Fact-checked by Grok 2 weeks ago

Bifidobacterium

Bifidobacterium is a genus of Gram-positive, anaerobic, non-motile, non-spore-forming bacteria belonging to the phylum Actinobacteria, family Bifidobacteriaceae, and order Bifidobacteriales, characterized by their rod-shaped morphology with a distinctive bifurcated or Y-shaped appearance due to incomplete cell division.^[1]^[2] These bacteria are saccharolytic, fermenting carbohydrates via the unique fructose-6-phosphate phosphoketolase pathway (bifid shunt) to produce primarily acetate and lactate as end products, enabling efficient energy extraction from complex glycans.^[1]^[3] With over 80 recognized species, the genus exhibits high genomic diversity, with genome sizes ranging from 1.73 to 3.16 Mb and G+C content of 59–65%, reflecting adaptations to diverse ecological niches.^[1]^[2]^[4] As prominent commensal members of the mammalian gut microbiota, Bifidobacterium species are among the first microbes to colonize the neonatal intestine, often vertically transmitted from mother to infant, and can constitute up to 90% of the fecal microbiota in breastfed infants due to their ability to metabolize human milk oligosaccharides (HMOs).^[1]^[3] In adults, they typically comprise 3–6% of the gut bacterial population, residing mainly in the colon, where they contribute to microbial stability through cross-feeding interactions that promote the growth of other beneficial taxa like butyrate-producing Firmicutes.^[1]^[2] Their abundance declines with age, diet changes, and conditions like antibiotic use, but certain species persist in the oral cavity, vagina, and fermented dairy products.^[1] Key human-associated species include B. longum (subsp. longum, infantis), B. bifidum, B. breve, B. adolescentis, and B. animalis subsp. _lactis*, each adapted to specific life stages or niches via specialized glycoside hydrolases and adhesins like pili and exopolysaccharides.^[2]^[3] Bifidobacterium species are widely recognized for their probiotic potential, classified as generally recognized as safe (GRAS) by the FDA and qualified presumption of safety (QPS) by the EFSA for strains such as B. adolescentis, B. animalis, B. bifidum, B. breve, and B. longum.^[2] They confer health benefits by modulating the immune system, inhibiting pathogens through production of short-chain fatty acids (SCFAs), bacteriocins, and organic acids, and enhancing gut barrier function, which helps prevent or alleviate conditions like antibiotic-associated diarrhea, irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), and necrotizing enterocolitis in infants.^[1]^[2] Additionally, they support allergy prevention, reduce Helicobacter pylori infection, and promote metabolic health by influencing lipid and glucose homeostasis via gut-brain axis interactions.^[2] Notable probiotic strains include B. animalis subsp. lactis BB-12 and B. longum subsp. infantis 35624, which have been extensively studied in clinical trials for their efficacy in maintaining gastrointestinal regularity and immune balance.^[2]

Taxonomy and Characteristics

Genus Description

Bifidobacterium is a genus of Gram-positive, non-motile, non-spore-forming, anaerobic bacteria classified within the phylum Actinobacteria, order Bifidobacteriales, and family Bifidobacteriaceae. These saccharolytic microorganisms are distinguished by their high G+C content DNA, typically ranging from 55 to 67 mol%.^[5] Members of the genus are ubiquitous inhabitants of the gastrointestinal tracts of various hosts, including mammals, birds, and insects, where they contribute to the microbial community structure.^[6] Morphologically, Bifidobacterium species exhibit pleomorphic rod shapes, often appearing as branched or irregular forms with dimensions typically measuring 0.5–1.3 μm in width and 1.5–8 μm in length.^[5] The characteristic "bifid" appearance, resembling a Y- or V-shape, arises from binary fission that occurs perpendicular to the cell's long axis, leading to distinctive branching patterns observable under microscopy.^[7] Colonies formed on solid media are generally smooth, convex, and white to cream-colored, reflecting their soft, glistening texture. Biochemically, these bacteria are catalase-negative and oxidase-negative, relying on fermentative metabolism that primarily yields lactate and acetate as end products from carbohydrate substrates.

Species Diversity

The genus Bifidobacterium encompasses a diverse array of species, with 109 validly described species and subspecies recognized as of November 2025, reflecting ongoing discoveries from diverse host-associated and environmental niches.^[8] This taxonomic richness has expanded significantly since the early 2000s, driven by advances in molecular identification techniques. Key human-associated species include B. bifidum, which predominates in infant guts; B. longum with its subspecies longum, infantis, and suis, commonly found across human life stages; B. breve, prevalent in early infancy; B. adolescentis, dominant in adults; B. animalis subsp. lactis, often utilized in fermented dairy; B. pseudocatenulatum; and B. catenulatum, both frequent in the adult human intestine.^[9] These species are distinguished by their host specificity, with human clades generally clustering separately from those in animals, such as B. dentium adapted to the human oral cavity and B. boum isolated from ruminant intestines.^[6] Species delineation within Bifidobacterium relies on established prokaryotic taxonomy criteria, including 16S rRNA gene sequencing for initial phylogenetic placement (typically requiring >97% similarity for genus-level assignment), DNA-DNA hybridization (or its modern proxy, average nucleotide identity >95-96%) to confirm species boundaries, and multilocus sequence typing (MLST) using multiple housekeeping genes for higher resolution at the subspecies and strain levels.^[10] These methods have resolved phylogenetic clades that highlight ecological adaptations, such as the Bifidobacterium longum group (encompassing B. longum, B. pseudocatenulatum, and B. catenulatum) versus the B. adolescentis group, which diverged early in the genus's evolution.^[11] At the strain level, significant variations exist within species, influencing probiotic applications through traits like exopolysaccharide (EPS) production for gut adhesion or biofilm formation. Notable examples include B. animalis subsp. lactis BB-12, a widely studied strain known for its robust survival in dairy products and immune-modulating properties, and B. longum subsp. longum BB536, valued for its bile tolerance and potential to alleviate constipation.^[12] These strains exemplify how intraspecies diversity contributes to functional specialization without altering core species traits. Recent taxonomic updates post-2020 have incorporated metagenomic data to propose novel species and reclassifications, expanding the recognized diversity. For instance, metagenome-assembled genomes have identified potential new subspecies within B. longum and B. catenulatum clades, while formally described additions include B. hominis (2025) from human gut isolates^[13] and B. saimiriisciurei (2025) from primate feces,^[14] reflecting broader host range explorations. Additionally, a proposed B. longum subsp. nexus (2025) highlights strain-specific adaptations in adult microbiomes via phylogenomic analysis.^[15] Such updates underscore the role of high-throughput sequencing in refining Bifidobacterium taxonomy beyond traditional culturing.

Biological Properties

Metabolism and Biochemistry

Bifidobacterium species employ a distinctive fermentative metabolism centered on the fructose-6-phosphate shunt, commonly referred to as the bifid shunt, as their primary pathway for hexose sugar catabolism. This pathway diverges from the conventional Embden-Meyerhof-Parnas glycolysis and is mediated by the enzyme fructose-6-phosphate phosphoketolase (F6PPK), which cleaves fructose-6-phosphate into erythrose-4-phosphate and acetyl phosphate. A second phosphoketolase reaction converts xylulose-5-phosphate to glyceraldehyde-3-phosphate and acetyl phosphate, allowing the generation of energy and fermentation products. The overall stoichiometry of the bifid shunt for one glucose molecule is:

\text{Glucose} \rightarrow 1.5 \text{ acetate} + 1 \text{ lactate} + 2.5 \text{ ATP}

