The purpose of this research is to explore the positive effects of Lactobacillus plantarum and Lactobacillus brevis on the tissue damage and microbial community in mice challenged by Enterotoxigenic Escherichia coli (ETEC). Twenty-four mice were divided into four groups randomly: the CON group, ETEC group, LP-ETEC group and LB-ETEC group. Our results demonstrated that, compared with the ETEC group, the LP-ETEC and LB-ETEC groups experienced less weight loss and morphological damage of the jejunum. We measured proinflammatory factors of colonic tissue and found that L. plantarum and L. brevis inhibited the expression of proinflammatory factors such as IL-β, TNF-α, and IL-6 and promoted that of the tight junction protein such as claudin-1, occludin, and ZO-1. Additionally, L. plantarum and L. brevis altered the impact of ETEC on the intestinal microbial community of mice, significantly increased the abundance of probiotics such as Lactobacillus, and reduced that of pathogenic bacteria such as Proteobacteria, Clostridia, Epsilonproteobacteria, and Helicobacter. Therefore, we believe that L. plantarum and L. brevis can stabilize the intestinal microbiota and inhibit the growth of pathogenic bacteria, thus protecting mice from the gut inflammation induced by ETEC.

中文翻译：

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植物乳杆菌和短乳杆菌减轻 ETEC 在小鼠模型中引起的肠道炎症和微生物紊乱

本研究的目的是探讨植物乳杆菌和短乳杆菌对产肠毒素大肠杆菌(ETEC)攻击小鼠的组织损伤和微生物群落的积极影响。24只小鼠随机分为4组：CON组、ETEC组、LP-ETEC组和LB-ETEC组。我们的结果表明，与 ETEC 组相比，LP-ETEC 和 LB-ETEC 组的空肠体重减轻和形态损伤较少。我们测量了结肠组织的促炎因子，发现植物乳杆菌和短乳杆菌抑制了IL - β、TNF -α等促炎因子的表达。, 和 IL-6 并促进紧密连接蛋白如 claudin-1、occludin 和 ZO-1 的作用。此外，植物乳杆菌和短乳杆菌改变了 ETEC 对小鼠肠道微生物群落的影响，显着增加了乳酸杆菌等益生菌的丰度，并减少了变形杆菌、梭状芽孢杆菌、Epsilonproteobacteria和螺杆菌等病原菌的丰度。因此，我们认为植物乳杆菌和短乳杆菌可以稳定肠道微生物群并抑制病原菌的生长，从而保护小鼠免受 ETEC 诱导的肠道炎症。