Among 101 community-dwelling adults aged 65-85, specific gut bacteria showed distinct associations with movement patterns and physical capabilities. Prevotella copri correlated positively with moderate-to-vigorous physical activity and functional performance while negatively correlating with sedentary time. Roseburia species linked to superior mobility and strength measures. Conversely, potentially harmful bacteria like Bilophila wadsworthia and Eggerthella showed negative associations with activity levels and handgrip strength. This adds compelling evidence to the emerging gut-muscle axis concept, where specific microbial populations may influence sarcopenia progression and age-related physical decline. The bidirectional relationship suggests that exercise benefits may partially operate through microbiome modulation, while certain bacterial profiles might predispose individuals to maintain higher activity levels. However, the cross-sectional design prevents establishing causation—we cannot determine whether beneficial bacteria promote activity or active lifestyles cultivate healthier microbiomes. The findings are particularly relevant given accelerating sedentary behaviors in aging populations. While promising for developing microbiome-targeted interventions alongside exercise programs, longitudinal studies tracking microbiome changes with activity modifications will be essential to validate these associations and determine therapeutic potential.