This process yields a higher ATP efficiency compared to typical lactic acid fermentation while producing characteristic end products.^[16]^[17] These bacteria preferentially utilize oligosaccharides over monosaccharides, enabling their adaptation to specific ecological niches such as the infant gut. For example, Bifidobacterium longum subsp. infantis hydrolyzes human milk oligosaccharides (HMOs) using specialized glycosyl hydrolases, including those from GH families 2 (β-galactosidases), 20 (β-N-acetylhexosaminidases), 29 (α-L-fucosidases), and 95 (α-L-fucosidases), which cleave fucose and other residues to release fermentable sugars. Other species ferment prebiotics like fructooligosaccharides (FOS), galactooligosaccharides (GOS), and inulin through similar enzymatic mechanisms, prioritizing these complex carbohydrates for growth. The fermentation end products are primarily acetate and lactate in a molar ratio of approximately 3:2, with no gas formation and negligible ethanol production; certain strains also generate short-chain fatty acids (SCFAs) such as propionate via alternative routes or cross-feeding interactions.^[18]^[19]^[16] Bifidobacterium species exhibit complex nutritional requirements, necessitating growth media enriched with peptides for amino acid supply, as they are auxotrophic for multiple amino acids including cysteine, serine, and others varying by strain. They are also dependent on exogenous vitamins such as pantothenate and riboflavin, reflecting limitations in de novo biosynthesis pathways. Recent advances in metabolic engineering, reported in studies from 2023 to 2025, have focused on modifying Bifidobacterium strains to boost SCFA production—particularly acetate and propionate—in synbiotic applications, enhancing their potential for targeted gut modulation.^[20]^[21]^[22]

Oxygen Tolerance and Growth Conditions

Bifidobacterium species are classified as strict anaerobes, yet many exhibit aerotolerance, enabling survival in low-oxygen environments up to 2-5% O₂. This tolerance is facilitated by enzymes such as flavoproteins, NADH oxidases, and superoxide dismutase (SOD), which help manage reactive oxygen species (ROS). Notably, these bacteria lack catalase activity, resulting in the accumulation of hydrogen peroxide (H₂O₂) as a byproduct of NADH oxidase-mediated oxygen reduction, which can limit prolonged exposure.^[23]^[24] Optimal growth conditions for Bifidobacterium occur at temperatures of 37-40°C, pH levels between 6.5 and 7.0, and under strict anaerobiosis with a redox potential (Eh) below -200 mV. Some strains, such as B. animalis, display microaerophilic characteristics, tolerating brief exposure to air without significant viability loss. These parameters mimic the anaerobic gut environment, supporting robust proliferation in laboratory and industrial settings.^[25]^[26]^[27] Viability during cultivation and storage is enhanced by protectants like cysteine and ascorbic acid, which act as reducing agents to scavenge oxygen and maintain low Eh in media. Additionally, tolerance to bile salts—a key gut stressor—is mediated by efflux pumps, such as those identified in B. longum (e.g., Blr and BetA transporters), which actively expel conjugated bile acids from the cell.^[28]^[29]^[30] Recent studies from 2024 highlight how oxygen gradients in the gut lumen influence Bifidobacterium strain selection and colonization, with aerotolerant variants thriving in oxygenated niches near the mucosa. In 2025, genetic engineering approaches have further improved aerotolerance in probiotic strains, such as B. animalis AR668, by modulating fatty acid metabolism and oxidative enzyme expression to enhance delivery stability in oxygen-exposed products.^[31]^[23]^[32]

Mechanisms of Action

Bifidobacterium species interact with host cells through adhesion mechanisms that promote colonization of the gastrointestinal tract. Strains such as B. breve UCC2003 utilize tight adhesion (Tad) pili to bind intestinal epithelial cells, enhancing persistence in the gut environment.^[33] Mucus-binding proteins, including S-layer proteins in B. bifidum PRL2010, facilitate attachment to mucin layers, displacing potential pathogens and supporting stable colonization. Competitive exclusion is further achieved via bacteriocin production, such as bifidocin from certain Bifidobacterium strains, which inhibits the growth of Gram-negative pathogens like Salmonella.^[33] Immunomodulation by Bifidobacterium involves the induction of anti-inflammatory cytokines and regulatory immune cells. For instance, B. adolescentis ATCC15703 stimulates IL-10 production in colonic tissues and dendritic cells, dampening pro-inflammatory responses.^[34] Similarly, strains like B. longum CECT 7347 upregulate TGF-β expression, promoting the differentiation of regulatory T cells (Tregs) and fostering immune tolerance.^[34] Exopolysaccharides (EPS) produced by B. breve UCC2003 serve as anti-inflammatory agents by inhibiting dendritic cell maturation and reducing TNF-α secretion, thereby modulating innate immunity.^[34] Bifidobacterium strengthens intestinal barrier function through metabolite-mediated effects on epithelial integrity. Acetate, a key fermentation product, upregulates tight junction proteins such as ZO-1, occludin, and claudins in strains like B. infantis, reducing paracellular permeability.^[33] Acidification of the gut lumen to pH 4.5–5.5 via lactate and acetate production creates an inhospitable environment for pathogens, inhibiting their adhesion and invasion. These short-chain fatty acids, often encoded by genomic operons for carbohydrate metabolism, collectively enhance epithelial resistance to microbial translocation.^[33] Recent investigations (2023–2025) have elucidated additional mechanisms, including specialized substrate utilization for immune modulation. B. infantis M-63 efficiently metabolizes human milk oligosaccharides (HMOs) through a 43 kb gene cluster encoding glycosidases and transporters, producing indole-3-lactic acid that suppresses inflammation and supports anti-allergic immune development by enriching bifidobacteria and boosting secretory IgA.^[35] In 2025 studies, B. bifidum strains W23 and W28 desialylate mucin 13 (MUC13) via sialidase activity, enhancing transepithelial electrical resistance and barrier integrity under inflammatory conditions, which may indirectly aid pathogen exclusion. A 2025 analysis further linked Bifidobacterium abundance to a 3-fold reduction in early allergy risk, attributing this to HMO-driven microbiota shifts that favor immune tolerance.

Genomics

Genome Organization

The genomes of Bifidobacterium species are characteristically large for actinobacteria, typically ranging from 1.7 to 3.3 Mb in size, with a circular chromosome encoding approximately 1,500 to 3,000 genes.^[36] For instance, the first complete genome sequenced, that of B. longum NCC2705 in 2002, spans 2.36 Mb and contains 1,730 coding sequences.^[37] Plasmids occur at low incidence across the genus, though remnants of integrated plasmids have been observed in some strains, while CRISPR-Cas systems are prevalent as a defense mechanism against phages and foreign DNA, with 56 loci identified across 35 genomes encompassing Types I, II, and III.^[37]^[36] These genomes exhibit a GC content of 53–66%, contributing to high gene density, and are interspersed with insertion sequence (IS) elements that facilitate genomic rearrangements for adaptation.^[36]^[38] Notably, IS30 family elements are the most abundant and active, comprising a significant portion of the mobilome and enabling deletions or inversions in response to environmental pressures.^[38] Operon-like structures are common, particularly for carbohydrate metabolism, where genes for transporters, hydrolases, and regulators are clustered to coordinate the utilization of complex substrates such as oligosaccharides.^[37]^[38] As of 2025, hundreds of Bifidobacterium strains have been fully sequenced using high-throughput methods like PacBio and Illumina, enabling detailed assembly of these AT-rich genomes and revealing conserved organizational patterns.^[9] Recent pan-genome analyses, incorporating over 1,000 genomes from metagenomic studies, have further expanded understanding of genetic diversity, including new subspecies like B. longum subsp. nexus.^[39]^[40] Central metabolism genes, including those for glycolysis and the fructose-6-phosphate/phosphoketolase pathway, are often clustered in stable core regions, while variable genomic islands accommodate strain-specific adaptations.^[37] A representative example is the 43 kbp human milk oligosaccharide (HMO) utilization locus in B. longum subsp. infantis, which integrates multiple transporters and glycosyl hydrolases (e.g., fucosidases and galactosidases) for infant-specific niche exploitation.^[41]

