Exercise ameliorates high fat diet induced intestinal inflammation

Abstract

Oxidative stress and inflammation have emerged over the past decade as key features in chronic disease. Research has consistently supported the role of regular exercise in decreasing pro‐inflammatory responses thereby reducing the risk of developing these chronic diseases. The overall objective of this study was to identify if exercise attenuates the intestinal inflammatory response in an animal model of diet‐induced obesity. The intestine has received wide‐spread attention recently due to changes in permeability associated with high fat diets (HFD). Twenty‐four C57BL/6NTac mice (n=6/group) were randomly assigned to one of 4 groups: 1) normal (10% fat)‐sedentary; 2) normal‐exercise; 3) HFD (45% fat)‐sedentary; and 4) HFD‐exercise for 12 weeks. Animals were gradually acclimated to motorized treadmill running which culminated with the animals running 4 days/week for 40 minutes per day at 15m/min. Upon sacrifice duodenal sections were harvested and fixed in 10%NBF. The duodenums were cut longitudinally so 90+% of each duodenum could be seen and all cuts were analyzed by Dr. Stanley Lightfoot in duplicate. Results showed that HFD doubled the width of duodenal villi compared to lean animals (95μm vs. 44 μm), resulting in thinner spaces between the villi due to increased inflammatory and fat cells present in the villi. Exercise caused enhanced vessel dilation in lean animals and eliminated inflammatory and fat infiltrate in HFD animals resulting in protecting the villi from widening. These results suggest that exercise can ameliorate intestinal inflammation and could contribute to alleviating chronic diseases of intestinal origin, like obesity.