酒精性肝病（ALD）是由过量饮酒引起的慢性肝损伤，可能受到肠肝轴功能障碍的影响。肠道微生物群在 ALD 的发生和进展中发挥着至关重要的作用。鉴于肠肝轴功能障碍在 ALD 中的作用，针对肠道微生物群调节的策略引起了治疗干预的兴趣。长双歧杆菌亚种longum BL21 在减轻高脂饮食引起的肥胖和 2 型糖尿病模型中的肠道微生物群紊乱和代谢调节方面显示出了前景。因此，本研究旨在评估BL21对ALD小鼠的治疗效果，并探讨肠道菌群介导BL21改善ALD的潜在机制。将30只小鼠随机分为三组（n = 10只小鼠/组）：健康对照(CTL)组、ALD组和BL21组。每组均喂食 Lieber-DeCarli 流质饮食（ALD

Alcoholic liver disease (ALD) is a chronic liver injury caused by excessive alcohol consumption, could be impacted by gut-liver axis dysfunction. The gut microbiota plays a crucial role in the development and progression of ALD. Given the role of gut-liver axis dysfunction in ALD, strategies targeting gut microbiota modulation have gained interest for therapeutic interventions. Bifidobacterium longum subsp. longum BL21 has shown promise in alleviating gut microbiota disturbances and metabolic regulation in high-fat diet-induced obesity and type 2 diabetes mellitus models. Thus, this study aimed to evaluate the therapeutic effect of BL21 on ALD mice and explore the potential mechanism by which the gut microbiota mediates the amelioration of ALD by BL21.Thirty mice were randomly assigned to three groups (n = 10 mice/group): a healthy control (CTL) group, an ALD group, and a BL21 group. Each group was fed a Lieber-DeCarli liquid diet with (ALD & BL21) or without alcohol (CTL). The intervention period lasted 6 weeks, after which the effects of BL21 intervention (intragastric administration of 1 billion CFU of BL21 daily) on serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, hepatic oxidative stress, serum inflammatory cytokine levels, and gut microbiota composition in ALD mice were investigated.Dietary BL21 reduced the ethanol-induced abnormal elevation of serum AST and ALT levels in ALD mice (p < 0.001 for both). BL21 treatment significantly attenuated alcohol-induced hepatic oxidative stress by decreasing malondialdehyde concentration and increasing superoxide dismutase, catalase, and glutathione concentrations in the livers of ALD mice. In addition, the serum levels of tumor necrosis factor-alpha, interleukin-1 beta (IL-1β), and IL-6 were significantly lower (p < 0.001 for both), while that of IL-10 was significantly higher (p < 0.05), in the BL21 group than in the ALD group. Intestinal microbiota analysis showed an increased relative abundance of Escherichia/Shigella, Enterococcus, and Alistipes in the ALD group compared with the CTL group. BL21 intervention increased the relative abundance of Bifidobacterium and Akkermansia compared with the ALD group.Dietary BL21 ameliorates ALD via enhancement of the hepatic antioxidant capacity and modulation of the gut microbiota and may therefore be a promising strategy to prevent or treat ALD.© The Author(s) 2023. Published by Oxford University Press on behalf of Applied Microbiology International.