Lactobacillus GG treatment ameliorates alcohol‐induced intestinal epithelial cell dysfunction

Previous studies have suggested that endotoxemia is a contributing co‐factor to alcoholic liver disease, and increased intestinal permeability is one of the mechanisms of endotoxin absorption from alcohol‐induced leaky gut. Probiotics have been shown to promote intestinal epithelial integrity and protect barrier function. However, the underlying mechanism is not fully understood. We evaluated the effect of Lactobacillus rhamnosus GG (LGG) on the alcohol‐induced barrier disruption in intestinal epithelial cell line Caco‐2 cell monolayers. Caco‐2 cells were grown for 21 days to allow them to become fully differentiated. Pretreatment with 5% alcohol induced a decrease in transepithelial resistance and an increase in FITC‐dextran permeability. Supplementation of LGG cultural supernatant (LGGs) attenuated these deleterious effects in a time dependent manner. LGGs also prevented alcohol‐induced reduction and redistribution of tight junction proteins occludin, ZO‐1 and claudin, and mucosal protecting proteins, intestinal trefoil factor and vascular endothelial growth factor. LGGs treatment attenuated an alcohol‐induced increase in reactive oxygen species and a decrease in phospho‐ERK1/2 level. LGGs attenuate the alcohol‐induced decrease in tight junctions and mucosal protecting proteins, leading to intestinal barrier dysfunction in part through MAP‐kinase dependent mechanisms.