory tract infection. For example, the infection may be selected from influenza virus infection, respiratory syncytial virus infection, rhinovirus infection, parainfluenza virus infection, metapneumovirus infection, coronavirus infection, adenovirus infection and bocavirus infection.

[0100] Suitably, the infection may be an influenza virus infection, a respiratory syncytial virus infection or a rhinovirus infection.

[0101] Influenza virus is the infectious agent that causes influenza (influenza). Symptoms range from mild to severe, and generally include fever, runny nose, sore throat, muscle pain, headache, cough and fatigue. These symptoms start one to four days (usually two days) after exposure to the virus, and last for about 2 days to 8 days. Diarrhea and vomiting may occur, especially in children. There are four types of influenza viruses, called influenza virus A, influenza virus B, influenza virus C and influenza virus D. Aquatic birds are the main source of influenza A virus (IAV), which is also widely present in various mammals, including humans and pigs. Influenza B virus (IBV) and influenza C virus (ICV) mainly infect humans, and influenza D virus (IDV) is found in cattle and pigs. IAV and IBV circulate in humans and cause seasonal epidemics, while ICV causes mild infections, mainly in children. IDV can infect humans, but has not been found to cause disease. In humans, influenza viruses are mainly spread by respiratory droplets produced by coughing and sneezing. Transmission also occurs via aerosols and intermediate objects and surfaces contaminated with the virus.

[0102] Respiratory syncytial virus (RSV) is a negative-sense single-stranded RNA virus. It is the single most common cause of respiratory hospitalization in infants, with infection rates usually higher during the cold winter months, causing bronchiolitis. RSV spreads through contaminated air droplets and can cause outbreaks in both community and hospital settings. After initial infection via the eyes or nose, the virus will infect epithelial cells of the upper and lower airways, causing inflammation, cell damage, and airway obstruction.

[0103] Rhinoviruses are the most common viral infectious agents in humans and are the main cause of the common cold. Three rhinovirus (A, B and C) species include about 160 recognized types of human rhinoviruses, which differ according to their surface proteins (serotypes). They are lytic in nature and are among the smallest viruses with a diameter of about 30 nanometers. Symptoms of rhinovirus infection can include sore throat, runny nose, nasal congestion, sneezing and coughing; sometimes accompanied by muscle pain, fatigue, malaise, headache, muscle weakness or loss of appetite.

[0104] Suitably, the Bifidobacterium longum transitional microorganism and / or prebiotic is not used to reduce or prevent the presence of enteric pathogens. Suitably, the Bifidobacterium longum transitional microorganism and / or prebiotic is not used to reduce or prevent the presence of enteric pathogens in the intestine of infants and / or young children.

[0105] Suitably, the Bifidobacterium longum transitional microorganism is not used to reduce or prevent the presence of enteric pathogens. Suitably, the Bifidobacterium longum transitional microorganism prebiotic is not used to reduce or prevent the presence of enteric pathogens in the intestine of infants and / or young children.

[0106] Suitably, the Bifidobacterium longum transitional microorganism and / or the prebiotic may increase the level of IL-6 in the infant or young child.

[0107] IL-6 is secreted by macrophages in response to pathogen-associated molecular patterns (PAMPs). Therefore, IL-6 is an important component of fever and acute phase response. In addition, IL-6 is responsible for stimulating acute phase protein synthesis and the production of neutrophils in the bone marrow. It supports the growth of B cells and antagonizes regulatory T cells. IL-6 has been shown to play an important role in the prevention and / or control of many infections, including, for example, vaccinia virus and Listeria monocytogenes (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 et al.; 2001; J Infect Dis; 184(5):610-617) and Candida albicans (van Enckevort et al.; 1999; Med Mycol; 37(6):419-426).

[0108] Suitably, the Bifidobacterium longum transitional microorganism and / or the prebiotic may increase the level of short chain fatty acids (SCFA) in the infant or young child.

[0109] Suitably, the SCFA may be selected from acetate (Acetate, C1 :0), butyrate (Butanonate, C4:0) and / or propionate (Propanoate, C3:0).

[0110] SCFAs are produced when dietary fiber is fermented in the colon. SCFAs have diverse physiological roles in body function; they can affect the production of lipids, energy, and vitamins; influence appetite and cardiometabolic health; and have a blood pressure-lowering effect in experimental models.

[0111] SCFAs have been shown to play an important role in preventing and / or controlling many 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 effect against: RSV (Antunes et al.; Nat Comm; 2019; 10; 3273); influenza virus (Trompette; Immunity; 2018; 48(5); 992-1005 and Moriyama and Ichinobe; PNAS; 2018; 16(8); 3118-3125); viral bronchiolitis (Lynch et al.; J Exp Med; 2018; 215(2); 537-557) and common microbial infections (Schulthess et al.; Immunity; 2019; 50(2); 432-445). Notably, SCFAs produced in the gut influence systemic levels and local SCFA levels in other local organs (e.g., lung).

[0112] The cytokine effect and SCFA effect mediated by the probiotics and / or prebiotics of the present invention can be systemic. Therefore, the cytokine effect (e.g., an increase in the level of IL-6 and / or SCFA) can systemically prevent or reduce the risk of infection as described herein. The cytokine effect may occur locally in the intestinal tract, lungs and / or skin of an infant or young child. Suitably, the SCFA effect can systemically prevent or reduce the risk of infection as described herein. The SCFA effect may occur locally in the intestinal tract, lungs and / or skin of an infant or young child. Suitably, the cytokine or SCFA effect may occur in the intestinal tract of an infant or young child. Suitably, the cytokine or SCFA effect may occur in the lungs of an infant or young child. Therefore, the cytokine or SCFA effect can prevent or reduce the risk of infection in a specific organ or system.

[0113] Suitably, the Bifidobacterium longum transitional microorganism and / or the prebiotic may modulate the permeability of the intestinal epithelial barrier of an infant or young child. Suitably, the Bifidobacterium longum transitional microorganism and / or the prebiotic may reduce the permeability of the intestinal epithelial barrier. An increase in the permeability of the intestinal epithelial barrier may be associated with, for example, an increase in the passage of pathogens across the intestinal epithelium. Thus, a decrease in the permeability of the intestinal epithelial barrier may be associated with, for example, a decrease in the passage of pathogens across the intestinal epithelium.

[0114] Bifidobacterium longum transitional microorganisms and / or prebiotics can reduce and / or prevent the symptoms of infection from worsening. For example, Bifidobacterium longum transitional microorganisms and / or prebiotics can reduce and / or prevent the symptoms caused by inflammation from worsening. Inflammation can be, for example, a pro-inflammatory response to an existing infection. An existing infection can be a current infection or a separate infection caused by a different infectious agent or pathogen. For example, the current example shows that Bifidobacterium longum transitional microorganisms reduce the level of increased permeability in a model of intestinal epithelial barrier function after pro-inflammatory injury. Without wishing to be bound by theory, it is believed that reduced intestinal epithelial barrier permeability after inflammatory injury can reduce the number / level of pathogens that pass through the intestinal epithelial barrier during an inflammatory episode, and thus prevent and / or reduce the risk of infection; and / or prevent and / or reduce the risk of symptoms of an existing infection from worsening.

