Intermittent fasting has been proposed to improve metabolic health, however, information on how fasting effects host-gut microbiota interactions is limited. Recent work has implied a role of the colonic mucin layer and mucin-adhered bacteria in colonic homeostasis. The colonic mucin layer is mainly composed of densely O-glycosylated proteins that protect the epithelium and mediate host-microbiota interactions. To examine the effect of intermittent fasting on host physiology and host-gut microbiota interactions, we performed a multiple diet feeding study in a high-fat diet-fed mouse model. Using correlation network analysis, we examined the effect of intermittent fasting on the associations between individual colonic mucin glycans and specific colonic mucin-adhered bacteria.
Fasting had a significant impact on the host physiology and gut microbiota of mice fed a high fat diet (HFD) compared to normal chow (NC). Specifically, intermittent fasting with HFD resulted in significantly lower body weight and higher glucose tolerance compared to mice fed the HFD with no fasting. Fasting had no significant impact on the NC groups. These physiological changes were reflected in the fecal and colonic mucin-adhered microbiota. The relative abundance of OTUs in the families Lactobacillaceae, Lachnospiraceae, Muribaculaceae, Ruminococcaceae and Parabacteroides significantly changed in response to fasting. Fasting affected the relative abundance of nine mucin glycans, including glycan Fucα1-2 Gal β1-3 GalNAc, which was significantly higher in the HFD group with fasting. Correlation network analysis was used to identify associations between specific mucin glycans and specific mucin-adhered bacteria, this revealed significant associations between the relative abundance of glycan Fucα1-2 Gal β1-3 GalNAc and OTUs in the family Lactobacillaceae. This comprehensive omics-based study is the first report on how intermittent fasting effects the associations between colonic mucin glycans and mucin-adhered microbiota.