Abstract
Chronic obstructive pulmonary disease (COPD) is associated with reduced functional exercise capacity and increased sedentary behavior, both of which worsen prognosis. Although rehabilitation is a standard intervention, its impact on physical activity and gut microbiota remains incompletely understood. The present study enrolled 37 stable COPD patients and based on 6-min walk distance (6MWD), patients were classified into higher and lower functional exercise capacity. Physical activity was monitored using a tri-axial accelerometer, and gut microbiome composition was analyzed via 16S rRNA sequencing before and after a 12-week, home-based, rehabilitation program. At baseline, the higher functional exercise capacity group had significantly greater lower limb muscle mass, phase angle, and time spent in moderate-to-vigorous activity than the lower functional exercise capacity group. Rehabilitation did not significantly improve 6MWD or muscle mass in either group. However, sedentary time decreased significantly in the higher functional exercise capacity group, whereas it increased in the lower group. Gut microbiome profiles differed between the two groups at baseline and showed distinct changes after rehabilitation. Notably, the family level for Enterococcaceae decreased post-intervention only in the higher functional exercise capacity group. In COPD patients with higher functional exercise capacity, distinct changes in the gut microbiota were observed among participants whose sedentary time decreased.