Clostridium butyricum JJ100 and Lacticaseibacillus rhamnosus LR alleviate liver injury in mice caused by continuous high-dose-alcohol exposure by protecting the intestinal barrier, rebuilding the gut microbiota and regulating AMPK and TLR4/NF-κB signaling pathways†

Alcohol consumption poses a major global public health challenge, with excessive drinkers showing heightened susceptibility to alcoholic liver disease (ALD) – a condition with complex pathogenesis. In this study, we used male BALB/c mice with identical enterotypes to establish a sustained high-dose alcohol-induced liver injury model. The model was created through daily intragastric administration of 52% (v/v) ethanol (10 mL kg⁻¹) for four consecutive weeks, allowing us to investigate the hepatoprotective effects of probiotic supplementation with Clostridium butyricum and Lacticaseibacillus rhamnosus. Results demonstrated that probiotic treatment significantly reduced serum LPS levels while enhancing the expression of tight junction proteins (ZO-1, claudin-3, and occludin), attenuated alcohol-induced elevations in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG) and serum total cholesterol (TC) levels, and effectively mitigated both hepatic injury and dyslipidemia. Mechanistically, probiotics inhibited hepatic lipid accumulation via AMPK pathway regulation, restructured gut microbiota composition, reduced oxidative stress through gut–liver axis modulation (as evidenced by increased hepatic superoxide dismutase (SOD)/catalase (CAT) activities), strengthened intestinal barrier function, and suppressed inflammatory responses via TLR4/NF-κB pathway inhibition (with the corresponding downregulation of TNF-α, IFN-γ, IL-4, IL-6 and MPO). Notably, the probiotic agent also reversed alcohol-induced cognitive and physical impairments, restoring short-term memory and endurance in alcohol-fed mice.