Abstract
BACKGROUND: Alcohol-associated liver disease (ALD) is characterized by gut-liver axis dysfunction and metabolic dysregulation, yet the therapeutic potential of probiotics remains underexplored. This study aimed to investigate the protective effects and mechanisms of Lacticaseibacillus paracasei 36 (LP36) against ethanol-induced ALD in mice. METHODS: Mice were pretreated with LP36 prior to ethanol exposure. Liver injury was assessed through serum ALT/AST levels, hepatic steatosis (TC/TG content), and ethanol detoxification capacity (ADH/ALDH activity). Intestinal barrier integrity was evaluated via Mucin2 and ZO-1 expression, and gut microbiota alterations were analyzed by 16S rRNA sequencing. Hepatic transcriptomics (RNA-seq) was performed to identify key regulatory pathways. RESULTS: LP36 significantly attenuated ethanol-induced liver injury, evidenced by reduced ALT/AST, improved hepatic steatosis (lower TC/TG), and enhanced ADH/ALDH activity. Mechanistically, LP36 restored intestinal barrier function (upregulated Mucin2 and ZO-1), modulated gut microbiota (suppressed Parasutterella, Romboutsia, and Christensenellaceae_R-7_group; enriched Faecalibaculum and Tuzzerella), and reduced systemic inflammation. Transcriptomics revealed LP36-mediated rescue of AMPK signaling, involving regulation of Stk11, Prkag3, lipid synthesis genes (Fasn, Acaca), and metabolic modulators (Creb3l3, G6pc3, mTOR, Rps6kb2). CONCLUSIONS: LP36 ameliorates ethanol-induced ALD by enhancing intestinal barrier integrity, reshaping gut microbiota, and restoring AMPK-dependent metabolic homeostasis. These findings highlight LP36 as a promising probiotic candidate for ALD prevention.