[0115] Prebiotics

[0116] The present invention also provides a prebiotic for preventing and / or reducing the risk of infection in infants or young children by promoting the growth of transitional microorganisms of Bifidobacterium longum in the intestinal tract of infants or young children, wherein the prebiotic is:

[0117] i. a polysaccharide substrate, which is suitably selected from the group listed in any one of Tables 1 to 3; and / or

[0118] ii. human milk oligosaccharides (HMO), which are suitably selected from 2'-O-fucosyllactose (2'-FL), 3'-O-fucosyllactose (3-FL), lactose difucotetraose / difucosyllactose (di-FL), 3'-O-sialyllactose (3'-SL), 6'-

[0119] The group consisting of O-sialyllactose (6'-SL), lacto-N-tetraose (LNT) and lacto-N-neotetraose (LNnT) and any combination thereof.

[0120] In another aspect, the present invention also provides a prebiotic for preventing and / or reducing the risk of infection in infants or young children by promoting the growth of transitional microorganisms of Bifidobacterium longum in the intestinal tract of infants or young children.

[0121] Glycan Substrates / Carbohydrate-Active Enzymes (CAZymes)

[0122] Bifidobacterium longum transitional microorganisms encode a spectrum of carbohydrate-active enzymes (CAZymes). Without wishing to be bound by theory, it is believed that targeting these CAZymes by, for example, providing suitable glycan substrates in the form of prebiotics may promote the growth and / or survival of Bifidobacterium longum transitional microorganisms in the intestinal microbiota of infants or young children.

[0123] Suitably, promoting the growth and / or survival of Bifidobacterium longum transition-type microorganisms may refer to increasing the number and / or concentration of Bifidobacterium longum transition-type microorganisms in the intestinal microbiota.

[0124] In particular, the CAZyme encoded by each of the transitional strains NCC 5000, NCC 5001, NCC 5002, NCC5003 and NCC 5004 of Bifidobacterium longum, deposited at the Pasteur Institute under the Budapest Treaty on May 11, 2021, with the deposit numbers CNCM I-5683, CNCM I-5684, CNCM I.5685, CNCM I-5686 and CNCM I-5687, respectively, has been determined.

[0125] Carbohydrate-active enzymes (CAZymes) are responsible for the synthesis and degradation of glycoconjugates, oligosaccharides and polysaccharides. They generally correspond to 1%-5% of the genes in living organisms. Glycoconjugates, oligosaccharides and polysaccharides play an important role in many biological functions, for example as structural and energy reserve components, and in many intracellular and intercellular events. The carbohydrate-active enzyme (CAZy) classification is a sequence-based family classification system related to the structure and molecular mechanism of CAZymes (www.cazy.org).

[0126] CAZymes include glycoside hydrolases (GH), glycosyltransferases (GT), polysaccharide lyases (PL), carbohydrate esterases (CE), and carbohydrate binding module families (CBM).

[0127] Suitably, a CAZyme can be a glycoside hydrolase (GH). GH catalyzes 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 glycosidic bonds is catalyzed by two amino acid residues of the enzyme: a common 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.

[0128] The GH classification system is provided by the CAZy classification. Herein, GHs are divided into families (e.g., GH1, GH2, GH3, GH4, etc.) based on molecular function. These families are then further divided into subfamilies based on subgroups found within the family, which share a closer ancestor and are generally more consistent in molecular function (e.g., GH13_1, GH13_2, GH13_3, GH13_4, etc.).

[0129] Table 1 provides detailed information on CAZymes unique to Bifidobacterium longum transitional strains (i.e., not encoded by Bifidobacterium longum suis / suillum, Bifidobacterium longum longum, or Bifidobacterium longuminfantis strains). Table 1 also provides a summary of the glycan substrates metabolized by each CAZyme and exemplary dietary fiber sources / ingredients.

[0130] Table 1

[0131]

[0132]

[0133] Table 2 provides information on the presence of at least one transitional strain of Bifidobacterium longum but not present in the strain selected from Figure 7 Detailed information on a CAZyme in at least one of the group of B. longum suis, B. longum suis, or B. longum infantis strains shown in Table 2. Table 2 also provides a summary of the glycan substrates metabolized by each CAZyme and exemplary dietary fiber sources / ingredients.

[0134] Table 2

[0135]

[0136]

[0137]

[0138]

[0139]

[0140]

[0141] Table 3 provides detailed information on the CAZymes present in all B. longum strains analyzed (i.e., B. longum transitional, B. longum suis, B. longum ssp. longum, and B. longum infantis). Table 3 also provides a summary of the glycan substrates metabolized by each CAZyme and exemplary dietary fiber sources / ingredients.

[0142] Table 3

[0143]

[0144]

[0145]

[0146] Table 4 provides detailed information on CAZymes that are not encoded by the Bifidobacterium longum transitional strain but are encoded by one or more of Bifidobacterium longum subsp. suis, Bifidobacterium longum subsp. longum, and Bifidobacterium longum subsp. infantis.

[0147] Table 4

[0148]

[0149]

[0150] Representative sequences of the CAZymes listed in Tables 1 to 4 are shown in Figure 7 Suitably, the CAZyme referred to in any one of Tables 1 to 4 may include Figure 7 or consisting of the corresponding sequence shown in . Suitably, a CAZyme may include Figure 7 The variants may be or consist of a variant of the corresponding sequence shown in Tables 1 to 4, which retain at least one function of the corresponding CAZyme listed in Tables 1 to 4. Suitably, the variants may provide each of the functional activities of the corresponding CAZyme listed in Tables 1 to 4. Suitably, the variants may include Figure 7 or consisting of an amino acid sequence having at least 70% sequence identity to a sequence listed in Tables 1 to 4, and retaining at least one functional activity, preferably each functional activity, of the corresponding CAZyme listed in Tables 1 to 4. Suitably, the variant may include Figure 7 The variants may be selected from the group consisting of or having amino acid sequences having at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% sequence identity to the corresponding sequences listed in Tables 1 to 4. The variants may retain at least one functional activity, preferably each functional activity, of the corresponding CAZyme listed in Tables 1 to 4.

[0151] Suitably, the prebiotic for use in the present invention may include a polysaccharide substrate selected from the group listed in any one of Tables 1 to 3.

[0152] Suitably, the prebiotic for use in the present invention may include a combination of polysaccharide substrates selected from the group listed in any one of Tables 1 to 3.

[0153] The combination of glycan substrates may include at least 2, at least 4, at least 10, at least 20, at least 30, at least 40, or at least 50 glycan substrates selected from the groups listed in Tables 1 to 3. The combination may include each of the glycan substrates listed in Tables 1 to 3.

[0154] Suitably, the prebiotic may comprise one or more polysaccharide substrates selected from the group listed in Table 1 or Table 2.

[0155] The prebiotic may include at least 2, at least 4, at least 10, at least 20, or at least 30 of the polysaccharide substrates listed in Tables 1 and 2. The prebiotic may include each of the polysaccharide substrates listed in Tables 1 and 2.

[0156] Suitably, the polysaccharide substrate may comprise or consist of pectin, arabinogalactan and / or starch.

