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Harms Reporting in Randomized Controlled Trials of Interventions Aimed at Modifying Microbiota: A Systematic Review
Aïda Bafeta1, Mitsuki Koh2, Carolina Riveros1
1INSERM U1153 and Université Paris Descartes-Sorbonne Paris Cité, Paris, France (A.B., C.R.).
Background:
Probiotics, prebiotics, and synbiotics are used increasingly, although the safety and potential harms of these interventions are poorly understood.
Purpose:
To examine how harms-related information is reported in publications of randomized controlled trials (RCTs) of probiotics, prebiotics, and synbiotics.
Data Sources:
Cochrane Central Register of Controlled Trials, PubMed, EMBASE, and Web of Science (without language restrictions) from 1 January 2015 to 20 March 2018.
Study Selection:
RCTs assessing the safety or efficacy of at least 1 intervention involving probiotics, prebiotics, or synbiotics alone or in combination with another intervention compared with any control (such as a placebo or an antibiotic) for any clinical condition.
Data Extraction:
4 reviewers independently assessed study characteristics, the reporting of harms, and the presentation of safety results.
Data Synthesis:
Of 384 trials conducted in healthy volunteers (n = 136) or patients with any of several medical conditions (n = 248), 339 (88%) were published in specialty journals. Trials most often evaluated probiotics (n = 265 [69%]). Studies in persons with medical conditions enrolled outpatients (n = 195) and high-risk patients (n = 53). No harms-related data were reported for 106 trials (28%), safety results were not reported for 142 (37%), and the number of serious adverse events (SAEs) per study group was not given for 309 (80%). Of 242 studies mentioning harms-related results, 37% (n = 89) used only generic statements to describe AEs and 16% (n = 38) used inadequate metrics. Overall, 375 trials (98%) did not give a definition for AEs or SAEs, the number of participant withdrawals due to harms, or the number of AEs and SAEs per study group with denominators.
Limitation:
Journal publication processes may have affected the completeness of reporting; only English-language publications were examined.
Conclusion:
Harms reporting in published reports of RCTs assessing probiotics, prebiotics, and synbiotics often is lacking or inadequate. We cannot broadly conclude that these interventions are safe without reporting safety data.
Primary Funding Source:
No specific funding.
Insights
Reporting of harms in probiotic, prebiotic, and synbiotic trials is often inadequate. Comprehensive safety data is needed to conclude these interventions are safe.
Area of Science:
- Microbiology
- Gastroenterology
- Clinical Trials
Background:
- Probiotics, prebiotics, and synbiotics are increasingly used.
- The safety and potential harms of these interventions are not well understood.
Purpose of the Study:
- To evaluate how harms-related information is reported in randomized controlled trials (RCTs) of probiotics, prebiotics, and synbiotics.
- To assess the completeness and adequacy of safety reporting in these publications.
Main Methods:
- Searched multiple databases (Cochrane, PubMed, EMBASE, Web of Science) for RCTs published between January 2015 and March 2018.
- Included RCTs assessing safety or efficacy of probiotics, prebiotics, or synbiotics compared to any control.
- Four reviewers independently extracted data on study characteristics, harms reporting, and safety results.
Main Results:
- 384 RCTs were analyzed, with most evaluating probiotics (69%).
- No harms-related data was reported in 28% of trials, and safety results were missing in 37%.
- Serious adverse events (SAEs) data was absent in 80% of studies, and many reports used generic statements or inadequate metrics for adverse events (AEs).
Conclusions:
- Harms reporting in published RCTs of probiotics, prebiotics, and synbiotics is frequently lacking or insufficient.
- Inadequate reporting of safety data prevents broad conclusions about the safety of these interventions.
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