Disease-Associated and Shared Gut Microbes of Sarcopenia and Osteoporosis: A Systematic Review and Meta-Analys

Age-related declines in muscle and bone mass increase the risk of sarcopenia and osteoporosis. Both conditions contribute to morbidity and mortality in older adults and frequently coexist as osteosarcopenia. Gut microbiota play a crucial role in maintaining muscle and bone homeostasis, and dysbiosis may accelerate the onset and progression of these conditions. We therefore performed a systematic review and meta-analysis of observational studies published up to May 6, 2025. We identified 45 eligible studies including 6,751 participants. Patients with sarcopenia showed significant reductions in α-diversity indices compared with controls, including Chao1 (SMD=-0.28, 95% CI=-0.44, -0.11), observed species (SMD=-0.52, 95% CI=-0.79, -0.25), and ACE (SMD=-0.24, 95% CI=-0.48, -0.01), whereas patients with osteoporosis exhibited no significant differences. Distinct clustering of β-diversity was observed in twelve of eighteen sarcopenia studies (66.7%) and twelve of twenty-one osteoporosis studies (57.1%). This suggests that microbial community structures are altered in both conditions. Moreover, sarcopenia and osteoporosis shared consistent microbial alterations, with enrichment of the genus Eggerthella and depletion of the family Lachnospiraceae and the genus Blautia. A qualitative summary of functional pathway analyses suggests potential enrichment of purine, pyrimidine, cysteine and methionine metabolism, implying common metabolic disruptions. These findings highlight overlapping microbial signatures in sarcopenia and osteoporosis and support a role for gut dysbiosis in musculoskeletal decline. They also provide mechanistic clues that may help guide future preventive and therapeutic strategies for osteosarcopenia.