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Safety of One of the Most Commonly Used Probiotic Strains: Systematic Review and Meta-analysis of Reported Adverse
Aneesha Kumar1, Daniel Merenstein2, Tina Tan2
1Department of Family Medicine, Georgetown University School of Medicine, 4000 Reservoir Rd. NW Building D Room 281, Washington, DC, 20007, USA. agk55@georgetown.edu.
Abstract:
Probiotics are defined as live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. Probiotics are widely used in everyday foods and supplements but very few studies have thoroughly evaluated safety. We evaluated adverse events (AEs) for one of the most widely used strains, Bifidobacterium animalis subsp. lactis (BB-12). A systematic review (SR) and meta-analysis (MA) were conducted to evaluate adverse events in human trials using BB-12. Two independent reviewers separately searched for randomized controlled trials (RCTs) using the following mesh words for inclusion: English language, double-blinded, randomized or random allocation, and placebo-controlled trial of BB-12. One hundred and eighty-one studies were identified of which 35 qualified for inclusion. All authors of the 35 studies were contacted to perform an individual patient data meta-analysis (IPDMA). Results from the MA studies showed there was no statistical difference in the rates of AE between the probiotic (15.2%) and placebo (14%) groups, odds ratio = 1.10, 95% confidence interval (0.88, 1.36), p = .40. Further, results from the IPDMA showed statistically similar unadjusted (27% vs. 25%) and adjusted rates of AE (43% vs. 41%) between BB-12 and placebo, with the relative risk of AE being 1.05, 95% confidence interval (.94, 1.15). Both meta-analysis approaches showed no difference in the rates of AE for the BB-12 and placebo groups. The data support the safety of wide usage of BB-12. However, half of the RCTs analyzed for the MA did not report AE data. This is a major limitation of published literature. This study has been registered in PROSPERO: https://www.crd.york.ac.uk/PROSPERO/view/CRD42023434556.
Insights
This study found that Bifidobacterium animalis subsp. lactis (BB-12) probiotics are safe, with no significant difference in adverse events compared to placebo. However, many trials failed to report safety data, highlighting a limitation in current research on probiotic safety.
Area of Science:
- Microbiology and Immunology
- Gastroenterology and Nutrition
Background:
- Probiotics, live microorganisms conferring health benefits, are widely consumed in foods and supplements.
- Despite widespread use, rigorous safety evaluations for many probiotic strains, including Bifidobacterium animalis subsp. lactis (BB-12), are limited.
- Adverse events (AEs) associated with probiotic consumption require thorough investigation to ensure consumer safety.
Purpose of the Study:
- To systematically evaluate adverse events (AEs) associated with Bifidobacterium animalis subsp. lactis (BB-12) in human trials.
- To determine the safety profile of BB-12 through meta-analysis (MA) and individual patient data meta-analysis (IPDMA).
Main Methods:
- A systematic review (SR) and meta-analysis (MA) were conducted, including randomized controlled trials (RCTs) of BB-12.
- Searched for double-blinded, placebo-controlled RCTs meeting specific inclusion criteria.
- Contacted authors of included studies to perform an individual patient data meta-analysis (IPDMA) for comprehensive safety assessment.
Main Results:
- Meta-analysis showed no statistical difference in AE rates between BB-12 (15.2%) and placebo (14%) groups (OR=1.10, p=0.40).
- Individual patient data meta-analysis revealed similar unadjusted (27% vs. 25%) and adjusted (43% vs. 41%) AE rates between BB-12 and placebo.
- Relative risk of AEs was not significantly different between BB-12 and placebo groups (RR=1.05).
Conclusions:
- The findings support the safety of widespread use of Bifidobacterium animalis subsp. lactis (BB-12).
- A significant limitation identified is that half of the analyzed RCTs did not report AE data, impacting the completeness of the literature.
- Further research emphasizing comprehensive AE reporting in probiotic trials is crucial for robust safety validation.
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