Effects of Treadmill Exercise on Stress-Induced Gut Microbiota Dysbiosis and Brain Dysfunction

Abstract

Chronic stress disrupts the gut–brain axis, contributing to inflammation, mood disturbances, and cognitive impairment. This study aimed to examine whether treadmill exercise could alleviate restraint stress-induced depressive symptom and impaired memory function, focusing on gut microbiota composition, pro-inflammatory cytokines, step-down passive avoidance test, forced swim test. Male Sprague-Dawley rats (N = 40) were assigned to four groups: the control (n = 10), the control + treadmill exercise group (n = 10), the restraint stress group (n = 10), and the restraint stress + treadmill exercise group (n = 10). Restraint stress was applied for 2 hours daily over 30 days, and low-intensity treadmill exercise was conducted for 30 min per day, 5 days per week. Restraint stress impaired memory and increased depressive-like behavior, accompanied by elevated tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) levels in the colon and hippocampus, as well as a reduction in the abundance of Bacteroidetes phylum Bacteroides genus. Treadmill exercise reduces inflammation in the hippocampus and colon caused by restraint stress, helps restore gut microbiota balance, and improves both mood and cognitive function, supporting its role as an effective non-pharmacological intervention for stress management.