[0157] Suitably, the polysaccharide substrate may comprise or consist of pectin.

[0158] Suitably, the polysaccharide substrate may comprise or consist of arabinogalactan.

[0159] Suitably, the polysaccharide substrate may comprise or consist of starch.

[0160] Suitably, the polysaccharide substrate is provided in the form of dietary fiber.For example, the dietary fiber may be a prebiotic fiber.

[0161] Suitably, the glycan substrate may be included in an ingredient, such as a dietary ingredient.

[0162] The ingredient contains one or more polysaccharide substrates which may be selected from the group consisting of purified polysaccharides or purified oligosaccharides, dietary fiber ingredients, semi-purified food ingredients, raw food ingredients, food additives, HMOs, semi-purified or purified peptidoglycans.

[0163] Semi-purified food ingredients can be fruit, vegetable or grain extracts.

[0164] Raw food ingredients can be fruits, vegetables, grains, seaweed or microalgae.

[0165] The food additive may be guar gum or gum arabic.

[0166] Suitably, the peptidoglycan may be a GAG.

[0167] Suitably, the polysaccharide substrate may be included in the purified fibers.

[0168] Exemplary ingredients and / or purified fibers comprising suitable glycan substrates are provided in Tables 1 to 3. In particular, dietary fibers and / or ingredients comprising a given glycan substrate are identified in the same row as the glycan substrate.

[0169] Pectin may be included in fruit or vegetable pectin. Thus, suitable ingredients comprising pectin include, but are not limited to: fruits (e.g., apples, pears), vegetables, legumes (peas), and roots (e.g., sugar beets). Suitable purified fibers comprising arabinogalactans include peach pectin. Suitably, pectin extracted from sugar beets contains arabinan, galactan, and arabinogalactan and may be provided as an ingredient.

[0170] Arabinogalactan may be included in fruit or vegetable pectin. Exemplary suitable ingredients including arabinogalactan include, but are not limited to, fruit, vegetable, whole grain, and seaweed dietary fibers. Suitable purified fibers including arabinogalactan include peach pectin, larch wood arabinogalactan, and gum arabic. Suitably, arabinogalactan may be provided in larch wood arabinogalactan.

[0171] Starch can be included in resistant starch from cereals (whole grain), legumes, vegetables (e.g. corn) and roots (e.g. potato). Exemplary suitable ingredients including starch include, but are not limited to corn. Suitable purified fibers including starch include high amylose starch and resistant dextrins. Suitably, starch can be provided in potato, corn or other ingredients. Suitably, starch can be included in potato ingredients.

[0172] Human milk oligosaccharides (HMO)

[0173] Suitably, the prebiotic comprises an HMO.

[0174] Suitably, HMO can be metabolized by Bifidobacterium longum transitional microorganisms. Suitably, HMO may be able to promote the growth and / or survival of Bifidobacterium longum transitional strains. HMOs that can promote the growth and / or survival of Bifidobacterium longum transitional strains can be determined by, for example, the anaerobic culture of Bifidobacterium longum transitional strains and HMO to be tested. The growth and / or survival of Bifidobacterium longum transitional strains can be determined by measuring the abundance of bacterial cell number, cell density (e.g., by optical density measurement) and / or 16S rDNA, such as using PCR methods. An exemplary test for measuring the growth of Bifidobacterium longum transitional strains in the presence of HMO is provided in this embodiment 6. Compared with the number of Bifidobacterium longum transitional bacteria in the control anaerobic bacteria culture not comprising HMO, the HMOs that can promote the growth and / or survival of Bifidobacterium longum transitional strains can increase the number of Bifidobacterium longum transitional bacteria in the anaerobic culture by at least 20%, at least 30%, at least 40%, at least 50%, at least 75% or at least 100%. Suitably, the HMO capable of promoting the growth and / or survival of a Bifidobacterium longum transitional-type strain may increase the number of Bifidobacterium longum transitional-type bacteria in an anaerobic culture by a statistically significant amount (e.g. p-value <0.05 as determined by one-way ANOVA) compared to the number of Bifidobacterium longum transitional-type bacteria in a control anaerobic culture not comprising the HMO.

[0175] The HMO can be a fucosylated oligosaccharide (i.e., an oligosaccharide having a fucose residue; for example, 2'-fucosyllactose (2-FL), 3-fucosyllactose (3-FL), difucosyllactose (DiFL), lactose-N-fucosylpentaose (e.g., lactose-N-fucosylpentaose I, lactose-N-fucosylpentaose II, lactose-N-fucosylpentaose III, lactose-N-fucosylpentaose V), lactose-N-fucohexose, lactose-N-difucohexose I, fucosyllactose-N-hexose, fucosyllactose-N-neohexose, difucosyllactose-N-hexose I, difucosyllactose-N-neohexose II, and any combination thereof), N-acetylated oligosaccharide. oligosaccharides (e.g., LNT (lactose-N-tetraose), para-lactose-N-neohexose (para-LNnH), LNnT (lactose-N-neotetraose), DSLNT (disialyl lactose-N-tetraose), lactose-N-hexose, lactose-N-neohexose, para-lactose-N-hexose, para-lactose-N-neohexose, lactose-N-octaose, lactose-N-neooctaose, allolactose-N-octaose, para-lactose-N-octaose and lactose-N-decaose and any combination thereof) and / or sialylated oligosaccharides (e.g., 3'-sialyllactose (3-SL), 6'-sialyllactose (6-SL) or Lst (sialyllactose-N-tetraose), Lst-a, Lst-b or Lst-c)).

[0176] The prebiotic may comprise at least one prebiotic oligosaccharide selected from the group consisting of 2'-O-fucosyllactose (2'FL), 3'-O-fucosyllactose (3FL), lactose difucotetraose / difucosyllactose (DFL), 3'-O-sialyllactose (3-SL), 6'-O-sialyllactose (6-SL), lacto-N-tetraose (LNT) and lacto-N-neotetraose (LNnT); and any combination thereof.

[0177] The prebiotic may comprise 34 to 85 wt% 2'-FL, 10 to 40 wt% LNT, 4 to 14 wt% DFL, and 9 to 31 wt% 3-SL and 6-SL combined.

[0178] In some embodiments, the prebiotic comprises

[0179] - 26 to 65% by weight, preferably 32 to 54% by weight, of 2'-FL;

[0180] - 10 to 40% by weight, preferably 11 to 20% by weight, of LNT;

[0181] - 4 to 14% by weight, preferably 4 to 8% by weight, of DFL;

[0182] - 9 to 31 wt. %, preferably 8 to 22 wt. % of 3'-SL and 6'-SL combined; and

[0183] - 12 to 38% by weight, preferably 17 to 31% by weight, of 3-FL.

[0184] The prebiotic may comprise between 0.001 g / L and 12 g / L 2'-FL, preferably between 0.002 g / L and 10 g / L 2'-FL, more preferably between 0.005 g / L and 5 g / L 2'-FL.

[0185] The prebiotic may comprise between 0.001 g / L and 5 g / L DFL, preferably between 0.002 g / L and 4 g / L DFL, more preferably between 4 g / L and 3 g / L DFL.

