# Bifidobacterium infantis ATCC 15697

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/bifidobacterium-infantis-atcc-15697
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-04-03
**Evidence Score:** 2 / 10
**Category:** Fermented/Probiotic
**Also Known As:** B. infantis ATCC 15697, Bifidobacterium longum subspecies infantis ATCC 15697, B. longum subsp. infantis ATCC 15697, ATCC 15697, Bifidobacterium infantis type strain, B. infantis type strain ATCC 15697

## Overview

Bifidobacterium infantis ATCC 15697 is a gram-positive anaerobic [probiotic](/ingredients/condition/gut-health) strain naturally dominant in the gut of breastfed infants, operating primarily through competitive exclusion of pathogens and production of short-chain fatty acids and lactic acid. It colonizes the infant intestinal mucosa by metabolizing human milk oligosaccharides (HMOs) via specialized glycosidases, lowering luminal pH and suppressing pathogenic organisms like Escherichia coli and Clostridium species.

## Health Benefits

• Enhances beneficial gut bacteria colonization - particularly effective in premature infants, with studies showing significantly higher fecal bifidobacteria levels compared to other [probiotic](/ingredients/condition/gut-health) strains (preliminary evidence from infant trials)
• Reduces harmful gut bacteria - demonstrated significant decreases in Proteobacteria and Enterobacteriaceae (0.80% vs. 2.83% in rat studies)
• Lowers endotoxin levels - animal studies showed reduced fecal and serum endotoxins through competitive exclusion of Gram-negative bacteria (preliminary evidence)
• Supports infant microbiota development - superior colonization in breast-fed infants through specialized [metabolism](/ingredients/condition/weight-management) of human milk oligosaccharides (limited human trials)
• Produces beneficial short-chain fatty acids - generates lactic, butyric, and acetic acids through HMO fermentation (mechanism-based evidence)

## Mechanism of Action

B. infantis ATCC 15697 encodes a unique HMO gene cluster including lacto-N-biose phosphorylase and sialidases that cleave fucosylated and sialylated oligosaccharides from breast milk, generating acetate and lactate that acidify the colonic environment to pH 5.0–5.5, inhibiting pathogen growth. The strain upregulates tight-junction proteins including occludin and claudin-1 in enterocytes, reinforcing epithelial barrier integrity and reducing translocation of lipopolysaccharide (LPS). Additionally, colonization modulates dendritic cell signaling via Toll-like receptor 2 (TLR2) and TLR4 pathways, promoting tolerogenic regulatory [T-cell](/ingredients/condition/immune-support) (Treg) responses and reducing [pro-inflammatory cytokine](/ingredients/condition/inflammation)s such as IL-6 and TNF-α.

## Clinical Summary

A randomized controlled trial in premature infants (n=28) by Underwood et al. demonstrated that supplementation with B. infantis ATCC 15697 plus lactoferrin produced significantly higher fecal bifidobacteria counts and lower fecal pH compared to Lactobacillus reuteri or placebo, with reductions in fecal Proteobacteria exceeding 50%. A study by Frese et al. (2017) in healthy term infants showed that a single course of B. infantis EVC001 (derived from ATCC 15697) durably colonized the infant gut for at least 30 days post-supplementation, reducing urease-producing and toxin-producing bacteria. Evidence remains preliminary, largely from small infant cohorts; adult and large-scale pediatric RCT data are limited, and long-term clinical outcomes such as reduced infection rates or allergy prevention have not been confirmed in phase III trials.

## Nutritional Profile

Bifidobacterium infantis ATCC 15697 is a probiotic microorganism, not a conventional food ingredient, so macronutrient and micronutrient content is not applicable in traditional dietary terms. However, its bioactive composition is well-characterized: The organism produces short-chain fatty acids (SCFAs) including acetate (primary metabolic output, approximately 40-60% of fermentation end products) and lactate as primary fermentation byproducts when consuming human milk oligosaccharides (HMOs). It encodes a uniquely complete HMO utilization gene cluster, enabling consumption of lacto-N-tetraose, lacto-N-neotetraose, and fucosyllactose. The strain produces folate (vitamin B9) endogenously during [metabolism](/ingredients/condition/weight-management), contributing to local gut folate availability, though quantified concentrations in situ are strain-condition dependent. Cell wall components include peptidoglycans and lipoteichoic acids, which serve as microbe-associated molecular patterns (MAMPs) interacting with host toll-like receptors (TLR-2, TLR-4). The organism produces indole-3-lactic acid (ILA) and other tryptophan metabolites that interact with aryl hydrocarbon receptors (AhR), supporting [intestinal barrier integrity](/ingredients/condition/gut-health). No dietary fiber, exogenous protein, or fat content is contributed. Typical probiotic dosing ranges from 1×10^8 to 1×10^10 CFU per serving; bioavailability of metabolic outputs is localized primarily to the colon. Protein content of the bacterial cells themselves is negligible at physiological dosing levels.

## Dosage & Preparation

Clinically studied dosages for ATCC 15697 are not well-established in human trials. Infant studies used unspecified daily oral doses administered via feeding over 2 weeks, while animal studies employed microencapsulated forms given daily for 38 days without specific CFU quantification. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

B. infantis ATCC 15697 is generally recognized as safe (GRAS) for use in healthy infants and adults, with no serious adverse events reported in published clinical trials at doses ranging from 1×10⁸ to 1.8×10¹⁰ CFU/day. Transient mild gastrointestinal symptoms including bloating and increased stool frequency have been noted in a minority of subjects. Immunocompromised individuals, including those on corticosteroids, chemotherapy, or with HIV, should use all live [probiotic](/ingredients/condition/gut-health) strains with caution due to rare documented cases of bacteremia with Bifidobacterium species. No clinically significant drug interactions have been established, though concurrent antibiotic use will substantially reduce viable cell counts and efficacy; probiotic administration should be separated from antibiotics by at least two hours.

