THE IMPACT OF DIET AND FASTING PROTOCOLS ON INTESTINAL ARCHITECTURE AND IMMUNE PARAMETERS

Abstract

High fiber/plant-based diet and fasting and timed feeding protocols under a high-fat diet change the gut microbiota, the histological structure, and the immune parameters of the intestine. The purpose of this study was to assess the influence of different dietary interventions, including a high-fiber/plant-based or a high-fat diet, and several timfeeding protocols, on the intestinal crypt and villus morphology, the number of intestinal goblet cells (GC), and the changes in inflammatory parameters. Healthy C57BL/6 male mice were fed a high fat (HF) diet for 6 weeks, and then randomly divided to follow 1) continual-ad libitum high-fat diet (HFD), 2) a chow diet (SW-C), 3) purified high-fiber diet (Daniel Fast, DF), 4) calorie restricted HF diet , 5) a HF diet with time-restricted feeding (TRF) or 6) a HF diet with alternate-day fasting (ADF). The histological change of villi and crypt was assessed by hematoxylin & eosin, and Periodic Acid-Schiff (PAS)-Alcian Blue (AB) was used to assess the change in GCs number. We also examined changes to the immune parameters in intestinal tissues by RT-PCR. Morphologically, HF resulted in a significant reduction in crypt depth of the small intestine and colon, while DF had a slightly longer crypt depth. DF also significantly increased the number of GCs in the crypt region of the colon. The number of GCs was also increased in colon-villi of DF group.The expression level of RORγt was induced in all high fat diet groups while the DF group had a lower level of RORγt expression. DF also had a high level of Foxp3+ expression. These data suggest that the compositions of diet is what have the significant effect on intestinal architecture and immunity rather than fasting and different timed feeding protocols.