NCT00611299: BB-12 and CRL-431 probiotics: dose-response study

This identifier concerns dose-response testing of the probiotic strains BB-12 and CRL-431 in healthy young adults. In the matched original report, 75 people enrolled and 71 completed a randomized, double-blind comparison of placebo and four probiotic doses, with a three-week intervention. 1 2 3

Recovery of BB-12 in fecal samples increased with dose; CRL-431 was not recovered by the study's testing approach. Higher doses were associated with looser stools, while the report did not show an overall dose-response improvement in blood lipids. The published title uses “CRL-341,” whereas the study text and registration identify CRL-431; that naming discrepancy should not be silently rewritten as a different strain. 2

These findings concern bacterial recovery, tolerability, and physiological measures in healthy adults. They do not establish treatment efficacy for chronic diarrhea, inflammatory bowel disease, or childhood infection prevention. 2

Sources

1. ClinicalTrials.gov — ClinicalTrials.gov — NCT00611299. Original study registration: sponsor, design, population, endpoints and dated history.Original study registration · Original record checked against the registry API. Checked 2026-10-10. Registration and current registry fields do not by themselves establish efficacy. Historical details in the article retain their stated date. Supplied note: ClinicalTrials.gov — NCT00611299. Original study registration: sponsor, design, population, endpoints and dated history.

2. PubMed — Larsen et al., original dose-response reportResearch publication · Publication abstract read via Europe PMC; identifier and title cross-checked. Checked 2026-10-10. Full paper was not independently re-read for this update; abstract details should not be extended beyond what it reports.

3. Original immune-response report — Original immune-response reportCited supporting source · Link and description preserved from supplied research. Checked in supplied research dated 2026-10-10. Source description comes from supplied research; underlying page was not independently re-read for this update.