Key Genetic Features

Bifidobacterium genomes are enriched with genes encoding glycoside hydrolases (GHs), typically numbering 200 to 300 per strain, which belong to more than 70 families specialized in glycan degradation and support their saccharolytic lifestyle in the gut.^[42] These GHs, including prominent families like GH13 (α-amylases and pullulanases), GH2 (β-galactosidases), and GH43 (xylanases), enable the breakdown of complex host-derived and dietary carbohydrates such as mucins, human milk oligosaccharides (HMOs), and plant polysaccharides. A distinctive metabolic adaptation is the bifid shunt pathway, a unique fructose-6-phosphate phosphoketolase route that yields 2.5 ATP per glucose molecule through genes encoding phosphoketolase (e.g., xpkA) and transaldolase (tal), optimizing energy extraction from hexoses and distinguishing Bifidobacterium from other gut bacteria.^[43]^[44] Key probiotic attributes are underpinned by specialized genetic loci, including adhesion operons that assemble sortase-dependent pili, such as the fim and pil gene clusters in species like B. bifidum PRL2010 and B. breve UCC2003, which promote binding to intestinal epithelial cells and extracellular matrix components.^[45]^[46] Exopolysaccharide (EPS) biosynthesis clusters, varying in size from 9 genes in B. mongoliense to 55 in B. dentium, encode glycosyltransferases and polymerases that produce surface layers enhancing biofilm formation, immune modulation, and pathogen exclusion.^[47] Horizontal gene transfer is facilitated by mobile elements like insertion sequences, transposons, and genomic islands, which integrate adaptive traits such as antibiotic resistance or novel metabolic genes, as observed in erm(X) transfer via islands among bifidobacterial strains.^[48]^[49] Pan-genome studies of Bifidobacterium reveal a compact core genome of approximately 261 orthologous groups primarily dedicated to conserved metabolic functions like the bifid shunt and basic housekeeping, while the expansive accessory genome—encompassing unique and strain-specific genes—drives niche adaptations such as specialized glycan foraging and host interactions.^[47]^[50] Metagenomic advancements in 2024, including tools like SynTracker for synteny-based strain resolution, have illuminated persistent strain tracking in the human gut, showing how accessory genes influence colonization stability and inter-individual variability.^[51]^[52] Unlike pathogenic bacteria, Bifidobacterium genomes lack pathogenicity islands, reflecting their safe commensal profile with no virulence factors like toxins or invasins. High inter-strain variability is prominent in glycan utilization loci; for example, B. longum subsp. infantis features an expanded HMO cluster spanning 43 kb with 14 dedicated genes for transport (e.g., ABC permeases) and hydrolysis (e.g., GH20, GH29, GH95), enabling superior HMO catabolism compared to the minimal single-gene setups in other B. longum subspecies.^[53]^[41]^[54]

History and Discovery

Early Observations

The genus Bifidobacterium was first identified in 1899 by French pediatrician Henri Tissier at the Pasteur Institute, who isolated Y- or V-shaped, Gram-positive rods from the feces of healthy breastfed infants. Tissier designated these organisms Bacillus bifidus based on their distinctive bifid morphology and observed their abundance in infants without gastrointestinal disorders, contrasting with their scarcity in those suffering from diarrhea, which led him to propose their therapeutic potential against such conditions.^[55]^[56] In the early 20th century, studies reinforced the association between Bifidobacterium and the gut health of breastfed infants. Researchers, including Ernst Moro, characterized the intestinal microbiota of infants around 1900, noting that bifidobacteria predominated in the stools of breastfed children, correlating with reduced susceptibility to infectious diarrhea compared to formula-fed infants. This observation underscored the bacteria's role in maintaining a beneficial microbial balance influenced by human milk components.^[57]^[55] Danish microbiologist Sigurd Orla-Jensen advanced the taxonomic framework in 1924 by establishing Bifidobacterium as a distinct genus for these bifid-shaped lactic acid producers, separating them from other bacilli while initially aligning them with lactose-fermenting bacteria. During the 1920s, Bifidobacterium was classified within the family Lactobacteriaceae due to shared metabolic traits with lactobacilli, such as homofermentative lactic acid production. By the 1950s, however, cell wall composition analysis revealed the presence of diaminopimelic acid—a marker typical of higher G+C content Gram-positive bacteria—prompting reclassification to the order Actinomycetales, reflecting their phylogenetic divergence from true lactic acid bacteria.^[8]^[58]^[59] Prior to the 1980s, experimental evidence from animal models in the 1970s demonstrated Bifidobacterium's capacity to prevent diarrhea by inhibiting pathogen adhesion and stabilizing gut microbiota, building on Tissier's early clinical insights. These findings contributed to growing interest in probiotic applications, with the first commercial Bifidobacterium product—a fermented milk—launched in Japan in 1971, followed by broader use in food products and supplements.^[55]

Research Milestones

In the 1980s, research on probiotic strains intensified, with Bifidobacterium species increasingly screened and identified for their potential health benefits in the human gut, laying the groundwork for their formal recognition as probiotics.^[60] The strain Bifidobacterium animalis subsp. lactis BB-12 was isolated and commercialized by Chr. Hansen in 1985, marking one of the earliest widespread applications of a Bifidobacterium strain in food products and supplements.^[61] During the 1990s and 2000s, genomic advancements provided deeper insights into Bifidobacterium biology. The first complete genome sequence of a Bifidobacterium strain, B. longum NCC2705, was published in 2002, revealing adaptations to the human gastrointestinal tract and over 1,700 coding sequences that underscored its metabolic versatility.^[37] In 2008, the genome of B. longum subsp. infantis ATCC 15697 was sequenced, highlighting specialized gene clusters for the utilization of human milk oligosaccharides (HMOs), which enable preferential colonization in breastfed infants.^[62] The 2010s saw metagenomic studies illuminate the ecological prominence of Bifidobacterium in the human gut microbiome. High-throughput sequencing efforts, such as those from the Human Microbiome Project, demonstrated Bifidobacterium's dominance in early-life gut communities, often comprising up to 90% of the microbiota in breastfed infants and contributing to immune maturation.^[63] In 2011, the European Food Safety Authority (EFSA) updated its Qualified Presumption of Safety (QPS) list to include all Bifidobacterium species with no safety concerns under qualified conditions, facilitating their use in food and feed applications across the EU.^[64] Recent advances in the 2020s have expanded therapeutic applications. In 2023, the Gut Microbiota for Health Foundation awarded a grant to investigate novel antimicrobial peptides produced by Bifidobacterium in the infant gut and their potential role in fortifying the mucosal barrier and inhibiting pathogens.^[65] A 2024 clinical trial demonstrated that Bifidobacterium breve 207-1 supplementation modulated the gut-brain axis by altering neurotransmitter levels and hypothalamic-pituitary-adrenal axis hormones, improving stress responses in participants.^[66] A June 2025 randomized trial evaluated a synbiotic formulation containing Bifidobacterium longum alongside prebiotics in obese individuals but found no effect on insulin sensitivity or lipids, though it explored impacts on endotoxemia markers.^[67]

Ecological Roles

Habitats and Distribution

Bifidobacterium species inhabit a variety of anaerobic environments, predominantly the gastrointestinal tracts of animals, where they play roles in microbial communities associated with nutrient fermentation. These bacteria are commonly isolated from the intestines of humans and a broad range of non-human hosts, including mammals, birds, and insects, reflecting their adaptation to oxygen-limited niches.^[6] Environmental reservoirs, such as sewage and fermented plant materials like silage, also harbor certain species, often linked to anthropogenic activities that facilitate their dissemination from animal sources.^[68] The genus displays a cosmopolitan distribution across global ecosystems, with higher prevalence in herbivores due to their fiber-rich diets that support bifidobacterial growth through substrate availability for carbohydrate degradation. For instance, Bifidobacterium boum and B. pseudolongum dominate in the rumen and hindgut of cows and other ruminants, aiding in the breakdown of complex polysaccharides.^[6] In contrast, bifidobacteria are rarely detected in aerated environments like soil, as their strict anaerobiosis limits survival outside low-oxygen settings.^[68] Specific non-human associations highlight host specialization; Bifidobacterium asteroides is found in honeybees, contributing to their gut microbiota, while B. saeculare occurs in rabbits.^[6] Metagenomic surveys of wild mammals, such as golden lion tamarins, have confirmed the presence of diverse Bifidobacterium strains in natural populations, underscoring their ecological breadth beyond domesticated animals.^[69] Distribution patterns are influenced by dietary composition and host age, with fiber-abundant diets in herbivores favoring proliferation and abundance peaking during early life stages across species before declining in adulthood.^[70] Vertical transmission from parent to offspring further shapes these patterns in social animals, enhancing persistence in specific lineages.^[71]

