Shi Jialu, Du Peng, Xie Qinggang, Wang Nana, Li Huizhen, Smith Etareri Evivie, Li Chun, Liu Fei, Huo Guicheng, Li Bailiang
Key Laboratory of Dairy Science, Ministry of Education, Northeast Agricultural University, Harbin 150030, China.
Food Funct. 2020 Dec 1;11(12):10736-10747. doi: 10.1039/d0fo02622k. Epub 2020 Nov 24.
Tryptophan is an essential amino acid for the human body, whose intake is through the diet. Several studies support the theory that microbiota-derived tryptophan metabolite played a crucial role in maintaining the balance between gut microbiota and the mucosal immune system. Previously, we selected the Lactobacillus plantarum KLDS 1.0386 strain with high tryptophan-metabolic activity after the screening of 16 Lactobacillus strains. The current study aimed to assess the effects of L. plantarum KLDS 1.0386 combination with tryptophan in improving ulcerative colitis (UC) induced by dextran sodium sulfate (DSS) and the potential mechanisms involved. Our results showed that L. plantarum KLDS 1.0386 combined with tryptophan (LAB + Trp) decreased DAI score, MPO level, and pro-inflammatory cytokine (TNF-α, IL-1β, and IL-6) concentration. It also increased anti-inflammatory cytokine (IL-10) production, tight junction proteins (claudin-1, occludin, and ZO-1), and mucin (MUC1 and MUC2) mRNA expressions. The level of indole-3-acetic acid (IAA), an important tryptophan metabolite in the liver, serum, and colon, was elevated after LAB + Trp treatment, which further upregulated aryl hydrocarbon receptor (AHR) mRNA expression to activate the IL-22/STAT3 signaling pathway. Moreover, the supplementation with LAB + Trp modulated gut microbiota composition. The present study provided novel insights that can be used to reduce the number of UC patients by employing a method utilizing tryptophan-catabolizing Lactobacillus strains.
色氨酸是人体必需的氨基酸，通过饮食摄入。多项研究支持这样一种理论，即微生物群衍生的色氨酸代谢产物在维持肠道微生物群与黏膜免疫系统之间的平衡中起着关键作用。此前，我们在筛选了16株乳酸杆菌菌株后，选择了具有高色氨酸代谢活性的植物乳杆菌KLDS 1.0386菌株。本研究旨在评估植物乳杆菌KLDS 1.0386与色氨酸联合使用对改善葡聚糖硫酸钠（DSS）诱导的溃疡性结肠炎（UC）的效果及其潜在机制。我们的结果表明，植物乳杆菌KLDS 1.0386与色氨酸联合使用（LAB + Trp）降低了疾病活动指数（DAI）评分、髓过氧化物酶（MPO）水平和促炎细胞因子（TNF-α、IL-1β和IL-6）浓度。它还增加了抗炎细胞因子（IL-10）的产生、紧密连接蛋白（claudin-1、occludin和ZO-1）以及黏蛋白（MUC1和MUC2）的mRNA表达。LAB + Trp处理后，肝脏、血清和结肠中重要的色氨酸代谢产物吲哚-3-乙酸（IAA）水平升高，这进一步上调了芳烃受体（AHR）的mRNA表达，以激活IL-22/STAT3信号通路。此外，补充LAB + Trp调节了肠道微生物群的组成。本研究提供了新的见解，可用于通过采用利用色氨酸分解代谢乳酸杆菌菌株的方法来减少UC患者的数量。