[0186] The prebiotic may comprise between 0.01 g / L and 6 g / L of LNT, preferably between 0.025 g / L and 5 g / L of LNT, more preferably between 0.05 g / L and 1 g / L of LNT.

[0187] The prebiotic may comprise between 0.001 g / L and 2 g / L 6'-SL, preferably between 0.002 g / L and 1.5 g / L 6'-SL, more preferably between 0.005 g / L and 1 g / L 6'-SL.

[0188] The prebiotic may comprise between 0.01 g / L and 2 g / L 3'-SL, preferably between 0.025 g / L and 1.5 g / L 3'-SL, more preferably between 0.05 g / L and 1 g / L 3'-SL.

[0189] The prebiotic may comprise between 0.01 g / L and 7 g / L 3-FL, preferably between 0.025 g / L and 6 g / L 3-FL, more preferably between 0.05 g / L and 5 g / L 3-FL.

[0190] Suitably, 3'-O-fucosyllactose (3'FL) and lacto-N-tetraose (LNT) contained in the prebiotic promote the growth of Bifidobacterium longum transitional microorganisms which preferentially utilize 3-fucosyllactose (3-FL) rather than 2'-fucosyllactose (2'-FL).

[0191] Combination of Bifidobacterium longum transitional microorganism and prebiotics

[0192] The present invention also provides a combination of a Bifidobacterium longum transitional microorganism and a prebiotic for use according to the present invention.

[0193] The Bifidobacterium longum transitional microorganism and the prebiotic may be administered separately, simultaneously or sequentially.

[0194] Suitably, the Bifidobacterium longum transitional microorganism and the prebiotic may be administered in the form of a combined composition.

[0195] Suitably, the combination of the Bifidobacterium longum transitional microorganism and a prebiotic may be referred to as a "synbiotic".

[0196] In aspects of the invention using a combination of a Bifidobacterium longum transitional microorganism and a prebiotic (e.g., a glycan substrate), each aspect can be selected so that the Bifidobacterium longum transitional microorganism is capable of metabolizing the glycan substrate provided in the combination. Such selection can be performed, for example, by selecting a Bifidobacterium longum transitional microorganism encoding a CAZyme as a glycan substrate (or selecting an ingredient comprising the glycan substrate) from the same row of Tables 1 to 3.

[0197] The combination of the present invention is not limited to requiring that the Bifidobacterium longum transitional microorganism is able to metabolize the glycan substrate provided in the combination. Thus, the present invention encompasses any combination of the Bifidobacterium longum transitional microorganism and the glycan substrate disclosed herein.

[0198] Suitably, the composition comprises one or more glycan substrates as described herein.

[0199] Suitably, the composition comprises a transitional form of Bifidobacterium longum that preferentially utilizes 3-fucosyllactose (3-FL) over 2'-fucosyllactose (2'-FL) mixed with 3'-O-fucosyllactose (3-FL) and lacto-N-tetraose (LNT). The composition may comprise, by dry weight, between 10 3 Up to 10 12 Probiotic strains between 10 cfu, more preferably between 10 7 with 10 12 cfu, such as between 10 8 with 10 10 cfu, the probiotic strain is mixed with 3-Fl, the amount of which is between 0.01g / L and 7g / L 3-FL, preferably between 0.025g / L and 6g / L 3-FL, more preferably between 0.05g / L and 5g / L 3-FL, and mixed with LNT, the amount of which is between 0.01g / L and 6g / L LNT, preferably between 0.025g / L and 5g / L LNT, more preferably between 0.05g / L and 1g / L LNT.

[0200] Composition

[0201] The Bifidobacterium longum transitional microorganism, prebiotic or symbiotic preparation used in the present invention may be provided in the form of a composition.

[0202] The composition can be suitably applied to an individual, such as an infant or young child, in any suitable form such as a nutritional composition of a dosage unit (e.g., tablet, capsule, powder sachet, etc.). The composition can be in powder, semi-liquid or liquid form. The composition can be added to a nutritional composition, infant formula, food composition, supplement, baby food, second stage infant formula, growing milk, infant cereal or fortifier for an infant or young child. In some embodiments, the composition of the present invention is an infant formula, baby food, infant cereal, growing milk, supplement or fortifier that can be used for an infant or young child.

[0203] By way of example, the composition may include other components that may be beneficial in preventing and / or reducing the risk of infection. Additionally or alternatively, the composition may contain other components that may be beneficial during the weaning period.

[0204] Based on dry weight, the transitional microorganism of Bifidobacterium longum can be present in an amount of about 10 3 cfu to 10 12 cfu of probiotic strains, preferably between 107 cfu with 10 12 cfu, such as between 10 8 cfu with 10 10 cfu of the probiotic strain is included in the composition. In one embodiment, the Bifidobacterium longum transitional microorganism is alive. In another embodiment, the Bifidobacterium longum transitional microorganism is non-replicating or inactivated. In some other embodiments, there may be live and inactivated Bifidobacterium longum transitional microorganisms.

[0205] Suitably, the composition comprises one or more glycan substrates as described herein.

[0206] In some embodiments, the composition comprises at least one prebiotic oligosaccharide selected from the group consisting of 2'-O-fucosyllactose (2FL), 3'-O-fucosyllactose (3FL), lactose difucotetraose / difucosyllactose (DFL), 3'-O-sialyllactose (3'-SL), 6'-O-sialyllactose (6'-SL) and lacto-N-tetraose (LNT), and any combination thereof.

[0207] In some embodiments, the composition comprises

[0208] - 26 to 65% by weight, preferably 32 to 54% by weight, of 2'-FL;

[0209] - 10 to 40% by weight, preferably 11 to 20% by weight, of LNT;

[0210] - 4 to 14% by weight, preferably 4 to 8% by weight, of DFL;

[0211] - 9 to 31 wt. %, preferably 8 to 22 wt. % of 3'-SL and 6'-SL combined; and

[0212] - 12 to 38% by weight, preferably 17 to 31% by weight, of 3-FL.

[0213] The composition may comprise between 0.001 g / L and 12 g / L of 2'-FL, preferably between 0.002 g / L and 10 g / L of 2'-FL, more preferably between 0.005 g / L and 5 g / L of 2'-FL.

[0214] The composition may comprise between 0.001 g / L and 5 g / L DFL, preferably between 0.002 g / L and 4 g / L DFL, more preferably between 4 g / L and 3 g / L DFL.

[0215] The composition may comprise between 0.01 g / L and 6 g / L of LNT, preferably between 0.025 g / L and 5 g / L of LNT, more preferably between 0.05 g / L and 1 g / L of LNT.

[0216] The composition may include between 0.001 g / L and 2 g / L 6'-SL, preferably between 0.002 g / L and 1.5 g / L 6'-SL, more preferably between 0.005 g / L and 1 g / L 6'-SL.

[0217] The composition may comprise between 0.01 g / L and 2 g / L 3'-SL, preferably between 0.025 g / L and 1.5 g / L 3'-SL, more preferably between 0.05 g / L and 1 g / L 3'-SL.

[0218] The composition may comprise between 0.01 g / L and 7 g / L of 3-FL, preferably between 0.025 g / L and 6 g / L of 3-FL, more preferably between 0.05 g / L and 5 g / L of 3-FL.

