Bifidobacterium infantis

Bifidobacterium longum subsp. infantis · B. infantis

Snapshot

Indications	Contraindications
Necrotizing enterocolitis^{1, 2} Infant diarrhea^{3, 4} Childhood respiratory illness^4–7 Irritable bowel syndrome^{8, 9} Infant gut colonization^{10, 11} Celiac disease symptoms^{12, 13}	Immune-compromised condition¹⁴ Milk allergy¹⁵

Bifidobacterium infantis (Bifidobacterium longum subsp. infantis) is an infant-gut bacterium adapted to consume human milk oligosaccharides, the carbohydrates in breast milk, and probiotic strains aim to restore that colonization¹⁶. Supplementation is used in preterm infants to reduce necrotizing enterocolitis^{1, 2}. It is also used for diarrhea and respiratory illness in young children⁴. In adults it is used for irritable bowel syndrome symptoms and persistent symptoms in celiac disease.

In irritable bowel syndrome the picture is split: one multicenter trial in women found symptom relief, but a meta-analysis found no effect from single-strain B. infantis, while composite products did help. A 2026 genomic analysis found B. infantis dominates early-life microbiota in low- and middle-income countries but is rarely detected in high-income countries, suggesting commercial strains may be mismatched; it is a genomic finding, not a trial¹⁷. Products come as powders, drops, capsules, and chewable tablets, often combined with other strains; see Form comparison.

Health Canada lists immune-compromised conditions, including long-term corticosteroid treatment, as a reason not to use licensed products¹⁴. Health Canada labels also ask for a practitioner's advice before use with fever, vomiting, bloody diarrhea, or severe abdominal pain¹⁴.

Last updated October 16, 2026. Read how we make monographs.

In the full monograph

44 sources, 32 studies

When to useThe situations practitioners use it for, each with the reason and the study behind it.
SafetyWho should avoid it, who needs extra care, and the side effects reported in studies.
InteractionsThe medicines and supplements it interacts with, the effect of each, and what labeling says to watch.
Protocol notesThe doses used in studies, how and when they were taken, and how the forms on the market compare.
How it worksWhat it is and how it works in the body, in plain terms.
Published studiesThe studies behind each use, popular claims checked against them, and trials still under way.
Word of mouthWhat patients and practitioners report online, kept separate from the clinical evidence.
Clinical perspectiveA closing read of where the evidence is solid, where it is thin, and what has not been studied.

Snapshot

In the full monograph

Sources