Lactobacillus probiotics exert their effects in a strain-specific and metabolite-specific manner. This study aims to identify lactobacilli that can effectively enhance the intestinal barrier function both in vitro and in vivo and to investigate the underlying metabolite and molecular mechanisms involved. Nine Lactobacillus isolates were evaluated for their ability to enhance the IPEC-J2 cellular barrier function and for their anti-inflammatory and anti-apoptotic effects in IPEC-J2 cells after an enterotoxigenic Escherichia coli challenge. Of the nine isolates, L. plantarum T10 demonstrated significant advantages in enhancing the cellular barrier function and displayed anti-inflammatory and anti-apoptotic activities in vitro. The bioactivities of L. plantarum T10 were primarily attributed to the production of exopolysaccharides, which exerted their effects through the TLR-mediated p38 MAPK pathway in ETEC-challenged IPEC-J2 cells. Furthermore, the production of EPS by L. plantarum T10 led to the alleviation of dextran sulfate sodium-induced colitis by reducing intestinal damage and enhancing the intestinal barrier function in mice. The EPS is classified as a heteropolysaccharide with an average molecular weight of 23.0 kDa. It is primarily composed of mannose, glucose, and ribose. These findings have practical implications for the targeted screening of lactobacilli used in the production of probiotics and postbiotics with strain-specific features of exopolysaccharides.

中文翻译：

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植物乳杆菌 T10 产生的胞外多糖负责增强体外和体内肠道屏障功能的益生菌活性

乳酸菌益生菌以菌株特异性和代谢物特异性的方式发挥作用。本研究旨在鉴定能够在体外和体内有效增强肠道屏障功能的乳酸杆菌，并研究其潜在的代谢物和分子机制。评估了九种乳杆菌分离株增强 IPEC-J2 细胞屏障功能的能力，以及在产肠毒素大肠杆菌攻击后对 IPEC-J2 细胞的抗炎和抗凋亡作用。在这九个分离株中，植物乳杆菌T10在增强细胞屏障功能方面表现出显着的优势，并在体外表现出抗炎和抗凋亡活性。植物乳杆菌T10的生物活性主要归因于胞外多糖的产生，胞外多糖通过 TLR 介导的 p38 MAPK 途径在 ETEC 攻击的 IPEC-J2 细胞中发挥作用。此外，植物乳杆菌T10产生的EPS可通过减少肠道损伤和增强小鼠肠道屏障功能来缓解葡聚糖硫酸钠诱导的结肠炎。EPS被归类为平均分子量为23.0 kDa的杂多糖。它主要由甘露糖、葡萄糖和核糖组成。这些发现对于用于生产具有胞外多糖菌株特异性特征的益生菌和后生元的乳酸杆菌的靶向筛选具有实际意义。