[0219] In some embodiments, the composition comprises a transitional type microorganism of Bifidobacterium longum that preferentially utilizes 3-fucosyllactose (3-FL) rather than 2'-fucosyllactose (2'-FL) mixed with 3'-O-fucosyllactose (3-FL) and lactose-N-tetraose (LNT). On a dry weight basis, the composition may comprise between 10 3 Up to 10 12 Probiotic strains between 10 cfu, more preferably between 10 7 with 10 12 cfu, such as between 10 8 with 10 10 cfu, the probiotic strain is mixed with 3-Fl, the amount of which is between 0.01g / L and 7g / L 3-FL, preferably between 0.025g / L and 6g / L 3-FL, more preferably between 0.05g / L and 5g / L 3-FL, and mixed with LNT, the amount of which is between 0.01g / L and 6g / L LNT, preferably between 0.025g / L and 5g / L LNT, more preferably between 0.05g / L and 1g / L LNT.

[0220] Suitably, 3'-O-fucosyllactose (3'FL) and lacto-N-tetraose (LNT) included in the composition promote the growth of Bifidobacterium longum transitional microorganisms that preferentially utilize 3-fucosyllactose (3-FL) rather than 2'-fucosyllactose (2'-FL).

[0221] method

[0222] In another aspect, the present invention provides a method for preventing and / or reducing the risk of infection in an infant or young child; wherein the method comprises administering an effective amount of a transitional microorganism of Bifidobacterium longum, a prebiotic, or a combination of a transitional microorganism of Bifidobacterium longum and a prebiotic to a subject in need thereof.

[0223] In yet another aspect, the present invention relates to the use of a Bifidobacterium longum transitional microorganism, a prebiotic or a combination of a Bifidobacterium longum transitional microorganism and a prebiotic for the preparation of a medicament for preventing and / or reducing the risk of infection in an infant or young child.

[0224] The Bifidobacterium longum transitional microorganism may be a Bifidobacterium longum transitional microorganism as described herein.

[0225] The prebiotic may be a prebiotic as described herein.

[0226] The combination of a Bifidobacterium longum transitional microorganism and a prebiotic may be provided in any form as described herein. For example, the combination may be provided in a composition as described herein.

[0227] Implementation

[0228] The present invention provides embodiments according to the following numbered clauses:

[0229] 1. A Bifidobacterium longum transitional microorganism for use in preventing and / or reducing the risk of infection in infants or young children.

[0230] 2. A prebiotic for preventing and / or reducing the risk of infection in an infant or young child; wherein the prebiotic is a polysaccharide substrate or a human milk oligosaccharide (HMO).

[0231] 3. A Bifidobacterium longum transitional microorganism for use according to clause 1, wherein the Bifidobacterium longum transitional microorganism is used in combination with a prebiotic selected from a polysaccharide substrate or human milk oligosaccharides (HMO).

[0232] 4. A prebiotic for use according to clause 2, wherein the prebiotic is used in combination with a Bifidobacterium longum transitional microorganism.

[0233] 5. A combination of a Bifidobacterium longum transitional microorganism and a prebiotic for use in preventing and / or reducing the risk of infection in an infant or young child; wherein the prebiotic is selected from a polysaccharide substrate or a human milk oligosaccharide (HMO).

[0234] 6. A Bifidobacterium longum transitional microorganism for use according to any one of clauses 2 to 5, a prebiotic or a combination, wherein the prebiotic is a polysaccharide substrate selected from the group listed in any one of Tables 1 to 3.

[0235] 7. A Bifidobacterium longum transitional microorganism, a prebiotic or a combination for use according to any one of clauses 2 to 5, wherein the prebiotic is a HMO selected from the group consisting of 2'-FL, 3-FL, di-FL, 3'-SL, 6'-SL, LNT and LNnT and any combination thereof.

[0236] 8. A Bifidobacterium longum transitional microorganism, a prebiotic or a combination for use according to any one of clauses 2 to 5, wherein the HMO is 3-FL.

[0237] 9. A Bifidobacterium longum transitional microorganism for use, a prebiotic or a combination according to any one of the preceding clauses, wherein the Bifidobacterium longum transitional microorganism is capable of metabolizing the HMO and / or the glycan substrate.

[0238] 10. A Bifidobacterium longum transitional microorganism for use, a prebiotic or a combination according to any one of the preceding clauses, wherein the Bifidobacterium longum transitional microorganism preferentially utilizes 3'-fucosyllactose (3'-FL) over 2'-fucosyllactose (2'-FL).

[0239] 11. A Bifidobacterium longum transitional microorganism for use, a prebiotic or a combination according to any one of the preceding clauses, wherein the Bifidobacterium longum transitional microorganism is capable of metabolizing a polysaccharide substrate selected from the group listed in any one of Tables 1 to 3.

[0240] 12. A Bifidobacterium longum transitional microorganism, a prebiotic or a combination for use according to any of the preceding clauses, wherein the Bifidobacterium longum transitional microorganism encodes one or more CAZymes selected from the group listed in Table 1, preferably wherein the Bifidobacterium longum transitional microorganism also encodes one or more CAZymes selected from Table 2 and Table 3.

[0241] 13. A Bifidobacterium longum transitional microorganism, a prebiotic or a combination for use according to any of the preceding clauses, wherein the Bifidobacterium longum transitional microorganism has an average nucleotide identity (ANI) of at least 98% with at least one Bifidobacterium longum strain selected from the group consisting of CNCM I-5683, CNCM I-5684, CNCM I-5685, CNCM I-5686, CNCM I-5687, CMCC-P0001 (ATCC BAA-2753) and any combination thereof.

[0242] 14. A Bifidobacterium longum transitional microorganism, a prebiotic or a combination for use according to any of the preceding clauses, wherein the Bifidobacterium longum transitional microorganism has an average nucleotide identity (ANI) of at least 98% with at least one Bifidobacterium longum strain selected from the group consisting of CNCM I-5683, CNCM I-5684, CNCM I-5685, CNCM I-5686, CNCM I-5687 and any combination thereof.

[0243] 16. A Bifidobacterium longum transitional microorganism, a prebiotic or a combination for use according to any one of the preceding clauses, wherein the Bifidobacterium longum transitional microorganism and / or prebiotic increases the level of IL-6 in the infant or young child.

[0244] 17. A Bifidobacterium longum transitional microorganism, a prebiotic or a combination for use according to any one of the preceding clauses, wherein the Bifidobacterium longum transitional microorganism and / or prebiotic increases the level of short chain fatty acids (SCFA) in the infant or young child.

[0245] 18. A Bifidobacterium longum transitional microorganism, a prebiotic or a combination for use according to clause 16, wherein the SCFA is selected from acetate, butyrate and / or propionate.

[0246] 19. A Bifidobacterium longum transitional microorganism, a prebiotic or a combination for use according to any of the preceding clauses, wherein the Bifidobacterium longum transitional microorganism and / or the prebiotic modulates the permeability of the intestinal epithelial barrier; preferably wherein the Bifidobacterium longum transitional microorganism and / or the prebiotic reduces the permeability of the intestinal epithelial barrier.

