ACCELEROMETER-BASED SEDENTARY BEHAVIOUR AND PHYSICAL ACTIVITY ARE ASSOCIATED WITH THE GUT MICROBIOTA IN 8507 INDIVIDUALS FROM THE POPULATION-BASED SCAPIS

ABSTRACT Objective Population-based studies investigating the relationship between physical activity and the gut microbiota composition have mainly relied on self-reported activity, potentially influenced by reporting bias. Here, we investigated associations of accelerometer-based sedentary behaviour and physical activity with the gut microbiota composition and functional profile in the large Swedish CArdioPulmonary bioImage Study. Methods In 8507 participants aged 50-65, the proportion of time in sedentary (SED), moderate-intensity (MPA), and vigorous-intensity (VPA) physical activity were estimated with hip-worn accelerometer. The gut microbiota was profiled using shotgun metagenomics of fecal samples. We fitted multivariable regression models, and adjusted for sociodemographic, lifestyle, and technical covariates while also accounting for multiple testing. Results Overall, SED and MPA were associated with microbiota species in opposite directions. For example, the strongest positive regression coefficient for MPA and the strongest negative for SED were with Prevotella copri , a plant-polysaccharide-degrading bacteria. Species associated with VPA aligned with the MPA associations, although with clear discrepancies. For instance, Phocaeicola vulgatus was negatively associated with MPA, while the association with VPA was non-significant and in the positive direction. Additional adjustment for dietary variables or adiposity attenuated some of the associations. For the functional profile, MPA and VPA were generally associated with lower capacity for amino acid degradation. Conclusion Our findings suggest that sedentary behaviour and physical activity are associated with a similar set of gut microbiota species and functions, but in opposite directions. Furthermore, the intensity of physical activity may have specific effects on certain species of the gut microbiota.