Lactobacillus Acidophilus Protects against alcohol-associated Liver Disease in Mice Via Gut Microbiota Modulation and Alleviation of Inflammation and Oxidative Stress.

Alcohol-associated liver disease (ALD) is a severe liver disease caused by excessive alcohol consumption. ALD remains a clinical challenge with limited therapeutic options. Following 5-day pretreatment with Lactobacillus acidophilus (Lac), mice were administered ethanol by gavage to induce ALD. Tissues were collected and analyzed for serum markers, hepatic pathology/inflammation/oxidative stress, ileal morphology/tight junctions, and cecal microbiota via 16 S rRNA gene sequencing. The fecal microbiota transplantation (FMT) experiment was performed, and tissues were then collected and analyzed as above. Moreover, the anti-inflammatory and antioxidant properties of Lac-derived particulate matter (pLac) were evaluated on RAW264.7 macrophages in vitro. Lac administration improved gut microbiota composition, enhanced intestinal barrier integrity and reduced lipopolysaccharide (LPS) translocation to the liver, thereby inhibiting the toll-like receptor 4 (TLR4)/ nuclear factor kappa B (NF-κB) pro-inflammatory pathway and activating the adenosine monophosphate activated protein kinase (AMPK)- peroxisome proliferator activated receptor α (PPARα) signaling axis. This led to significant attenuation of hepatic inflammation, oxidative stress and steatosis. The FMT experiments further validated that Lac-mediated protection is dependent on gut microbiota modulation. In vitro studies revealed that pLac exhibit direct anti-inflammatory and antioxidant properties. These findings elucidate the mechanistic basis for Lac in alleviating acute ALD, positioning it as a promising treatment or dietary intervention to enhance clinical management.