[0247] 20. A Bifidobacterium longum transitional microorganism, a prebiotic or a combination for use according to any one of the preceding clauses, wherein the infection is a viral infection, a bacterial infection or a fungal infection.

[0248] 21. A Bifidobacterium longum transitional microorganism, a prebiotic or a combination for use according to any one of the preceding clauses, wherein the infection is an airway infection.

[0249] 22. A Bifidobacterium longum transitional microorganism, a prebiotic or a combination for use according to clause 21, wherein the infection is a viral airway infection; suitably selected from influenza virus, respiratory syncytial virus, parainfluenza virus, metapneumovirus, rhinovirus, coronavirus, adenovirus and bocavirus.

[0250] 23. A Bifidobacterium longum transitional microorganism, a prebiotic or a combination for use according to clause 22, wherein the viral airway infection is influenza virus, respiratory syncytial virus or rhinovirus.

[0251] Those skilled in the art will appreciate that they are free to incorporate all features of the present invention disclosed herein. Specifically, features described for product of the present invention may be combined with method of the present invention, and vice versa. In addition, features described for different embodiments of the present invention may be combined. If known equivalents exist for specific features, such equivalents are included, as are clearly mentioned in this specification.

[0252] Further advantages and features of the invention will become apparent upon reference to the accompanying drawings and non-limiting examples.

[0253] Example

[0254] Example 1: Transitional Bifidobacterium longum increases the production of short-chain fatty acids

[0255] 3-fucosyllactose (3FL), short chain fatty acids (SCFA), tricarboxylic acid (TCA) intermediates and SCFA intermediates were measured by 1H-NMR technique. The results are shown in Figure 2 and Figure 3 The heat map highlights the dynamics of consumption and production of key metabolites in the SCFA pathway by displaying the Z-scores of the abundance of each metabolite at T0, T24, and T48.

[0256] Total SCFA corresponds to the sum of the peak integrals of acetate, butyrate and propionate. Significant differences in metabolite Z scores between transitional B. longum or B. longum infantis species and no supplementation were calculated using ANOVA and highlighted with asterisks (*p value < 0.05, **p value < 0.01, ***p value < 0.001). Significant differences in metabolite Z scores between transitional B. longum and B. longum infantis species were calculated using ANOVA and highlighted with circular symbols (°p value < 0.05, °°°p value < 0.01, °°°p value < 0.001). Box plots indicate strain abundance (i.e., strain-specific gene copies measured by qPCR) of transitional B. longum or B. longum infantis species at 48 hours or fermentation. Figure 2 and Figure 3 The concept was proved that transitional B. longum was well embedded in the microbiota, was metabolically active on 3FL or pea fiber, and produced more SCFAs than B. longum subsp. infantis.

[0257] Figure 2 The production of SCFAs (i.e., acetate, butyrate, and propionate) using 3-fucosyllactose (3FL) over 48 h of batch fermentation is shown.

[0258] Figure 3The production of SCFAs (ie acetate, butyrate and propionate) from pea fiber (enriched with arabinan) over 48 h batch fermentation was shown.

[0259] Example 2: Transitional Bifidobacterium longum increases the anti-infection cytokine IL-6

[0260] Monocytes 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 transitional longum B. longum for 24 hours for immune training. The cells were washed by centrifugation and allowed to stand for 6 days. Monocytes were stimulated with LPS for 24 hours. IL-6 was then measured in the cell culture supernatant to assess immune training (see Figure 4 ). Columns indicate the median IL-6 production from 3 donors, dashed line indicates IL-6 levels of untrained monocytes.

[0261] method

[0262] Immune profiling with PBMCs

[0263] Peripheral blood mononuclear cells (PBMCs) were isolated from buffy coats obtained from healthy adults by density gradient. PBMCs were then cultured at 1.5 × 10 6 10 cells / ml were plated in complete Isocove's modified Dulbecco's medium (cIMDM) containing 10% fetal bovine serum, 1% glutamine, 1% penicillin / streptomycin, and 0.1% gentamicin in 48-well plates. PBMCs were stimulated for 36 h in the presence of different bacterial strains, including 10 7 CFU / ml of all transitional B. longum isolates and probiotic strains. Cell culture supernatants were collected to assess cytokine expression of IL-10 and IL-12p40 by ELISA. Standard curves for each cytokine were used to calculate absolute amounts (picograms / ml) from optical density readings.

[0264] Example 3: Transitional Bifidobacterium longum increases intestinal epithelial barrier resistance

[0265] In vitro experiments using a human colorectal adenocarcinoma cell line (Caco-2) have shown that transitional strains of Bifidobacterium longum are able to increase the transmembrane electrical resistance (TEER) when incubated with epithelial cells.

[0266] Caco-2 cells were seeded on Transwell and grown for 3 weeks. Caco-2 monolayers were inoculated with transitional Bifidobacterium longum NCC5002 (black line) (4.10 6 CFU / well), Bifidobacterium lactis NCC2818 (grey line) (4.10 6CFU / well) or vehicle (dashed line) was pre-incubated in the presence of 10ng / mL IFNγ for 24 hours (0-24). After this period, cells were re-stimulated with 50ng / mL TNFα proinflammatory cytokine for 24 hours (24-48), followed by a 24-hour recovery period (48-72). Transmembrane resistance was measured at 0 hours, 24 hours, 48 ​​hours and 72 hours. Data are expressed as mean ± SD. For each time point, statistical differences were assessed using a two-way ANOVA with Dunnett's test for multiple comparisons and are represented by asterisks or hash marks for NCC5002 and NCC2818, respectively. * / # =p<0.05; ** / ## =P<0.01 (compared with the control group) ( Figure 5 ).

[0267] Caco-2 cells were seeded on Transwell and grown for 3 weeks. Caco-2 monolayers were inoculated with transitional Bifidobacterium longum NCC5002 (black line) (4.10 6 CFU / well), Bifidobacterium lactis NCC2818 (grey line) (4.10 6 CFU / well) or vehicle (dashed line) was pre-incubated for 24 hours (0-24) in the presence of 10 ng / mL IFNγ. After this period, cells were re-stimulated with 50 ng / mL TNFα proinflammatory cytokine for 24 hours (24-48), followed by a 24-hour recovery period (48-72). At the 72-hour time point, the permeability of the caco-2 monolayer was assessed by measuring the flux of fluorescein sulfonic acid (478 Daltons) across the epithelium over 180 minutes. Data are expressed as mean ± SD. For each time point, statistical differences were assessed using a two-way ANOVA with Dunnett's test for multiple comparisons and are indicated by asterisks. * = p < 0.05 (compared to the control group) ( Figure 6 ).

