Impact of peripheral circadian misalignment and alcohol on the resiliency of intestinal barrier and microbiota.

Circadian organization is involved in many gastrointestinal tract (GIT) functions such as the maintenance of intestinal barrier integrity. There is compelling evidence that perturbation of the circadian clock decreases intestinal epithelial cells' resiliency to alcohol-induced injury. One of the most common causes of circadian misalignment is wrong-time eating (largest meal at dinner) in modern societies. Yet, few studies have examined the importance of peripheral circadian rhythms of the GIT to alcohol consumption. Eating patterns during physiologic rest time, defined as wrong-time eating (WTE), misalign the peripheral circadian clock of the GIT and the body's central clock. This study aims to fill this knowledge gap by testing the hypothesis that: (1) WTE worsens alcohol-induced disruption of intestinal barrier integrity and (2) decreased intestinal barrier resiliency to alcohol effects by WTE-disrupted circadian is, at least in part, due to microbiota dysbiosis. Alcohol (20% v/v) and a restricted timed-food paradigm were administered to PERIOD2 luciferase (PER2:LUC) reporter BL/6 mice for 10 weeks. Intestinal barrier integrity, intestinal (stool) microbiota, and microbial metabolites (cecal-derived) were examined. Peripheral circadian misalignment exacerbated alcohol-induced disruption of intestinal barrier integrity (tight junctional proteins) leading to increased intestinal permeability (p < 0.05). In addition, alcohol consumption changed the intestinal microbiota community, decreasing beneficial short-chain fatty acid-producing taxa. Further, we recapitulated the in vivo phenotype in a colonic organoid model and demonstrated that microbial metabolites from circadian-disrupted, alcohol-fed mice mediate decreased resiliency of intestinal epithelial barrier function. Peripheral circadian misalignment through food timing decreases the resiliency of the intestinal barrier to alcohol-induced injury and this effect is mediated through dysbiotic microbiota metabolites.