Exercise training modifies gut bacterial composition in normal and diabetic mice (LB434)

Abstract

Background: Intestinal microbiota are increasingly recognized as potential modifiers of whole‐body energy metabolism. Previous research has described changes in bacterial composition in diabetes; this study examines whether these differences can be altered with lifestyle treatment. Methods: Six‐week‐old diabetic (db/db) and control littermates (db+) were randomized into sedentary or exercise training groups for 6 weeks (n=9‐10/treatment). All animals consumed an identical, chow‐based diet. Exercise consisted of low‐intensity treadmill running (5d/week), and was ceased 48h prior to sacrifice. Cecal matter was collected from individual mice at sacrifice. Total bacterial DNA was extracted and quantified, and bacterial species were detected and profiled using qPCR and group specific primers. Genomic data is reported as the log transformed 16S rRNA copy number normalized for the amount of cecal matter analyzed. Results: Compared to db+ mice, db/db had higher Clostridium Difficile and lower Clostridium Perfringens (P蠄0.05). However, exercise training increased Clos. Perfringens levels in both db+ and db/db (P<0.001); in this way, exercise mitigated the diabetes‐induced reduction in Clos. Perfringens such that exercised db/db mice had levels (5.30 ± 0.09) similar to sedentary db+ (5.19 ± 0.06; P=0.30) and approached that of exercised db+ mice (5.49 ± 0.05; P=0.094). Exercise training independently reduced Bacteroidetes (P=0.009) and increased Clostridium Leptum (P蠄0.05) levels in both db+ and db/db animals. Finally, exercise training increased Bifidobacterium in db+ animals but not db/db mice (P<0.001 for interaction). Conclusion: Diabetes is associated with alterations in the gut bacteria profile, particularly in the Firmicutes species. Exercise training exerts independent effects on bacterial composition in both diabetic and non‐diabetic animals, and may rescue some diabetes‐associated alterations.