Impact of probiotic, prebiotic, and synbiotic supplementation on the gut microbiome in older adults with sarcopenia, obesity, and sarcopenic obesity

Gut microbiome plays an important role in several metabolic, immune, and inflammatory pathways; however, there is limited evidence for its role in body composition and musculoskeletal health. Sarcopenia, defined as a loss of skeletal muscle mass and function, and obesity, can co-exist in a condition known as sarcopenic obesity. This condition is highly prevalent among older adults, hence increasing the risk of negative health implications such as metabolic dysfunction, chronic inflammation, reduced physical performance, and poor quality of life. These age-related conditions are closely associated with alterations to the gut microbiome, including microbial profiles and a reduction in beneficial metabolites such as short-chain fatty acids (SCFAs). Probiotic, prebiotic, and synbiotic interventions are therefore emerging as promising strategies to improve the gut microbiome by enhancing microbial diversity and restoring microbial communities. This review utilizes current evidence on the impact of these interventions on gut microbiota composition, inflammatory and metabolic biomarkers, body composition, and functional outcomes in older adults with sarcopenia, obesity, and sarcopenic obesity. Probiotics, containing live beneficial microorganisms, have shown potential in enhancing SCFA production, reducing inflammation, and improving insulin sensitivity. Prebiotics are non-digestible fibers that selectively activate the growth of beneficial gut bacteria, further supporting gut health by proliferating the growth of SCFA-producing bacteria. Synbiotics, a combination of probiotics and prebiotics, provide a synergistic approach to gut health, accounting for the microbial composition and functional capability. Recent studies have demonstrated that probiotics, prebiotics, and synbiotics may reduce inflammation and improve muscle mass and strength among older adults with sarcopenia, obesity, and sarcopenic obesity. These interventions have the potential in mitigating obesity-related metabolic dysfunction and inflammation, particularly in individuals with sarcopenic obesity. Although, preclinical studies in mice exhibit beneficial effects, clinical studies in older adults remain limited, with heterogeneity of study design, intervention types, and outcome measures. This review highlights the need for robust, well-designed clinical trials to understand the mechanistic and molecular pathways through which probiotic, prebiotic, and synbiotic supplementation may modulate the gut microbiome and improve musculoskeletal health among older adults. These interventions may provide innovative, non-invasive therapeutic strategies for managing sarcopenia, obesity, and sarcopenic obesity, ultimately contributing to healthier aging and improved quality of life of older adults. This review also underscores the potential of microbiome-targeted interventions for aging populations, highlighting the need for further research.