The impact of probiotics and synbiotics supplementation on bone health; an umbrella review of systematic reviews and meta-analysis
Mahdi Mazandarani, Narges Lashkarbolouk, Hanieh-Sadat Ejtahed, Azadeh Dehghani, Roghayeh Molani-Gol, Shirin Hasani-Ranjbar, Bagher LarijaniBackground
The effects of probiotics and synbiotics on bone health remain uncertain due to conflicting results across existing systematic reviews and meta-analyses (SRs/MAs).
Methods
PubMed/Medline, Cochrane, and Web of Science were searched through February 2025. SRs/MAs on probiotics or synbiotics for bone health were included. An umbrella review with meta-analysis of pooled effect sizes was conducted using random-effects models: Hedges’ g for bone mineral density (BMD) and muscle mass, and mean difference for muscle strength. Heterogeneity was assessed via I 2 , and AMSTAR2 rated confidence. PROSPERO ID: CRD42025636002.
Results
Our initial search identified 930 articles (488 from PubMed/MEDLINE, 260 from Web of Science, and 182 from Cochrane). After removing duplicates and screening titles, abstracts, and full texts, sixteen systematic reviews and meta-analyses were included (with 3,245 participants), and only human studies were considered for meta-analysis. Most studies investigated
Conclusion
Probiotic/synbiotic supplementation showed modest, statistically significant BMD benefits, but with substantial heterogeneity. Findings for muscle mass and strength were based on a few meta-analyses, showed high heterogeneity, and sensitivity analyses nullified significance. Current evidence does not support clinical recommendations for probiotics/synbiotics in bone health prevention.