[0268] method

[0269] CACO-2 cell culture and transmembrane resistance measurements

[0270] Caco-2 cells (HTB-37; American Type Culture Collection) were seeded in 24-well semipermeable inserts. The Caco-2 monolayer was cultured for 14 days, with the culture medium replaced three times a week until a functional cell monolayer with transmembrane electrical resistance (TEER) was obtained. The cells were maintained in Dulbecco's modified Eagle's medium (DMEM) containing glucose and glutamine and supplemented with HEPES and 20% (v / v) heat-inactivated fetal bovine serum. The TEER of the Caco-2 monolayer was measured (=0 hour time point) before the bacteria were added to the apical compartment. The TEER of the empty insert was subtracted from all readings to calculate the remaining resistance of the insert. The probiotic strain (taken directly from the glycerol stock) was then diluted in Caco-2 complete medium and added to the Caco-2-containing insert toward the top at 2×10E6 colony forming units. Cells were also exposed to Caco-2 complete medium (CM) in both chambers as controls and 0.75% glycerol in the apical compartment as a vehicle control. Cells were treated for 24 hours and TEER was measured at several time points (2 hours, 4 hours, 6 hours and 24 hours). After subtracting the TEER of the empty insert, all time point values ​​were normalized to their own 0 hour value (to account for differences in the initial TEER of different inserts) and expressed as a percentage of the initial value.

[0271] Example 4: Analysis of carbohydrate active enzyme (CAZyme) genes of Bifidobacterium longum transitional microorganisms

[0272] Combining the dbCAN2 (Zhang et al., Nucleic Acids Res. 46(W1):W95-W101(2018)) tool and the databases HMMdb (v9) and Diamond (v2.0.8), Figure 7 The genomes of Bifidobacterium longum subspecies listed in were annotated as CAZymes. 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 the CAZy database (Drula et al., Nucleic Acids Res. 50(D1):D571-D577(2022))(http: / / www.cazy.org / ), identities >0.90, and e-values ​​<1e-102. In case of mismatches in the CAZyme annotations of the query sequences between the HMMER and DIAMOND tools, the HMMER annotation was used preferentially. Only CAZyme families and subfamilies encoding glycoside hydrolases (GH) and polysaccharide lyases (PL) were used for comparative analysis of Bifidobacterium longum subspecies (see Figure 7 ).

[0273] Example 5: Utilization of polysaccharide substrates

[0274] The crushed or homogenized fecal samples were mixed 10 times by adding PBS / glycerol (1 / 10) (w / v) and then centrifuged at 2000g for 2 minutes. The slurry and pellets were then stored at -80°C. The frozen fecal samples were thawed from storage at -80°C before centrifugation at 2000g for 2 minutes. The resulting supernatant was inoculated with a culture medium based on the culture medium disclosed in the following literature: Daguet et al., (Journal of Functional Foods; 2016; 20; 369-379). The culture medium was supplemented with 5g / L of the specific fiber to be tested and 5E07 CFU / ml of bifidobacterium supplement.

[0275] At 37°C, N 2 The cultures were established under a gas flow to ensure anaerobic conditions and gentle agitation. Aliquots were taken at designated time points and analyzed.

[0276] Growth of the transitional strain of Bifidobacterium longum NCC5001 was promoted by pectin (sugar beet) and arabinogalactan (larch wood) ( Figure 8 ).

[0277] Growth of Bifidobacterium longum transition strain NCC5002 was promoted by arabinogalactan (larch wood) and starch (potato) ( Fig. 9 ).

[0278] Example 6: Characterization of Bifidobacterium longum transitional microorganisms

[0279] Bifidobacterium longum transition strains were isolated from the feces of breastfed infants using Eugon tomato agar (ETA). The obtained isolates were sequenced using PacBio to obtain a completely closed assembled genome for each strain. Each strain, together with their genome sequence data, was deposited at the National Collection of Microorganisms (CNCM) at the Nestlé Internal Culture Collection (NCC, Lausanne, Switzerland) and the Pasteur Institute (Paris, France). The genomes of the strains were compared with other publicly available genomes (Table 5) representing the overall diversity of Bifidobacterium longum species by average nucleotide identity (ANI) using OrthoAni (https: / / www.ezbiocloud.net / tools / orthoani), and compared with the metagenome assembly genome (MAG) obtained from the metagenome sequences published in the feces of infants from the same cohort.

[0280] Table 5 - List of genomes used for ANI analysis and their publicly available references. (T) represents the type strain.

[0281]

[0282] The analysis showed that the newly described strains grouped together with MAGs obtained from the same cohort, defining a well-defined clade belonging to the species Bifidobacterium longum. Two previously isolated strains, BSM11-5 and 3_mod, were found to be grouped within this newly described clade. This clade was genetically distinct from the subspecies Bifidobacterium longum subsp. longum (96.40% ANI). This clade was related to, but still distinct from, the group of strains previously shown to be new subspecies Bifidobacterium longum (JDM301, CMCC_P0001 and BXY01) (O'Callaghan et al., 2015), sharing 98.260% identity with this group of strains. Figure 1 A phylogenetic tree based on ANI UPGMA is shown. The scale indicates the percent identity (%) at each branch point.

[0283] The dbCAN annotation pipeline (http: / / bcb.unl.edu / dbCAN / ) was used to annotate the above selection of genomes representing the diversity of B. longum subsp. for carbohydrate active enzymes (CAZY). The results showed that B. longum subsp. longum, B. longum subsp. Suis and B. longum subsp. suillum strains contained the GH20 (lacto-N-biosidase) enzyme involved in the degradation and metabolism of lactose-N-tetraose (LNT). Similar to B. longum subsp. infantis strains, B. longum transition strains also had similar enzymes and additionally carried the GH29 (fucosidase) encoding gene involved in the degradation and metabolism of fucosylated human milk oligosaccharides (such as 2'FL, 3'FL or diFL). In addition, three strains (CNCM 1-5684, BSM1-15 and 3_mod) also carried the GH 33 (sialidase) encoding gene involved in the degradation and metabolism of sialylated HMOs such as 3'SL or 6'SL (Table 6).

[0284] Table 6 - The genomes of each representative encode GH20 (lacto-N-biosidase), GH29 (α-fucosidase), Genes for GH95 (α-fucosidase / α-galactosidase) and GH33 (sialidase) glucose hydroxyhydratase family enzymes quantity.

[0285]

[0286]

[0287] All newly obtained genomes were compared and aligned with the genomes of two strains (Bifidobacterium longum subsp. infantis ATCC15697 and Bifidobacterium carinii DSM 21854), which belong to the species where the genes responsible for fucosylated HMO utilization were elucidated (James et al., 2019).

[0288] result

[0289] like Fig.11 As shown, all newly described strains contain the gene responsible for the utilization of fucosylated HMOs. While the NCC5001 organization reflects the one of Bifidobacterium longum subsp. infantis ATCC 15697, all other strains (NCC 5000, NCC5002, NCC 5003, NCC 5004) carry a gene organization closer to Bifidobacterium carinii DSM 21854. Overall, the similarity to the well-described fucosidase of Bifidobacterium longum subsp. infantis ATCC 15697 was higher than 77% (for BLON_2334) and 88% (BLON_2335) in all newly described strains.

