Bifidobacterium longum

About

What it is and where it shows up.

Bifidobacterium longum is a gram-positive, anaerobic probiotic bacterium that is a natural constituent of the human gut microbiota and is commonly isolated from the intestines of healthy infants and adults. It is used as a live microbial ingredient in fermented dairy products, infant formula, and dietary supplements to support gut health and immune function.

Safety summary

The regulatory and scientific consensus.

B. longum has been granted GRAS (Generally Recognized as Safe) status by the US FDA for multiple strains and Qualified Presumption of Safety (QPS) status by EFSA; the scientific consensus is that most Bifidobacterium species are nonpathogenic and pose no specific safety concerns to healthy populations. Rare cases of bacteremia or sepsis have been documented almost exclusively in immunocompromised patients or those with severe underlying disease. Extremely preterm infants represent a vulnerable population, as the FDA has received at least one adverse event report of sepsis fatality in a preterm neonate associated with a B. longum subsp. infantis product; no numerical ADI in mg/kg body weight has been established.

Regulatory landscape

What food-safety regulators have decided.

Jurisdiction	Status	Note
Health Canada (Canada)	Approved	Bifidobacterium longum is accepted for use as a microorganism in food products in Canada. Specific health claims may be made when the level of use meets the minimum viable cell count threshold prescribed by Health Canada guidance.source
EFSA (European Food Safety Authority) (European Union)	Approved	Bifidobacterium longum (including subspecies infantis) was granted Qualified Presumption of Safety (QPS) status by EFSA in 2007 and has been re-confirmed through multiple updates, most recently through March 2025 (BIOHAZ Panel Statement). QPS qualification requires absence of acquired transferable resistance genes to clinically relevant antimicrobials. Applicable to food, feed additives, and food enzymes; human probiotics as health claims fall under Regulation (EC) No 1924/2006.source
FDA (Food and Drug Administration) (United States)	Approved	Multiple strains hold GRAS status through scientific procedures under 21 CFR §170.30(a) and (b), including B. longum BB536 (GRN 268, GRN 877), B. longum BORI (GRN 813), and B. longum CBT BG7 (GRN 1079). Permitted in conventional foods and non-exempt term infant formulas. FDA does not endorse routine use of live microorganisms in preterm infants with birth weight <1000 g.source

Who should approach with care

Whose guidance would steer them away.

Infants — FDA has documented at least one adverse event fatality involving sepsis in an extremely preterm infant associated with a B. longum subsp. infantis product, and the American Academy of Pediatrics does not endorse routine use of live microorganisms in preterm infants, particularly those with birth weight below 1000 grams.

Other — Rare bacteremia and sepsis cases involving B. longum have been reported almost exclusively in immunocompromised patients or those with severe underlying illnesses such as malignancy or organ transplantation; such individuals should seek medical guidance before consuming probiotic products containing live B. longum.

Research citations

The sources behind this verdict.

1EFSA. Update of the list of QPS-recommended microbiological agents intentionally added to food or feed as notified to EFSA 22 (until March 2025), 2025. pmc.ncbi.nlm.nih.gov
2FDA. Regulatory status of live microorganisms when used or intended for use as human food or dietary supplements, 2023. fda.gov
3EFSA. Update of the list of QPS-recommended biological agents intentionally added to food or feed as notified to EFSA (2019), 2020. pmc.ncbi.nlm.nih.gov
4FDA. GRAS Notice 877: Bifidobacterium longum BB536, 2019. fda.gov
5FDA. GRAS Notice 813: Bifidobacterium longum BORI, 2018. fda.gov
6PubMed. Safety Evaluations of Bifidobacterium bifidum BGN4 and Bifidobacterium longum BORI, 2018. pubmed.ncbi.nlm.nih.gov

Independently researched6 citations