Diverse microbial signatures within the intestinal microbiota have been associated with intestinal and systemic inflammatory diseases, but whether these candidate microbes actively modulate host phenotypes or passively expand within the altered microbial ecosystem is frequently not known. Here we demonstrate that colonization of mice with a member of the genus Prevotella, which has been previously associated to colitis in mice, exacerbates intestinal inflammation. Our analysis revealed that Prevotella intestinalis alters composition and function of the ecosystem resulting in a reduction of short-chain fatty acids, specifically acetate, and consequently a decrease in intestinal IL-18 levels during steady state. Supplementation of IL-18 to Prevotella-colonized mice was sufficient to reduce intestinal inflammation. Hence, we conclude that intestinal Prevotella colonization results in metabolic changes in the microbiota, which reduce IL-18 production and consequently exacerbate intestinal inflammation, and potential systemic autoimmunity.

中文翻译：

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Prevotella spp 对肠道微生物组的扰动。增强宿主对粘膜炎症的易感性。

肠道微生物群中的多种微生物特征与肠道和全身炎症性疾病有关，但这些候选微生物是主动调节宿主表型还是被动地在改变的微生物生态系统中扩张通常是未知的。在这里，我们证明了普雷沃氏菌属（Prevotella）成员在小鼠体内的定植会加剧肠道炎症，普雷沃氏菌以前与小鼠的结肠炎有关。我们的分析表明，肠普雷沃氏菌改变了生态系统的组成和功能，导致短链脂肪酸（特别是乙酸盐）减少，从而导致稳态期间肠道 IL-18 水平降低。向普雷沃氏菌定植的小鼠补充 IL-18 足以减少肠道炎症。因此，