Association with Human Gut Microbiota

Bifidobacterium species constitute a significant but minority component of the adult human gut microbiota, typically comprising 3-6% of the total bacterial population in healthy individuals, though this can reach up to 15% in some cases with optimal dietary influences.^[1]^[72] These bacteria engage in mutualistic cross-feeding interactions with other gut microbes, such as Bacteroides and Faecalibacterium species, where Bifidobacterium produces acetate from carbohydrate fermentation, which in turn supports butyrate production by these partners, enhancing overall microbial stability and short-chain fatty acid (SCFA) yields in the colon.^[73]^[74] Such syntrophic relationships underscore Bifidobacterium's role in fostering a resilient gut ecosystem. The abundance and functionality of Bifidobacterium in the adult gut are dynamic, influenced by host factors and environmental perturbations. Levels naturally decline with advancing age, dropping from higher infant-era dominance to reduced proportions in older adults, which correlates with diminished microbial diversity and increased susceptibility to dysbiosis.^[75] Antibiotic exposure further exacerbates this decline, often causing transient but significant reductions in Bifidobacterium populations, disrupting fermentation pathways and SCFA production.^[76] Conversely, dietary modulation through prebiotics, such as inulin or fructooligosaccharides, can elevate Bifidobacterium abundance by providing selective substrates that stimulate growth and amplify SCFA output, thereby promoting microbial recovery and gut homeostasis.^[77]^[78] Bifidobacterium exhibits both cooperative and competitive interactions within the adult gut niche. It forms symbiotic partnerships with Akkermansia muciniphila, where the latter's mucin degradation releases glycans that Bifidobacterium can utilize, while acetate from Bifidobacterium supports Akkermansia's growth and reinforces the mucus layer integrity through cross-feeding dynamics.^[79]^[80] In contrast, Bifidobacterium demonstrates antagonistic effects against pathogens like Clostridioides difficile, inhibiting its sporulation, toxin production, and colonization via bacteriocin-like compounds and competition for resources, thereby mitigating infection risks in dysbiotic states.^[81]^[82] Recent metagenomic studies highlight Bifidobacterium's altered profiles in adult dysbiosis, particularly in the United States, where deficits in these bacteria are increasingly linked to widespread gut imbalances driven by modern diets and lifestyle factors, contributing to chronic inflammatory conditions.^[83] In obesity, metagenomic analyses reveal shifts characterized by lower abundance of B. longum subspecies, associating this depletion with impaired metabolic regulation and elevated adiposity, as observed in diverse adult cohorts.^[84]^[85]

Specific Role in Infants

Bifidobacterium species, particularly B. longum subsp. infantis, establish early dominance in the infant gut through vertical transmission from the mother, primarily via vaginal birth and breastfeeding, with high transmission rates observed for strains like B. bifidum and B. longum.^[86]^[87] In breastfed infants, B. longum subsp. infantis often comprises a predominant portion of the microbiota, reaching up to 90% of the fecal bacterial community due to its specialized adaptation to human milk oligosaccharides (HMOs).^[88]^[89] This colonization begins within hours of birth and peaks in the first months, supporting initial microbial stability.^[90] Human breast milk profoundly influences this colonization, as HMOs serve as selective prebiotics that Bifidobacterium species ferment preferentially, promoting their growth while inhibiting pathogens.^[91] Studies have shown that breastfeeding-associated Bifidobacterium metabolize HMOs to produce aromatic lactic acids, such as indolelactic acid, which activate aryl hydrocarbon receptor pathways in immune cells, enhancing intestinal barrier function and reducing pro-inflammatory responses in the infant gut.^[92] This immune fortification contributes to overall developmental health by modulating T-cell activity and cytokine production.^[92] In terms of developmental roles, Bifidobacterium helps prevent necrotizing enterocolitis (NEC) in preterm infants by stabilizing the gut barrier and suppressing inflammation; meta-analyses indicate significant risk reductions, with relative risks as low as 0.11 for B. lactis supplementation and 0.43 for B. breve.^[93] Post-weaning, typically around 6-12 months, the infant gut microbiota undergoes a shift, with early dominants like B. bifidum and B. longum subsp. infantis declining as B. adolescentis emerges, reflecting dietary transitions and maturation.^[94]^[95] Recent research highlights a widespread deficit of B. infantis in U.S. infants, affecting approximately 24% who lack detectable Bifidobacterium overall, with only 8% harboring B. infantis, regardless of birth mode or feeding method but exacerbated in formula-fed and C-section-born infants.^[96] This deficiency correlates with gut dysbiosis, elevated inflammation markers, and a 3-fold increased risk of immune-related conditions like allergies and eczema by age 2, contrasting with higher abundance in non-industrialized regions.^[96]^[97] Global variations are notable, as C-section births disrupt vertical transmission, leading to lower Bifidobacterium levels and heightened inflammatory profiles in affected infants.^[98]^[96]

Health Benefits and Applications

Probiotic Properties

Probiotics are defined as live microorganisms that, when administered in adequate amounts, confer a health benefit on the host, with typical effective doses ranging from 10^6 to 10^9 colony-forming units (CFU) per day.^[99]^[100] Species of the genus Bifidobacterium qualify as probiotics due to their demonstrated viability in the gastrointestinal tract, stability during storage and processing, and ability to adhere to intestinal mucosa, enabling transient colonization and potential interaction with host cells.^[12]^[101] Prominent commercial strains include Bifidobacterium animalis subsp. lactis BB-12, noted for its high tolerance to gastric acid and bile salts, allowing over 70% viability after simulated gastrointestinal passage in vitro.^[12]^[102] Another key strain, B. longum BB536, produces exopolysaccharides (EPS) that enhance its survival and contribute to gut persistence for 2-4 weeks following administration in human studies.^[103]^[104] These strains are often paired in synbiotic formulations with prebiotics such as galacto-oligosaccharides (GOS) and fructo-oligosaccharides (FOS), which selectively stimulate Bifidobacterium growth and improve colonization efficiency.^[105]^[106]^[107] Recent advancements include microencapsulation techniques, such as spray-drying with protective matrices like alginate or whey protein, which have improved Bifidobacterium delivery by maintaining viability above 80% under harsh gastric conditions in 2024 studies.^[108]^[109]^[110] In the market, numerous Bifidobacterium strains hold Generally Recognized as Safe (GRAS) status from the U.S. Food and Drug Administration (FDA), supporting their incorporation into yogurt, fermented dairy products, and dietary supplements at levels up to 10^9 CFU per serving.^[111]^[112] Emerging research and development from 2023 onward focuses on personalized Bifidobacterium strains, selected based on individual gut microbiota profiles to optimize adhesion and persistence.^[113]^[114]

