双歧杆菌拟长梗杆菌广泛存在于哺乳动物肠道中，其丰度与人类和动物的健康相关。本研究的目的是通过代谢组学分析和肝代谢组学分析，研究B. pseudolongum CCFM1253对保护机体免受脂多糖（LPS）诱导的急性肝损伤（ALI）的潜在机制。B. pseudolongum CCFM1253预防明显减弱了LPS对血清丙氨酸转氨酶（ALT）和天冬氨酸氨基转移酶（AST）活性的影响。B. pseudolongum CCFM1253预防明显减弱了ALI小鼠的炎症反应【肿瘤坏死因子（TNF）-α、白细胞介素（IL）-1β和IL-6】和升高抗氧化酶活性【总抗氧化能力（T-AOC）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和谷胱甘肽过氧化物酶（GSH-Px）】，分别通过干预Nf-kβ和Nrf2途径。B. pseudolongum CCFM1253治疗提高了ALI小鼠中Alistipes和Bifidobacterium的比例，并降低了未培养的Bacteroidales菌、Muribaculum、Parasutterella和Ruminococcaceae UCG-010的比例，这与抑制炎症反应和氧化应激强相关。非定量肝代谢组学显示，B. pseudolongum CCFM1253的肝脏保护作用可能是通过改变肝代谢产物相关的核黄素代谢、苯丙氨酸代谢、丙氨酸、柠檬酸循环（TCA循环）等来实现的。此外，核黄素暴露可以在过氧化氢处理的HepG2细胞中控制MDA、SOD和CAT的含量。B. pseudolongum CCFM1253可以有效缓解炎症反应和氧化应激，调节肠道微生物组成和肝代谢，并提高LPS处理的小鼠肝脏核黄素含量。因此，B. pseudolongum CCFM1253可能作为一种潜在的益生菌来改善宿主健康。本文章受版权保护。保留所有权利。

Bifidobacterium pseudolongum is widely exists in mammal gut and its abundance is associated with human and animal health. The purpose of this study was to investigate the potential mechanisms of B. pseudolongum CCFM1253 on protecting against lipopolysaccharide (LPS)-induced acute liver injury (ALI) by metagenomic analysis and liver metabolomic profiles.B. pseudolongum CCFM1253 preintervention remarkably attenuated the influence of LPS on serum alanine transaminase (ALT) and aspartate amino transferase (AST) activities. B. pseudolongum CCFM1253 preintervention remarkably attenuated the inflammation responses [tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6] and elevated antioxidative enzymes activities [total antioxidant capacity (T-AOC), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px)] in ALI mice by intervening the Nf-kβ and Nrf2 pathways, respectively. B. pseudolongum CCFM1253 treatment elevated the proportion of Alistipes and Bifidobacterium, and decreased the proportion of uncultured Bacteroidales bacterium, Muribaculum, Parasutterella, Ruminococcaceae UCG-010 in ALI mice, which were strongly correlated with the inhibition of inflammation responses and oxidative stress. Untargeted liver metabolomics exhibited that the hepatoprotective efficacy of B. pseudolongum CCFM1253 might be achieved by altering liver metabolites-related riboflavin metabolism, phenylalanine metabolism, alanine, citrate cycle (TCA cycle), and so on. Furthermore, riboflavin exposure could control the contents of MDA, SOD, and CAT in hydrogen peroxide-treated HepG2 cells.B. pseudolongum CCFM1253 can effectively alleviate inflammatory response and oxidative stress, and regulate the intestinal microbiota composition and liver metabolism, and elevate the liver riboflavin content in LPS-treated mice. Therefore, B. pseudolongum CCFM1253 could serves as a potential probiotic to ameliorate the host health. This article is protected by copyright. All rights reserved.This article is protected by copyright. All rights reserved.