Gut microbiome community structure is associated with Crohn's disease (CD) development and response to therapy. Bile acids (BAs) play a central role in modulating intestinal immune responses, and changes in gut bacterial communities can profoundly alter the intestinal BA pool. The liver synthesizes and conjugates primary bile acids (priBAs) that are then deconjugated, epimerized, and dehydroxylated by gut bacteria to produce secondary bile acids (secBAs). We investigated the relationship between the gut microbiome and the fecal BA pool in stool samples obtained from a well-characterized cohort of pediatric CD patients undergoing nutritional therapy to induce disease remission. We found that fecal BA composition was altered in a sub-group of CD patients who did not sustain remission. The microbial community structures associated with priBA and secBA-dominant profiles were distinct. In addition, the fecal BA concentrations were correlated with the abundance of distinct bacterial taxonomic groups. Finally, priBA dominant samples were associated with community-level decreases in enzymes for dehydroxylation but not deconjugation.

中文翻译：

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小儿克罗恩病粪便胆汁酸与微生物群落结构的关系。

肠道微生物群落结构与克罗恩病 (CD) 的发展和对治疗的反应有关。胆汁酸 (BA) 在调节肠道免疫反应中发挥核心作用，肠道细菌群落的变化可以深刻改变肠道 BA 池。肝脏合成并结合初级胆汁酸 (priBA)，然后由肠道细菌解结合、差向异构化和脱羟基，从而产生次级胆汁酸 (secBA)。我们研究了肠道微生物组与粪便样本中粪便 BA 池之间的关系，这些样本取自一个特征明确的接受营养治疗以诱导疾病缓解的儿科 CD 患者队列。我们发现粪便 BA 成分在未维持缓解的 CD 患者亚组中发生了改变。与 priBA 和 secBA 优势谱相关的微生物群落结构是不同的。此外，粪便 BA 浓度与不同细菌分类群的丰度相关。最后，priBA 占主导地位的样本与群落水平的脱羟基酶减少有关，但与去共轭无关。