Bifidobacterium longum 2b

About

What it is and where it shows up.

Bifidobacterium longum 2b is a probiotic bacterial strain belonging to the species Bifidobacterium longum, a naturally occurring anaerobic Gram-positive bacterium found in the human gastrointestinal tract. It is used as a food and supplement ingredient to support gut health, modulate immune function, and help maintain a balanced intestinal microbiota. Note: the '2b' designation appears to be a proprietary or commercial strain identifier; no strain-specific regulatory dossier for 'B. longum 2b' was located in authoritative databases, and assessments below apply to the B. longum species level.

Safety summary

The regulatory and scientific consensus.

B. longum as a species is broadly recognised as safe for the general healthy population, holding both GRAS status (FDA, multiple strain notices) and Qualified Presumption of Safety (QPS) status (EFSA, since 2007), with no established ADI. Rare cases of bacteremia have been documented in immunocompromised or severely ill patients. Serious safety concerns exist for premature or very-low-birth-weight infants (<1000 g), for whom the American Academy of Pediatrics does not endorse routine probiotic use; a fatal sepsis case linked to a B. longum subsp. infantis product has been reported.

Regulatory landscape

What food-safety regulators have decided.

Jurisdiction	Status	Note
EFSA (European Food Safety Authority) (European Union)	Approved	B. longum species granted Qualified Presumption of Safety (QPS) status by EFSA in 2007, indicating no specific safety concern at the species level. Individual strain-level characterisation—including absence of transferable antimicrobial resistance determinants—is still required before market authorisation.source
FSSAI (Food Safety and Standards Authority of India) (India)	Approved	Bifidobacterium longum is listed as a permitted probiotic organism under Schedule IV of the FSS (Health Supplements, Nutraceuticals, Food for Special Dietary Use, Food for Special Medical Purpose, Prebiotic and Probiotic Food) Regulations, 2022. Specific health benefit claims require prior approval from FSSAI; ICMR-DBT guidelines provide supplementary evaluation criteria.source
FDA (Food and Drug Administration) (United States)	Approved	Multiple B. longum strains (e.g., BORI via GRN 813, BB536 via GRN 877, CBT BG7 via GRN 1079) hold FDA GRAS status for use in dairy products and term-infant formula under 21 CFR Part 170, Subpart E. FDA raised serious safety concerns for use in pre-term infants with birth weight <1000 g, citing conflicting efficacy/safety data and at least one adverse event fatality report.source

Who should approach with care

Whose guidance would steer them away.

Infants — FDA raised serious safety concerns about probiotic use in pre-term and very-low-birth-weight infants (<1000 g), including a documented fatal sepsis case genetically linked to a B. longum subsp. infantis product; the American Academy of Pediatrics does not endorse routine probiotic use in this vulnerable population.

Other — Immunocompromised individuals and patients with severe underlying illness face a rare but documented risk of opportunistic bacteremia or infection, as Bifidobacterium species have occasionally been isolated from human clinical specimens in such patients.

Research citations

The sources behind this verdict.

1PubMed. ICMR-DBT Guidelines for Evaluation of Probiotics in Food. pmc.ncbi.nlm.nih.gov
2FDA. Regulatory Status of Live Microorganisms When Used or Intended for Use as Food Ingredients (FDA Memorandum, October 2023), 2023. fda.gov
3FDA. GRAS Notice (GRN) 1079, Bifidobacterium longum CBT BG7, 2022. fda.gov
4FDA. GRAS Notice 813 for Bifidobacterium longum BORI, 2018. fda.gov
5PubMed. Safety Evaluations of Bifidobacterium bifidum BGN4 and Bifidobacterium longum BORI, 2018. pmc.ncbi.nlm.nih.gov
6EFSA. Qualified Presumption of Safety (QPS) Assessment – EFSA, 2007. efsa.europa.eu

Independently researched6 citations