Six Weeks of Moderate-Intensity Treadmill Exercise Improves Intestinal Barrier and Intestinal Inflammation in Parkinson's Disease Mice.

More than 80% of patients with Parkinson's disease (PD) exhibit severe gastrointestinal symptoms, which seriously affect life quality of life. Several large-scale epidemiological studies have confirmed that exercise can improve motor symptoms of PD patients, but the influence on gastrointestinal symptoms has not been reported. To clarify whether exercise can enhance intestinal barrier and ameliorate intestinal inflammation in PD mice, we examined whether moderate-intensity treadmill exercise for 6 weeks could alleviate gastrointestinal symptoms in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced subacute PD mice. Our results demonstrated that 6 weeks moderate-intensity treadmill exercise enhanced the expression of Muc-2 and tight junction proteins, while reducing the expression of cytokines and chemokines, in the distal colon. Moreover, 6 weeks of treadmill exercise reduced the concentrations of short-chain fatty acids (SCFAs) and the expression of G protein-coupled receptor 43 (GPR43) to maintain the intestinal barrier and alleviate intestinal inflammation. Further data showed that 6 weeks of moderate-intensity treadmill exercise enhanced insulin-like growth factor 1 (IGF-1) expression and activated the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) signaling pathway. Taken as a whole, these results revealed that 6 weeks of moderate-intensity treadmill exercise enhanced intestinal barrier function, reduced intestinal inflammation and corrected abnormal concentrations of SCFAs by activating IGF-1/PI3K/Akt pathway in MPTP-induced subacute PD mice.