Clinical Evidence and Uses

Clinical evidence supports the use of certain Bifidobacterium strains in managing gut-related disorders, particularly irritable bowel syndrome (IBS) and antibiotic-associated diarrhea (AAD). A 2023 meta-analysis of 82 randomized controlled trials involving over 10,000 patients found that probiotics, including Bifidobacterium species, provided moderate evidence for symptom relief in IBS, with significant reductions in global symptoms (standardized mean difference [SMD] -0.55, 95% CI -0.76 to -0.34). Specifically, supplementation with Bifidobacterium longum 35624 at a dose of 10^9 colony-forming units (CFU) per day for 8 weeks was associated with decreased bloating, gas, abdominal pain, and irregular bowel habits in adults with IBS. For AAD prevention, a meta-analysis of pediatric trials reported that probiotics reduced incidence by 57% (relative risk [RR] 0.43, 95% CI 0.25-0.75), with Bifidobacterium strains contributing to this effect across multiple studies. A 2025 umbrella meta-analysis confirmed probiotics reduce pediatric diarrhea incidence by ~48%.^[115] In the realm of immune modulation and allergy prevention, Bifidobacterium breve M-16V has shown promise in reducing eczema risk in infants. Randomized controlled trials have demonstrated that supplementation with this strain led to decreased eczema severity scores in affected infants. In adults, Bifidobacterium strains, such as B. longum BB536, modulate allergic responses by restoring the Th1/Th2 immune balance, as evidenced by a 2025 review of trials in allergic rhinitis where probiotic intervention lowered IgE levels and shifted cytokine profiles toward Th1 dominance.^[116] Emerging applications include metabolic and neurological benefits. For type 2 diabetes, a 2025 randomized crossover trial on Bifidobacterium animalis subsp. lactis TISTR 2591 reported improved insulin sensitivity and attenuated fasting blood glucose elevation (approximately 10% relative improvement vs. placebo) after 6 weeks of supplementation at 10^9 CFU/day.^[117] Along the gut-brain axis, B. breve MCC1274 enhanced cognitive function in mild cognitive impairment (MCI) patients in a 2022 double-blind trial, suppressing brain atrophy progression over 24 weeks and improving memory and executive function scores, potentially alleviating associated anxiety symptoms.^[118] Despite these findings, clinical outcomes are often strain-specific, with variations in efficacy depending on the Bifidobacterium isolate and dosage, as highlighted in systematic reviews emphasizing the need for targeted strain selection. Results in obesity management remain inconsistent; while some 2023-2025 trials showed modest BMI reductions (e.g., 0.5-1 kg/m²) with Bifidobacterium supplementation, others reported no significant weight loss, particularly in post-bariatric populations, underscoring the heterogeneity in metabolic responses.

Safety and Regulatory Status

Bifidobacterium species are generally recognized as safe for use in food and feed, as evidenced by their inclusion in the European Food Safety Authority's (EFSA) Qualified Presumption of Safety (QPS) list since 2011, with reaffirmation in the 2024 update based on ongoing assessments showing no new safety concerns.^[119] Genomic analyses of various strains, such as Bifidobacterium bifidum BGN4 and Bifidobacterium longum BORI, have confirmed the absence of virulence factors, supporting their low pathogenic potential.^[120] Toxicology studies in animal models demonstrate no genotoxicity in assays like micronucleus and chromosomal aberration tests, with an LD50 exceeding 10^12 colony-forming units (CFU)/kg body weight in rodents, indicating high tolerance even at extreme doses.^[121] Adverse events associated with Bifidobacterium are exceedingly rare, primarily limited to cases of bacteremia in immunocompromised individuals, with reported incidence rates below 1 per 10^8 doses administered in clinical settings.^[122] Such occurrences are typically linked to underlying health vulnerabilities rather than inherent strain pathogenicity, and no evidence of systemic toxicity or long-term harm has been observed in healthy populations.^[123] Regulatory frameworks affirm the safety of Bifidobacterium for broad applications, with the U.S. Food and Drug Administration (FDA) granting Generally Recognized as Safe (GRAS) status for various strains in food use since the 1997 proposed rule and subsequent notices starting in 1998.^[124] In the European Union, while many Bifidobacterium species fall under traditional food categories, novel strains require authorization under the Novel Foods Regulation, with strain-specific dossiers ensuring safety; for instance, Bifidobacterium animalis subsp. lactis BB-12 has been evaluated as safe for use in infant formulas, with a 2023 opinion confirming no adverse effects.^[125] As of 2025, ongoing monitoring addresses potential antibiotic resistance genes in Bifidobacterium strains, with EFSA and FDA guidelines recommending genomic screening and phenotypic testing to prevent transfer risks, particularly in probiotic formulations.^[126] For high-risk populations, such as immunocompromised patients or preterm infants, cautious use is advised, with product selection emphasizing verified strain purity and low contamination to minimize rare infectious risks.^[123]