[0290] Example 7: Utilization of fucosylated HMO

[0291] All strains obtained from the Nestle Culture Collection were reactivated from freeze-dried stock solutions using two continuous cultivation steps (16 h, 37 ° C, anaerobic) in MRS supplemented with 0.05% cysteine ​​(MRSc). The reactivated cultures were then centrifuged, washed and resuspended in 1 volume of PBS. The washed cells were used to inoculate a MRS-based medium (MRSc-C) (10 g l-1 bacto proteose peptone n ° 3, 5 g l-1 bacterial yeast extract, 1 g l-1 Tween 80, 2 g l-1 diammonium hydrogen citrate, 5 g l-1 sodium acetate, 0.1 g l-1 magnesium sulfate, 0.05 g l-1 manganese sulfate, 2 g l-1 disodium phosphate, 0.5 g l-1 cysteine) without a carbon source, wherein glucose, 2'FL or 3'FL were added at a concentration of 0.5% as the sole carbon source. Growth was then performed in 96-well microplates with a volume of 200 μl per well. Incubation was performed under anaerobic conditions for 48 h and the optical density was measured at 600 nm in a spectrophotometer. Fig. 9 As shown, all B. longum transition strains grew on fucosylated HMOS.

[0292] result

[0293] All B. longum transition strains grew better on 3'FL than on 2'FL and reached higher cell densities on this carbohydrate. This behavior indicates that 3'FL is superior to 2'FL (ratios of 1.8 to 2.8 - see Fig.12 ), which was not observed in Bifidobacterium longum subsp. infantis LMG 11588.

[0294] Table 7 - List of strains (and corresponding numbers) used for growth studies of individual fucosylated HMOs

[0295]

[0296] Example 8: Preclinical Models for Efficacy Testing of Bliuvenis in Infection Models

[0297] In vivo preclinical models of infection have been developed, e.g. Fig.14 As shown. On postnatal day (PND) 5, C57BL / 6WT pups received different combinations of nutrients (HMO+probiotic mixture) via oral gavage, while being fed by mothers fed a low-fiber diet. A wide range of antibiotics were supplied through drinking water from PND16 to PND26. After weaning on PND21, a selective fiber mixture (adapted to a transitional strain of Bifidobacterium longum) was introduced into the diet of these mice, while the same nutrients (reduced dose of HMO+probiotic mixture) were orally gavaged. The mice were infected with pneumonia virus at PND35. The control group was fed by mothers who were fed only a low-fiber diet (susceptible group) or only a high-fiber diet (protected group) before weaning and maintained the same diet after weaning. As Fig.15 As shown, a nutritional composition containing a mixture of transitional strains of Bifidobacterium longum provided better protection against post-weaning airway virus infection, as shown by weight gain in days post infection (% PND35), when compared to a low fiber diet or a low fiber diet mixture without the transitional strain of Bifidobacterium longum.

[0298] All publications mentioned in the above description are incorporated herein by reference. Various modifications and variations of the method and system of the present invention will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. Although the present invention has been described in conjunction with specific preferred embodiments, it should be understood that the present invention as protected by the claims should not be unduly limited to such specific embodiments. In fact, various modifications to the described modes for carrying out the present invention that are apparent to those skilled in the art of molecular biology or related fields are intended to fall within the scope of the following claims.

[0299] (Original in electronic format)

[0300] (This page is not part of the international application and is not considered a page in the international application)

[0301]

[0302]

[0303] (Original in electronic format)

[0304] (This page is not part of the international application and is not considered a page in the international application)

[0305]

[0306]

[0307] (Original in electronic format)

[0308] (This page is not part of the international application and is not considered a page in the international application)

[0309]

[0310] To be filled in by the receiving office only

[0311]

[0312] To be filled in by the International Bureau only

[0313]

Claims

1. A Bifidobacterium longum transitional microorganism for use in preventing and / or reducing the risk of infection in infants or young children.

2. Prebiotics for preventing and / or reducing the risk of infection in infants or young children; The prebiotic is a polysaccharide substrate or human milk oligosaccharide (HMO).

3. The Bifidobacterium longum transitional microorganism for use according to claim 1, wherein the Bifidobacterium longum transitional microorganism is used in combination with a prebiotic selected from a polysaccharide substrate or human milk oligosaccharides (HMO).

4. The prebiotic for use according to claim 2, wherein the prebiotic is used in combination with a Bifidobacterium longum transitional microorganism.

5. A combination of a Bifidobacterium longum transitional microorganism and a prebiotic for use in preventing and / or reducing the risk of infection in an infant or young child; wherein the prebiotic is selected from a polysaccharide substrate or a human milk oligosaccharide (HMO).

6. The Bifidobacterium longum transitional microorganism, prebiotic or combination for use according to any one of claims 2 to 5, wherein the prebiotic is a polysaccharide substrate selected from the group listed in any one of Tables 1 to 3.

7. Bifidobacterium longum transitional microorganism, prebiotic or combination for use according to any one of claims 2 to 5, wherein the prebiotic is a HMO selected from the group consisting of 2'-FL, 3-FL, di-FL, 3'-SL, 6'-SL, LNT and LNnT and any combination thereof.

8. Bifidobacterium longum transitional microorganism, prebiotic or combination for use according to any one of claims 2 to 5, wherein the HMO is 3-FL.

9. A Bifidobacterium longum transitional microorganism, a prebiotic or a combination for use according to any one of the preceding claims, wherein the Bifidobacterium longum transitional microorganism: (i) is capable of metabolizing the HMO and / or the glycan substrate; (ii) preferentially utilizes 3'-fucosyllactose (3-FL) over 2'-fucosyllactose (2'-FL); (iii) is capable of metabolizing a glycan substrate selected from the group listed in any one of Tables 1 to 3; and / or (iv) encodes one or more CAZymes selected from the group listed in Table 1, preferably wherein the Bifidobacterium longum transitional microorganism also encodes one or more CAZymes selected from Tables 2 and 3.

10. The Bifidobacterium longum transitional microorganism, prebiotic or combination for use according to any one of the preceding claims, wherein the Bifidobacterium longum transitional microorganism has an average nucleotide identity (ANI) of at least 98% with at least one Bifidobacterium longum strain selected from the group consisting of CNCM I-5683, CNCM I-5684, CNCM I-5685, CNCM I-5686, CNCM I-5687, CMCC-P0001 (ATCC BAA-2753) and any combination thereof.

11. Bifidobacterium longum transitional microorganism, prebiotic or combination for use according to any one of the preceding claims, wherein the Bifidobacterium longum transitional microorganism and / or prebiotic: (i) increasing the level of IL-6 in the infant or young child; (ii) increasing the level of short chain fatty acids (SCFA) in the infant or young child, preferably wherein the SCFA is selected from acetate, butyrate and / or propionate; and / or (iii) modulating the permeability of the intestinal epithelial barrier; preferably wherein the Bifidobacterium longum transitional microorganism and / or prebiotic reduces the permeability of the intestinal epithelial barrier.

12. The Bifidobacterium longum transitional microorganism, prebiotic or combination for use according to any one of the preceding claims, wherein the infection is a viral infection, a bacterial infection or a fungal infection.

13. Bifidobacterium longum transitional microorganism, prebiotic or combination for use according to any one of the preceding claims, wherein the infection is an airway infection.

14. A Bifidobacterium longum transitional microorganism, prebiotic or combination for use according to claim 14, wherein the infection is a viral airway infection; suitably selected from influenza virus, respiratory syncytial virus, rhinovirus, parainfluenza virus, metapneumovirus, coronavirus, adenovirus and bocavirus.

Images