Sumaya Alshatari, Malgorzata Ziarno
The pooled estimate was compatible with a possible clinical benefit but did not reach conventional statistical significance. The available evidence does not permit conclusions about long-term safety because adverse-event reporting was inconsistent, follow-up was limited, and rare or strain-specific harms could not be assessed. Larger, prospectively registered trials are required.
BACKGROUND: Evidence regarding the long-term safety and effectiveness of probiotic supplementation in at-risk populations remains limited despite increasing use among elderly, immunocompromised, and gastrointestinal patients.
METHODS: We performed a systematic review and meta-analysis of randomized and controlled studies evaluating probiotic supplementation for ≥12 weeks in at-risk populations. PubMed, Scopus, and Web of Science were searched. Pooled risk ratios (RRs) were calculated using random-effects models, and heterogeneity, sensitivity analyses, and risk of bias were assessed.
RESULTS: Five studies involving 920 participants met the inclusion criteria. Probiotic supplementation showed a non-significant trend toward clinical improvement (RR = 1.25, 95% CI: 0.99-1.56; p = 0.059) with low observed heterogeneity (I 2 = 0%). No increase in reported adverse events was observed, although safety outcomes were inconsistently reported and could not be quantitatively pooled. Sensitivity analyses supported the stability of the overall findings.
CONCLUSION: The pooled estimate was compatible with a possible clinical benefit but did not reach conventional statistical significance. The available evidence does not permit conclusions about long-term safety because adverse-event reporting was inconsistent, follow-up was limited, and rare or strain-specific harms could not be assessed. Larger, prospectively registered trials are required.