References

[1]
Bifidobacteria and Their Role as Members of the Human Gut ... - NIH
Jun 15, 2016 · Members of the genus Bifidobacterium are among the first microbes to colonize the human gastrointestinal tract and are believed to exert positive health ...
[2]
Bifidobacteria and Their Health-Promoting Effects - PMC - NIH
Bifidobacteria are members of the intestinal microbiota of mammals and other animals, and some strains are able to exert health-promoting effects.
[3]
https://www.csbj.org/article/S2001-0370(21)00078-7/pdf
[4]
https://www.nature.com/articles/s41522-023-00467-4
[5]
Exploring the Ecology of Bifidobacteria and Their Genetic ... - NIH
The Bifidobacterium genus is one of the most abundant bacterial genera present in the human gut during the early stages of life [59,60,61] and these ...<|control11|><|separator|>
[6]
Difference in Intestinal Flora and Characteristics of Plasma ...
Bifidobacterium, Rod shape, 0.5–1.3 μm × 1.5–8 μm, No spores, no flagellum. Positive, Strict anaerobic. Prevotellaceae, Rod shape, -, No spores, no flagellum ...
[7]
Genus: Bifidobacterium - LPSN
Bifidobacterium vansinderenii · Bifidobacterium vespertilionis · Bifidobacterium xylocopae. Name: Bifidobacterium Orla-Jensen 1924 (Approved Lists 1980).
[8]
https://lpsn.dsmz.de/genus/bifidobacterium
[9]
Tracking the Taxonomy of the Genus Bifidobacterium Based ... - NIH
Jan 31, 2018 · Another accepted method that was and is still widely used in bacterial taxonomy is comparative analysis of 16S rRNA gene-based sequences (2).Missing: criteria | Show results with:criteria
[10]
Tracking the Taxonomy of the Genus Bifidobacterium Based on a ...
Jan 31, 2018 · Here, we describe a high-accuracy phylogenomic approach to assess the taxonomy of members of the genus Bifidobacterium and identify apparent ...
[11]
The Science behind the Probiotic Strain Bifidobacterium animalis ...
Bifidobacterium BB-12® (BB-12®) is a catalase-negative, rod-shaped bacterium. It was deposited in the cell culture bank of Chr. Hansen in 1983. At the time ...Missing: oxidase | Show results with:oxidase
[12]
HiBC: a publicly available collection of bacterial strains isolated from ...
May 6, 2025 · The Human intestinal Bacteria Collection (HiBC) (https://www.hibc.rwth-aachen.de) contains 340 strains representing 198 species within 29 ...
[13]
Genomic and functional diversity of cultivated Bifidobacterium from ...
Mar 15, 2024 · The genome sizes of Bifidobacterium ranged from 1.9 Mb to 2.8 Mb and the GC contents ranged from 54.66% to 63.24%. The genomes of the same ...
[14]
Carbohydrate metabolism in Bifidobacteria - PMC - NIH
As mentioned above, bifidobacteria degrade hexose sugars through a particular metabolic pathway, termed the “bifid shunt”, where the fructose-6-phosphoketolase ...Missing: equation | Show results with:equation
[15]
Bifidobacteria and Their Role as Members of the Human Gut ...
The G+C content of complete bifidobacterial genomes ranges from 59.2% (B. adolescentis) to 64.6% (B. scardovii), while the average gene number contained by a ...<|control11|><|separator|>
[16]
Human Milk Oligosaccharides: Decoding Their Structural Variability ...
All of the GH enzymes needed to effectively cleave HMOs are encoded by this gene cluster, including the GH95 family's 1,2-α-fucosidases, the GH29 family's 1,3/4 ...2. Hmos And Factors... · 3. Synthesis And Metabolism · 3.2. Metabolism<|control11|><|separator|>
[17]
Key bacterial taxa and metabolic pathways affecting gut short-chain ...
Bifidobacteria metabolise galactose to glucose via the Leloir pathway, and glucose is metabolised into acetate and lactate at a 3:2 ratio via a bifidobacteria- ...
[18]
Exploring Amino Acid Auxotrophy in Bifidobacterium bifidum PRL2010
Here, evaluation of amino acid auxotrophy and prototrophy of Bifidobacterium bifidum, with particular emphasis on B. bifidum strain PRL2010 (LMG S-28692), ...Missing: nutritional vitamins
[19]
Identifying the essential nutritional requirements of the probiotic ...
Dec 9, 2021 · Health-promoting effects of bifidobacteria include the production of antimicrobial agents and vitamins, the inhibition of adhesion of pathogens ...
[20]
Engineering bacteria to modulate host metabolism - Ciocan - 2023
May 24, 2023 · In this review, we will focus on one of these strategies that involve the use of engineered bacteria to modulate gut microbiota in the treatment of metabolic ...
[21]
Oxygen tolerance mechanism of Bifidobacterium animalis AR668 ...
Jan 1, 2025 · In addition, B. bifidum has been demonstrated to improve oxygen tolerance by upregulating the expression of cell membrane-associated proteins ...
[22]
[PDF] Activities of Oxidative Enzymes Related with Oxygen Tolerance in ...
Comparison of catalase, superoxide dismutase, NADH oxidase, and NADH peroxidase activity of 6 typical strains of bi- fidobacteria and other species of bacteria.
[23]
Bifidobacterium - an overview | ScienceDirect Topics
Optimum growth temperature ranges from 37 to 41 °C, with minimum from 25 to 28 °C and maximum from 43 to 45 °C. The optimum pH is 6.5–7.0 (no growth at 4.5 ...Missing: anaerobiosis | Show results with:anaerobiosis
[24]
Use of gases to improve survival of Bifidobacterium bifidum by ...
The large intestine is mainly anaerobic with a low oxidoreduction (redox) potential (Eh), in the range of −200 to −300 mV in the colon lumen (Wilson, 2008). ...Missing: anaerobiosis | Show results with:anaerobiosis
[25]
The first aerotolerant Bifidobacterium bifidum strain - ScienceDirect
In the present work, we discuss the molecular mechanisms underlying the aerotolerance phenotype of B. bifidum IPLA60003, which will open new strategies for the ...
[26]
(PDF) Effect of Ascorbic Acid and Cysteine Hydrochloride on Growth ...
Aug 8, 2025 · The effects of ascorbic acid and L-Cysteine Hydrochloride (Cys-HCl) on growth of Bifidobacterium bifidum BB01 and BB03 were studied by using MRS broth as the ...Missing: protectants | Show results with:protectants
[27]
[PDF] Effect of Ascorbic Acid and Cysteine Hydrochloride on Growth of ...
Jun 5, 2013 · In this study we have analyzed the effect of the addition of ascorbic acid and Cys-HCl on the growth and pH of Bifidobacterium Bifidum BB01 and ...Missing: protectants | Show results with:protectants
[28]
Bile-Inducible Efflux Transporter from Bifidobacterium longum ... - NIH
Effect of the adaptation to high bile salts concentrations on glycosidic activity, survival at low pH and cross-resistance to bile salts in Bifidobacterium.
[29]
Disruption of intestinal oxygen balance in acute colitis alters the gut ...
Jul 3, 2024 · Undoubtedly, there exists an oxygen gradient along which the diffusion of oxygen occurs from the intestinal mucosa into the lumen of the gut ...
[30]
Modulation of fatty acid metabolism improves oxygen tolerance of ...
To improve the oxygen tolerance of Bifidobacterium, 2 different strategies can be used. One strategy is homologous expression of genes that can help the strain ...
[31]
https://www.tandfonline.com/doi/full/10.1080/19490976.2024.2361493
[32]
https://www.sciencedirect.com/science/article/pii/S0022030220306378
[33]
https://doi.org/10.3390/nu15030709
[34]
Genomic Encyclopedia of Type Strains of the Genus Bifidobacterium
The approximate Bifidobacterium genome size ranged from 1.73 Mb (Bifidobacterium indicum) to 3.25 Mb (Bifidobacterium biavatii), corresponding to 1,352 and ...Missing: history | Show results with:history
[35]
The genome sequence of Bifidobacterium longum reflects its ... - PNAS
B. longum NCC2705 has a 2,256,646-bp, 60% G+C chromosomal replicon containing 4 nearly identical rrn operons, 57 tRNAs, 16 intact insertion sequence ( ...
[36]
Genome of Bifidobacteria and Carbohydrate Metabolism - PMC - NIH
The most abundant and active insertion sequences are the IS30 elements. Those elements are responsible for deletions and rearrangements into the genome and ...Genotypic Characteristics... · Carbohydrate Fermentation... · Inuline And...Missing: CRISPR operons
[37]
The genome sequence of Bifidobacterium longum subsp. infantis ...
Dec 2, 2008 · The central fermentative pathway (Bifid shunt) is denoted in black with stoichiometric coefficients representing utilization of two hexoses.Missing: equation | Show results with:equation
[38]
Genetic-Phenotype Analysis of Bifidobacterium bifidum and Its ... - NIH
Feb 22, 2023 · Forty-nine families of glycoside hydrolase were found encoded in the genome. Heat maps are shown in Figure 2.Missing: 200-500 | Show results with:200-500
[39]
Carbohydrate metabolism in Bifidobacteria - Genes & Nutrition
Feb 16, 2011 · As mentioned above, bifidobacteria degrade hexose sugars through a particular metabolic pathway, termed the “bifid shunt”, where the fructose-6- ...Missing: stoichiometry equation<|control11|><|separator|>
[40]
Transcriptional control of central carbon metabolic flux in ... - Nature
Nov 28, 2019 · Carbohydrate metabolism of bifidobacteria is performed by a rather unique pathway, the so-called phosphoketolase pathway or bifid shunt, which ...
[41]
The Sortase-Dependent Fimbriome of the Genus Bifidobacterium
Filamentous structures at the periphery of bacteria were visible in images of 256 by 256 pixels, representing a scan size of 10 μm or less. ... cells in a 100-μl ...<|control11|><|separator|>
