溃疡性结肠炎（UC）是一种与肠道菌群失调引起的免疫系统功能障碍相关的炎症性肠道疾病。本研究旨在使用兼具特定的Lactobacillus acidophilus LA85临床治疗体内的异戊糖硫酸钠（DSS）诱导的UC小鼠模型，研究其对结肠炎的缓解作用及其潜在机制。UC小鼠模型是通过将C57BL/6J雄性小鼠饮用含有2.5%（w/v）DSS的水处理7天来建立的。这些小鼠每天接受L. acidophilus LA85（1 × 109个菌落形成单位/天）或200µL无菌水（LA85处理组和UC模型组各自）的补充。随后，在第21天分析了小鼠的疾病活动指数（DAI）、结肠长度和结肠组织的组织学变化，并研究了L. acidophilus LA85对肠道微生物群和血清炎症细胞因子的影响。与UC模型小鼠相比，L. acidophilus LA85处理的UC小鼠显示出显著减轻结肠炎症状的作用，包括体重下降、DAI评分、结肠缩短和结肠组织损伤。另外，Lactobacillus acidophilus LA85补充物还显著降低了血清肿瘤坏死因子α和白细胞介素6的浓度，同时增加了血清白细胞介素10的浓度。此外，LA85补充物改善了肠道微生物群的多样性和组成，这两者都是由于DSS的作用而降低的。特别是，L. acidophilus LA85处理的UC小鼠相比UC模型小鼠，显示出Akkermansia和Romboutsia的相对丰度更高。这些结果表明，L. acidophilus LA85可以通过调节免疫反应和恢复肠道微生物群来缓解肠道炎症疾病，如炎症性肠道疾病。实用应用：溃疡性结肠炎是一种由肠道微生物群失衡引起的炎症性肠道疾病。本研究表明，L. acidophilus LA85能通过调节炎症细胞因子、保护肠道屏障和调节特定肠道微生物群来缓解DSS诱导的结肠炎小鼠。L. acidophilus LA85是治疗UC的有希望的益生菌候选物。©2023食品科技学会。

Ulcerative colitis (UC) is a type of inflammatory bowel disease associated with immune system dysfunction caused by gut dysbiosis. This study aimed to investigate the alleviating effect of Lactobacillus acidophilus LA85 on colitis and its underlying mechanism using mouse models of dextran sulfate sodium (DSS)-induced UC. The UC mouse models were established by treating C57BL/6J male mice with 2.5% (w/v) DSS in drinking water for 7 days. These mice received supplementation with either L. acidophilus LA85 (1 × 109 colony-forming units/day) or 200 µL of sterile water once daily (LA85-treated and UC model mice, respectively). The disease activity index (DAI), colon length, and histological changes in the colons of mice were then analyzed at Day 21, and the effects of L. acidophilus LA85 on the gut microbiota and serum inflammatory cytokines were also investigated. Compared with the UC model mice, L. acidophilus LA85-treated UC mice showed significant reductions in a variety of colitis symptoms, including weight loss, the DAI score, colon shortening, and colon tissue damage. Lactobacillus acidophilus LA85 supplementation also significantly decreased the serum concentrations of tumor necrosis factor α and interleukin-6 while increasing the serum concentration of IL-10. Furthermore, LA85 supplementation improved the diversity and composition of the gut microbiota, both of which had been decreased by DSS. In particular, L. acidophilus LA85-treated UC mice showed higher relative abundances of Akkermansia and Romboutsia than the UC model mice. These results demonstrate that L. acidophilus LA85 can alleviate inflammatory diseases of the intestine, such as inflammatory bowel disease, by regulating immune responses and restoring the gut microbiota. PRACTICAL APPLICATION: Ulcerative colitis is a type of inflammatory bowel disease caused by imbalance of gut microbiota. This study showed that L. acidophilus LA85 can alleviate DSS-induced colitis in mice through regulation of inflammatory cytokines, protection of intestinal barrier, and regulation of specific gut microbiota. L. acidophilus LA85 is a promising probiotic candidate for the treatment of UC.© 2023 Institute of Food Technologists.