Direct effects of alcohol on gut‐epithelial barrier: Unraveling the disruption of physical and chemical barrier of the gut‐epithelial barrier that compromises the host–microbiota interface upon alcohol exposure.

The development of alcohol‐associated diseases is multifactorial, mechanism of which involves metabolic alteration, dysregulated immune response, and a perturbed intestinal host‐environment interface. Emerging evidence has pinpointed the critical role of the intestinal host–microbiota interaction in alcohol‐induced injuries, suggesting its contribution to disease initiation and development. To maintain homeostasis in the gut, the intestinal mucosa serves as the first‐line defense against exogenous factors in the gastrointestinal tract, including dietary contents and the commensal microbiota. The gut‐epithelial barrier comprises a physical barrier lined with a single layer of intestinal epithelial cells and a chemical barrier with mucus trapping host regulatory factors and gut commensal bacteria. In this article, we review recent studies pertaining to the disrupted gut‐epithelial barrier upon alcohol exposure and examine how alcohol and its metabolism can affect the regulatory ability of intestinal epithelium. [ABSTRACT FROM AUTHOR]