[42]
Functional genome analysis of Bifidobacterium breve UCC2003 ...
Jun 20, 2011 · Three different gene clusters predicted to encode sortase-dependent pili are present in the genome of UCC2003, although the first gene in ...
[43]
The genus bifidobacterium: From genomics to functionality of an ...
Taxonomically classified as members of the Bifidobacteriaceae family, bifidobacteria are Gram-positive, non-motile, non-spore forming, anaerobic, saccharolytic ...
[44]
Genomic Island-Mediated Horizontal Transfer of the Erythromycin ...
Apr 28, 2022 · This is the first report to describe the transfer of the gene erm(X) via genomic islands among bifidobacteria.
[45]
Mobilome and Resistome Reconstruction from Genomes Belonging ...
Specific members of the genus Bifidobacterium are among the first colonizers of the human/animal gut, where they act as important intestinal commensals ...
[46]
Gene-trait matching across the Bifidobacterium longum pan-genome ...
Jan 8, 2018 · The objective of this study was to assess the genetic and metabolic diversity in a set of 20 B. longum strains, most of which had previously been isolated from ...
[47]
Strain tracking in complex microbiomes using synteny analysis ...
Jun 19, 2024 · We introduce SynTracker, a tool that compares microbial strains using genome synteny—the order of sequence blocks in homologous genomic regions ...
[48]
Ecology- and genome-based identification of the Bifidobacterium ...
Jan 31, 2024 · This analysis resulted in the identification of 11,024 COGs, representing the pangenome of the species. Among them, 1,068 COGs were shared ...
[49]
Genome Features of Probiotic Bifidobacteria Determining Their ...
As a result of the analysis, it was confirmed that the B. longum 379, B. bifidum 1, and B. bifidum 791 strains are not pathogenic for humans, do not contain ...
[50]
Broad Conservation of Milk Utilization Genes in Bifidobacterium ...
CGH analysis determined that HMO utilization gene regions are exclusively conserved across all B. longum subsp. infantis strains capable of growth on HMOs and ...Missing: organization | Show results with:organization
[51]
Genomic Insights into Bifidobacteria - PMC - NIH
... Bergey's Manual of Systematic Bacteriology [Bergey's Manual]), and ... Influence of nutrition on the morphology of a strain of Bifidobacterium bifidum.
[52]
Diversity, ecology and intestinal function of bifidobacteria
Aug 29, 2014 · Interestingly, the G+C content of these regions deviates from that of the genome and suggests their acquisition through a HGT mechanism [48].Taxonomic Diversity And... · The Bifidobacterium Genus · Intestinal Function
[53]
Ernst Moro (1874-1951) - A great pediatric career started at the rise ...
Aug 9, 2025 · ... infant health around 1900 when breastfeeding was not considered a matter of importance. The discovery of lactobacilli and bifidobacteria and ...Missing: Erich | Show results with:Erich
[54]
[PDF] Taxonomy of Lactobacilli and Bifidobacteria - Caister Academic Press
Jan 14, 2005 · The main discrepancy in the taxonomy of the genus. Lactobacillus is the non-correlation between phylogenetic placement and metabolic properties.
[55]
Taxonomy, Physiology, and Natural Products of Actinobacteria
Nov 25, 2015 · Bifidobacteria, first isolated by Tissier (148), are the only family of bacteria in the order Bifidobacteriales. The Bifidobacteriaceae family ...
[56]
978-1-4613-1121-8.pdf
... history, cheese still has a very vibrant image and enjoys consistent growth of about 4% p.a. ... Bifidus milk ./ ./. Bifidus milk with yoghurt flavour.
[57]
From Yaks to Yogurt: The History, Development, and Current Use of ...
Apr 28, 2015 · In the 1950s–1980s, probiotic research focused on screening potential probiotic strains from isolates in nature or from human hosts, and ...Missing: milestones | Show results with:milestones
[58]
Bifidobacterium, BB-12® | The Probiotics Institute by Chr. Hansen Inc.
Feb 25, 2020 · Bifidobacterium, BB-12® has been extensively investigated and published and has been used worldwide since 1985 with no safety concerns.Missing: commercialization 1985
[59]
The genome sequence of Bifidobacterium longum subsp. infantis ...
Dec 2, 2008 · To understand the phylogenetic distribution of the identified milk utilization gene clusters, five additional HMO-utilizing B. longum isolates ...
[60]
Metagenomics: key to human gut microbiota - PubMed
Dec 12, 2011 · Metagenomics has emerged as one of the most powerful sequence-driven approaches to study the composition and the genetic potential of this complex ecosystem.Missing: Bifidobacterium dominance 2010s
[61]
Scientific Opinion on the maintenance of the list of QPS biological ...
Dec 9, 2011 · The 2011 update reviews microorganisms previously assessed including bacteria, yeasts, filamentous fungi and viruses used for plant protection purposes.
[62]
2023 Gut Microbiota International Grant Winner | Biocodex Foundation
The objective is to study a novel group of peptides, which Bifidobacterium appear to produce in the infant gut, as well as the peptides'ability to fortify the ...
[63]
Effects of Bifidobacterium breve 207-1 on regulating ... - PubMed
Conclusion: Bifidobacterium breve 207-1 entered the organism and affected neurotransmitter and the HPA axis hormone levels via the microbiome-gut-brain axis.
[64]
Effect of Sevelamer versus Bifidobacterium longum on Insulin Sensitivity in Subjects with Obesity
**Summary of Synbiotic Information from the Study**
[65]
Bifidobacterium bifidum: A Key Member of the Early Human Gut ...
The genus Bifidobacterium belongs to the Actinobacteria phylum and this genus together with nine other genera constitute the Bifidobacteriaceae family [1].
[66]
Bifidobacteria define gut microbiome profiles of golden lion tamarin ...
Sep 21, 2023 · Here, we carried out analysis of gut metagenomic pools from 114 individuals of wild and captive GLTs and marmosets.
[67]
Gut Bifidobacteria Populations in Human Health and Aging - Frontiers
The aim of this mini-review is to describe the bifidobacteria compositional changes associated with different stages in life, highlighting their beneficial role ...
[68]
Insights into the reason of Human-Residential Bifidobacteria (HRB ...
Apr 22, 2020 · Members of Bifidobacterium are among the first microbes to colonise the human gut, and certain species are recognised as the natural resident of human gut ...
[69]
Insights into endogenous Bifidobacterium species in the human gut ...
Feb 3, 2022 · In this opinion piece, we discuss the current knowledge regarding the relevance of endogenous Bifidobacterium species associated with adulthood.Missing: prebiotics | Show results with:prebiotics
[70]
Cross-feeding interactions between human gut commensals ...
Mar 18, 2022 · The purpose of this review is to provide an appraisal of what is known about the roles of, and interactions between, Bacteroides and Bifidobacterium as key ...
[71]
Enhanced butyrate formation by cross-feeding between ...
Sep 29, 2015 · The article provides the first experimental demonstration of enhanced butyrate formation by a cross feeding mechanisms betweeen ...
[72]
Gut Bifidobacteria Populations in Human Health and Aging - PMC
Aug 19, 2016 · In adulthood, the levels of bifidobacteria are lower (2–14% relative abundance) but remain stable (Odamaki et al., 2016). Gueimonde et al. (2007) ...
[73]
Antibiotic exposure is associated with minimal gut microbiome ...
Jan 24, 2025 · We observed a short-term decrease in the relative abundance of Bifidobacterium bifidum that resolved after 1 week. Long-term, we showed lower ...
[74]
Dietary Fiber Intake and Gut Microbiota in Human Health - PMC
Dec 18, 2022 · [72] found that a supplement of inulin increased the relative abundance of Bifidobacterium from 6.69% to 15.07%. Kiewiet et al. [96] found that ...
[75]
Microbiota responses to different prebiotics are conserved within ...
Jul 29, 2022 · Prebiotics can increase production of SCFAs by the gut microbiota [30,31,32,33], and are a promising microbiota-targeting approach for ...
[76]
Proteomic study of Akkermansia muciniphila and Bifidobacterium ...
For instance, Akkermansia muciniphila (AM) is a mucin-degrading species that maintains gut health and influences the balance of the gut microbiota (Derrien et ...
[77]
Bifidobacterium breve synergizes with Akkermansia muciniphila and ...
Bifidobacterium breve synergizes with Akkermansia muciniphila and Bacteroides ovatus to antagonize Clostridioides difficile Open Access. Yanan Li,.
[78]
Bifidobacteria antagonize the life cycle of Clostridioides difficile
Dec 21, 2024 · Our results demonstrate that bifidobacteria can modify the biological cycle of C. difficile by altering the efficiency of sporulation and ...
[79]
Unveiling the inhibition mechanism of Clostridioides difficile by ...
Nov 7, 2023 · We first screened Bifidobacterium longum owing to its inhibitory effect on C. difficile growth, then observed the physiological changes ...Abstract · Introduction · Materials and methods · Results and discussion
[80]
Aging through the lens of the gut microbiome - ScienceDirect.com
A decline in beneficial bacteria (Bifidobacterium, Lactobacillus) weakens gut barrier integrity and reduces SCFA production, impacting gut and immune health.
[81]
