Lacticaseibacillus rhamnosus LRa05 alleviated liver injury in mice with alcoholic fatty liver disease by improving intestinal permeability and balancing gut microbiota.

This study investigated the effect of Lacticaseibacillus rhamnosus LRa05 on alcoholic fatty liver disease (ALD) and its mechanism for liver protection. Mice were randomly divided into three groups: a control (CLT) group, an ALD group, and a LRa05 intervention group. The ALD mouse model was established by Lieber-DeCarli chronic alcohol feeding. Tissues staining, enzyme-linked immunosorbent assay (ELISA) was performed to detect changes in histopathology and inflammatory cytokines, respectively. Moreover, intestinal permeability was evaluated by the level of dextran-fluorescein isothiocyanate (Dx-FITC) in serum and tight junction protein in the colon. Changes in the composition of the gut microbiota were assessed by 16S rRNA sequencing. Alcohol consumption induced liver damage in mice with significantly increased levels of triglycerides (TG), aspartate aminotransferase (AST), alanine transaminase (ALT), and inflammatory cytokines. Moreover, alcohol further induced the increase of intestinal permeability and disruption of gut microbiota in mice, with an increase in the relative abundance of potentially pathogenic bacteria Enterococcus, Parabacteroides, and Alistipes. LRa05 intervention significantly attenuated alcohol-induced liver injury by reducing the contents of TG, ALT, and AST, and suppressing the inflammatory responses. Meanwhile, by stimulating the expression of ZO-1, Occludin, and Claudin in the colon tissue, LRa05 additionally strengthened the intestine barrier function. Furthermore, gut microbiota analysis suggested that LRa05 partially ameliorated gut microbiota disorders in ALD mice and up-regulated the abundance of Desulfovibrio and Akkermansia, which were negatively correlated with the indicators of ALD progression. The reconstructive effects of LRa05 on the gut microbiota might be related to the efficacy of LRa05 in improving gut permeability and further protecting against ALD.