## Scientific Research

Clinical evidence for ATCC 15697 is limited, with two small trials in premature infants showing superior colonization compared to B. animalis strains, particularly when combined with human milk. The primary evidence comes from a 38-day rat study (PMID: 24967382) demonstrating significant microbiota modulation, though no large-scale human RCTs or meta-analyses were identified.

## Historical & Cultural Context

No historical or traditional medicine use is documented for this specific ATCC 15697 strain, as it is a modern laboratory-isolated [probiotic](/ingredients/condition/gut-health) identified in the 20th century. While Bifidobacterium species naturally occur in human infant guts, there is no evidence of intentional traditional therapeutic application.

## Synergistic Combinations

Human milk oligosaccharides, Lactobacillus species, [Prebiotic](/ingredients/condition/gut-health) fibers, Galacto-oligosaccharides, Other Bifidobacterium strains

## Frequently Asked Questions

### What is Bifidobacterium infantis ATCC 15697 used for?

B. infantis ATCC 15697 is used primarily to restore and support healthy gut microbiota colonization in newborns and premature infants, where it competitively excludes harmful bacteria such as Clostridium difficile and Enterobacteriaceae. It is also studied for its role in supporting intestinal barrier function and modulating early immune programming, with commercial preparations like Evivo (EVC001) marketed specifically for infant use alongside breast milk.

### How does Bifidobacterium infantis ATCC 15697 differ from other Bifidobacterium strains?

Unlike most adult-associated Bifidobacterium species such as B. longum or B. breve, ATCC 15697 carries a complete HMO utilization gene cluster—including genes encoding lacto-N-biose phosphorylase, sialidase, and fucosidase—allowing it to exclusively metabolize the full range of human milk oligosaccharides present in breast milk. This adaptation makes it uniquely suited for the infant gut environment and confers a colonization advantage not observed in other commercially available Bifidobacterium strains.

### What is the recommended dose of Bifidobacterium infantis ATCC 15697 for infants?

Clinical trials and commercial products have used doses ranging from 1.8×10¹⁰ CFU per day in the Evivo formulation, typically administered once daily mixed with expressed breast milk for the first 30 days of life or throughout the breastfeeding period. No established universal dosing guideline from pediatric health authorities exists yet, and caregivers should consult a pediatrician before supplementing, particularly in premature or medically fragile infants.

### Is Bifidobacterium infantis ATCC 15697 safe for premature babies?

Small randomized trials, including the Underwood et al. study in very low birth weight preterm infants, reported no serious adverse events attributable to B. infantis ATCC 15697, and the strain was well tolerated alongside lactoferrin supplementation. However, regulatory agencies including the FDA have not formally approved any probiotic for necrotizing enterocolitis (NEC) prevention in premature infants, and neonatologists generally recommend individualized risk-benefit evaluation before use in infants born before 32 weeks gestation due to the theoretical risk of probiotic-derived bacteremia in this population.

### Does Bifidobacterium infantis ATCC 15697 survive without breast milk?

B. infantis ATCC 15697 is evolutionarily specialized to metabolize human milk oligosaccharides (HMOs) as its primary carbon source, and research by Frese et al. demonstrates that robust, durable colonization is significantly diminished in formula-fed infants lacking HMO substrate. In the absence of breast milk, the strain can still transiently survive on alternative fermentable substrates such as lactulose or certain plant-derived prebiotic fibers (FOS, GOS), but colonization persistence and the associated reductions in pathogenic bacteria are substantially reduced compared to breastfed conditions.

### What clinical evidence supports Bifidobacterium infantis ATCC 15697 for reducing harmful bacteria in infants?

Research demonstrates that Bifidobacterium infantis ATCC 15697 significantly reduces harmful bacteria including Proteobacteria and Enterobacteriaceae in the infant gut microbiome. In preclinical studies, this strain reduced Enterobacteriaceae levels from 2.83% to 0.80%, suggesting a meaningful shift toward a healthier bacterial balance. The strain appears particularly effective at establishing beneficial bifidobacteria colonization in premature infants compared to other probiotic alternatives.

### Who are the primary candidates that benefit most from Bifidobacterium infantis ATCC 15697 supplementation?

Premature infants represent the primary population showing significant clinical benefit, as studies indicate substantially higher fecal bifidobacteria establishment compared to full-term infants or those receiving other strains. Infants born prematurely often have delayed or compromised gut microbiome development, making this strain particularly valuable for restoring normal bacterial colonization patterns. Standard-term infants may also benefit, though the evidence is most robust for the premature population.

### How does Bifidobacterium infantis ATCC 15697 affect intestinal barrier function and endotoxin levels?

Bifidobacterium infantis ATCC 15697 demonstrates the capacity to lower endotoxin levels in the infant gut, which is significant because elevated endotoxins can compromise intestinal barrier integrity and trigger systemic inflammation. By reducing harmful gram-negative bacteria that produce endotoxins, this strain helps maintain a more stable intestinal epithelial environment. This mechanism is particularly important for vulnerable premature infants whose intestinal barriers are still developing.

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