Kefir Ameliorates Alcohol-Induced Liver Injury Through Modulating Gut Microbiota and Fecal Bile Acid Profile in Mice

ScopeAlcoholic liver disease (ALD) is the leading cause of liver-related deaths worldwide. Kefir has been studied for its properties of anti-obesity, rebuilding intestinal homeostasis, and alleviating non-alcoholic fatty liver disease. However, the possible role of kefir in the prevention or treatment of ALD has not been carefully considered. Here, it evaluated the protective effects of kefir supplementation on alcohol-induced liver injury.Methods and resultsC57BL/6J mice are fed to Lieber-DeCarli liquid diet containing alcohol to build ALD mouse model, followed by oral administration with kefir. Results indicate that kefir treatment improves liver pathological changes, decreases the expression levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and inflammatory markers, and increases antioxidant levels. Kefir supplementation also restores the intestinal barrier and altered microbial composition, indicates as increases of Blautia, Bacteroides, and Parasutterella and decreases in the Firmicutes/Bacteroidetes (F/B) ratio and populations of Psychrobacter, Bacillus, and Monoglobus. Moreover, kefir supplementation decreases the levels of total bile acids (BAs) and primary BAs and increases the secondary/primary BA ratio. Gut microbes play a key role in the conversion of primary to secondary fecal BAs.ConclusionKefir can ameliorate ALD through regulating the composition of the gut microbiota. In alcoholic liver disease (ALD) mouse models, alcohol consumption can disrupt the intestinal epithelial barrier and intestinal homeostasis, thereby resulting in hepatic inflammation and oxidative stress, and the dysbiosis of bile acid (BA) metabolism. Kefir supplementation alleviates ALD by improving the intestinal barrier, modulating the gut dysbiosis and microbiota-mediated BA metabolism, and reducing inflammation level and oxidative stress.image