The abundance of bifidobacterium in relation to visceral obesity and ...
Jul 29, 2022 · The abundance of Bifidobacterium significantly decreased in the visceral obesity group. Compared with the lean group, Visceral obesity group had ...Missing: metagenomic | Show results with:metagenomic
[82]
Metagenomic analysis reveals distinct changes in the gut ...
Nov 29, 2023 · At present, an increasing number of studies have shown that the gut microbiome is closely related to obesity, and gut microbes can affect human ...
[83]
Mother-to-infant vertical transmission in early life: a systematic ...
Jul 1, 2025 · This review highlights the high transmission rates of maternal Bifidobacterium strains in early-life gut seeding, particularly B. bifidum and B. longum.
[84]
Early life bifidobacterial mother–infant transmission - ASM Journals
Jun 25, 2025 · For example, Bifidobacterium dominates the infant's gut within the first 6 months, whereas Staphylococcus and Streptococcus are more common in ...
[85]
Full article: Development of gut microbiota and bifidobacterial ...
Apr 13, 2021 · Bifidobacterium, one of the first colonizers, is the dominant bacterium in breastfed infants and has important effects on the development of the ...
[86]
Infant Gut Microbiome Is Enriched with Bifidobacterium longum ssp ...
In breastfed infants, Bifidobacterium longum subspecies infantis (from here on B. infantis for short) can dominate the gut microbiome, because it is ...
[87]
Longitudinal quantification of Bifidobacterium longum subsp. infantis ...
Jan 30, 2024 · We found that BL. infantis colonization began late in the breastfeeding period both in our cohort and in other geographic locations.Results · Metagenomes With Bl... · B. Longum Subspecies...Missing: pathogenicity islands inter-
[88]
A Molecular Basis for Bifidobacterial Enrichment in the Infant ...
infantis genome contains several family 1 solute-binding proteins (SBPs; pfam01547) with predicted affinity for oligosaccharides, suggesting a link to HMO ...Missing: organization | Show results with:organization
[89]
Bifidobacterium species associated with breastfeeding produce ...
Oct 21, 2021 · Our findings reveal that breastmilk-promoted Bifidobacterium species produce aromatic lactic acids in the gut of infants and suggest that these microbial ...
[90]
Efficacy of Bifidobacterium Species in Prevention of Necrotizing ...
However, Bifidobacterium showed a significant reduction in the incidence of NEC. Bifidobacterium is the predominant fecal bacteria in breastfed infants and the ...
[91]
Cross-feeding of bifidobacteria promotes intestinal homeostasis
Jun 19, 2024 · This review discusses bifidobacterial glycan utilization strategies, focusing on the cross-feeding involved in bifidobacteria and its potential health benefits.
[92]
Age-Related Changes in the Composition of Gut Bifidobacterium ...
Jun 8, 2017 · However, the numbers of this genus substantially decrease after weaning and continue to decrease with age [33, 40, 44]. In addition, ...Missing: shift post-
[93]
Bifidobacterium deficit in United States infants drives prevalent gut ...
Jun 24, 2025 · Regardless of birth mode and/or feeding method, widespread Bifidobacterium deficit was observed, with approximately 25% of U.S. infants lacking ...
[94]
Infants in industrialized nations are losing a species of gut bacteria ...
Jun 10, 2022 · According to a study led by researchers at Stanford Medicine, the bacteria efficient at digesting breast milk are being lost as nations industrialize.Missing: 1920s | Show results with:1920s
[95]
Improving immune‐related health outcomes post‐cesarean birth ...
Sep 2, 2025 · Infants born via Cesarean section (C‐section) often have a distinct gut microbiome and higher risks of atopic and immune‐related conditions ...Missing: deficit global
[96]
The International Scientific Association for Probiotics and Prebiotics ...
Jun 10, 2014 · The FAO/WHO definition of a probiotic—“live microorganisms which when administered in adequate amounts confer a health benefit on the host”—was ...
[97]
[PDF] Guidelines for the Evaluation of Probiotics in Food
May 1, 2002 · Joint FAO/WHO Working Group Report on Drafting ... It was recognized that it is necessary to know the genus and species of the probiotic.
[98]
Understanding the probiotic health benefits of Bifidobacterium ... - NIH
In several clinical trials, the BB-12 strain has demonstrated an ability to improve symptoms in individuals experiencing a low frequency of defecation. The ...
[99]
The Science behind the Probiotic Strain Bifidobacterium animalis ...
Mar 28, 2014 · BB-12(®) exhibits excellent gastric acid and bile tolerance; it contains bile salt hydrolase, and has strong mucus adherence properties, all valuable probiotic ...
[100]
Exopolysaccharides Produced by Intestinal Bifidobacterium Strains ...
Eleven exopolysaccharides (EPS) isolated from different human intestinal Bifidobacterium strains were tested in fecal slurry batch cultures and compared ...
[101]
Capsular polysaccharide inhibits adhesion of Bifidobacterium ...
May 1, 2017 · We show that the symbiotic and probiotic B. longum 105-A contains an EPS-encoding genetic locus responsible for the production of EPS that ...
[102]
A synbiotic mixture of Bifidobacterium breve M16-V ... - NIH
Jun 28, 2024 · The beneficial effects of the synbiotic mixture of B. breve M16-V and GOS:FOS:lvPectin on lung health associated with enhanced levels of SCFAs.
[103]
A synbiotic mixture of selected oligosaccharides and bifidobacteria ...
Aug 2, 2023 · Our study demonstrates that supplementation of synbiotic mixture of scGOS/lcFOS/2'-FL in combination with a specific mix of infant-type bifidobacterial strains ...
[104]
Galacto- and Fructo-oligosaccharides Utilized for Growth by ...
B. breve and GOS/FOS are used as a synbiotic combination, and this is certainly appropriate according to the results of our study (52–54) ...
[105]
Microencapsulation of the probiotic Bifidobacterium longum by spray ...
Oct 18, 2025 · This study aimed to microencapsulate Bifidobacterium longum by spray drying, with the goal of preserving its viability and stability throughout ...
[106]
Microencapsulation Techniques for Probiotic Formulations: Current ...
Aug 30, 2025 · This review addresses a significant gap in the current literature by focussing on the encapsulation technologies developed to enhance the ...
[107]
Microencapsulation of Probiotics for Enhanced Stability and Health ...
The study showed that this technique improved the survival of Bifidobacterium longum strains while preserving the sensory properties of the product.
[108]
GRAS Notices - FDA
GRAS Notices ; 1079. Bifidobacterium longum strain KCTC 12200BP, Oct 31, 2023, FDA has no questions (in PDF)20 (240 kB) ; 1078. Bifidobacterium bifidum strain ...
[109]
[PDF] GRAS Notice No. GRN 000856 - FDA
The subject of the notice is Bifidobacterium animalis subsp. lactis strain DSM 15954 (B. animalis DSM 15954) for use as an ingredient in milk and dairy ...
[110]
Effect of Personalized Prebiotic and Probiotic Supplements on the ...
Personalized prebiotic and probiotic supplements selected according to individual intestinal microbiota and IBS subtype may alleviate the severity of IBS ...
[111]
Bacterial genomes hold clues for creating personalized probiotics
Jul 16, 2025 · The ability to predict the nutritional adaptations of Bifidobacterium strains by analyzing the distribution of hundreds of metabolic genes in thousands of ...Missing: 2023 | Show results with:2023
[112]
Update of the list of qualified presumption of safety (QPS ... - EFSA
Jul 22, 2024 · Of 83 microorganisms notified to EFSA between October 2023 and March 2024 (47 as feed additives, 25 as food enzymes or additives, 11 as novel ...Missing: Bifidobacterium 2011 reaffirmed
[113]
Safety Evaluations of Bifidobacterium bifidum BGN4 and ... - NIH
No virulence factors were found in the genomic sequences of B. bifidum BGN4 and B. longum BORI. Thus, this result shows that the genomic sequences of B ...
[114]
Safety Assessment and Probiotic Potential Comparison of ... - NIH
No acute and sub-chronic toxicity occurred in mice and rats at the maximum tested dosage of 10 g/kg BW and 1.5 g/kg BW, respectively. The lyophilized powder of ...
[115]
Probiotic treatment in an intensive care unit: a narrative review
Jun 5, 2025 · Although probiotic-associated bacteremia remains extremely rare, it is a potential risk factor, particularly in hospitalized or ...
[116]
Probiotics: Usefulness and Safety | NCCIH - NIH
The risk of sepsis is highest in infants, children, the elderly, and people with serious medical problems. One group particularly at risk for sepsis is ...
[117]
GRAS Notice Inventory
### Summary of GRAS Notices for Bifidobacterium Species (Earliest Dates)
[118]
[PDF] www.bfr.bund.de Revised Opinion on the health benefits of infant ...
Sep 14, 2023 · Also, based on the available study results, there are no indications of adverse effects from the use of Bifidobacterium lactis BB-12 in infant ...Missing: authorization | Show results with:authorization
[119]
Assessing the Antibiotic Resistance in Food Lactic Acid Bacteria ...
Jul 31, 2025 · For example, well-characterized strains from genera like Lactobacillus, Streptococcus, and Bifidobacterium have been shown to harbor resistance ...