Bifidobacterium infantis Y1
Bifidobacterium infantis Y1 is a probiotic strain that produces beneficial metabolites including short-chain fatty acids and antimicrobial compounds. It works by competing with pathogenic bacteria for intestinal adhesion sites and modulating immune responses in the gut microbiome.
Origin & History
Bifidobacterium infantis Y1 is a specific strain of Bifidobacterium longum subsp. infantis, a beneficial bacterium naturally found in the gut of breastfed infants and in breast milk. It is not extracted from plants but is produced through controlled fermentation for use as a probiotic. This strain is selected for its ability to survive harsh gastrointestinal conditions, including low pH and bile salts.
Historical & Cultural Context
There is no identified historical or traditional use for Bifidobacterium infantis Y1. Its use is modern, stemming from scientific understanding of the infant gut microbiome and natural colonization from breast milk, rather than from traditional medicine systems.
Health Benefits
["\u2022 May reduce episodes of diarrhea in infants, based on a clinical study of the related strain IM1\u00ae in infants under 3 months, though study design details are limited.", "\u2022 Helps inhibit gut pathogens like Salmonella and Cronobacter by competing for adhesion sites, as demonstrated in preclinical studies with related strains.", "\u2022 Exhibits anti-rotaviral activity, with in-vitro cell line studies showing a related strain's peptide can inhibit viral replication by 36-48%.", "\u2022 Modulates the gut environment by metabolizing human milk oligosaccharides (HMOs) into acetate and lactate, which significantly lowers stool pH, based on an RCT with the related strain EVC001.", "\u2022 Supports a healthy infant microbiome by reducing levels of potentially harmful bacteria like E. coli and Klebsiella by over 93%, according to clinical data from the related strain EVC001."]
How It Works
Bifidobacterium infantis Y1 produces short-chain fatty acids like acetate and lactate that lower intestinal pH and create an inhospitable environment for pathogens. The strain competes directly with harmful bacteria such as Salmonella and Cronobacter for binding sites on intestinal epithelial cells. It also stimulates local immune responses by interacting with toll-like receptors and promoting anti-inflammatory cytokine production.
Scientific Research
No randomized controlled trials (RCTs), meta-analyses, or PubMed PMIDs specifically for the Bifidobacterium infantis Y1 strain were identified in the available research. The current evidence is based on studies of closely related strains, such as an observational study on IM1® for infant diarrhea and a 2017 RCT on EVC001 which demonstrated successful gut colonization and pH reduction in infants.
Clinical Summary
Clinical evidence for B. infantis Y1 is limited, with most data extrapolated from the related IM1® strain. One study in infants under 3 months suggested reduced diarrheal episodes, though specific methodology and sample size details are not well-documented. In vitro studies demonstrate pathogen inhibition against Salmonella and Cronobacter through competitive adhesion mechanisms. More robust clinical trials with larger sample sizes and longer follow-up periods are needed to establish definitive therapeutic benefits.
Nutritional Profile
Bifidobacterium infantis Y1 is a probiotic microorganism, not a conventional food ingredient, and therefore does not contribute meaningful macronutrients (calories, fats, carbohydrates, or protein) in the quantities typically delivered via supplementation. Key compositional and bioactive characteristics include: (1) Cell wall components — peptidoglycan and lipoteichoic acid (LTA), which act as immunomodulatory ligands interacting with host Toll-like receptors (TLRs 2 and 4); (2) Exopolysaccharides (EPS) — produced by B. infantis strains, these complex carbohydrates serve as prebiotic-like substrates and biofilm modulators, though precise concentrations are strain- and fermentation-condition-dependent; (3) Short-chain fatty acids (SCFAs) — primarily acetate, with lesser amounts of lactate, produced as metabolic byproducts during fermentation of human milk oligosaccharides (HMOs) and lactose; acetate output in B. infantis species is estimated at 40–60 mM under in-vitro HMO fermentation conditions; (4) B-group vitamins — Bifidobacterium species broadly synthesize folate (B9) and riboflavin (B2) intracellularly, though bioavailability to the host from probiotic doses is minimal and not quantified specifically for Y1; (5) Bacteriocin-like inhibitory substances (BLIS) — produced in quantities sufficient for competitive exclusion in preclinical models, though exact concentrations are not publicly disclosed for Y1; (6) Delivery format is typically lyophilized powder at doses ranging from 10^8 to 10^10 CFU per serving, contributing negligible caloric or micronutrient load to the host diet. Bioavailability of functional effects depends on gastric acid survival, mucus layer penetration, and colonization dynamics in the infant gut.
Preparation & Dosage
No clinically studied dosages have been established specifically for Bifidobacterium infantis Y1. Related strains have been administered to infants via supplementation in formula, but specific CFU (colony-forming unit) concentrations were not detailed in the research. Consult a healthcare provider before starting any new supplement.
Synergy & Pairings
Human Milk Oligosaccharides (HMOs), Galactooligosaccharides (GOS), Fructooligosaccharides (FOS), Lactoferrin
Safety & Interactions
Bifidobacterium infantis Y1 is generally considered safe for healthy individuals as it is naturally present in infant gut microbiota. Potential side effects may include mild gastrointestinal symptoms like bloating or gas during initial colonization. Immunocompromised individuals should consult healthcare providers before use due to rare reports of bacteremia with probiotic strains. Safety during pregnancy and lactation has not been specifically established for this strain, though related Bifidobacterium species are commonly used.