Association between gut microbiome and locomotive syndrome risk in healthy Japanese adults: A cross-sectional study

Japan faces challenges as a super-aging society, with increasing life expectancy and a prolonged unhealthy period burdening the social security system. Musculoskeletal dysfunction significantly contributes to this unhealthy period. While exercise may influence the gut microbiome, its role in age-related musculoskeletal decline remains unclear. This cross-sectional study used data from the Kanagawa "ME-BYO" Prospective Cohort Study to investigate the association between gut microbiome composition and musculoskeletal function. Participants with a 5-question Geriatric Locomotive Function Scale (GLFS-5) and gut microbiome data were included. Classification tree analysis was performed using GLFS-5 (≥ 6 indicating locomotive syndrome) as the objective variable. Explanatory variables included gut microbiome composition, age, sex, BMI, menopause status, medical history, nutritional intake, alcohol consumption, smoking history, physical activity, and sitting time. Among 568 participants (36.8% male, median age 58.5 years), three terminal nodes were identified as GLFS-5 positive, with one node involving gut microbiome composition. Participants aged ≥ 70.0 and < 78.0 years who did not consume probiotic foods and had ≥ 0.04% relative abundance of the Holdemania genus were classified as at risk for locomotive syndrome. This study suggests a potential association between gut microbiome composition and locomotive syndrome risk in older adults, particularly those with higher Holdemania abundance. However, the cross-sectional design limits causal inference. Further longitudinal and interventional research is needed to clarify the relationship between gut microbiome and musculoskeletal function, and to explore potential preventive strategies targeting the gut microbiome to reduce locomotive syndrome risk and extend healthy life expectancy.