PDF(Pubmed)
Abstract：
The gut microbiota has been implicated as a driver of irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). Recently we described, mucosal biofilms, signifying alterations in microbiota composition and bile acid (BA) metabolism in IBS and ulcerative colitis (UC). Luminal oxygen concentration is a key factor in the gastrointestinal (GI) ecosystem and might be increased in IBS and UC. Here we analyzed the role of archaea as a marker for hypoxia in mucosal biofilms and GI homeostasis. The effects of archaea on microbiome composition and metabolites were analyzed via amplicon sequencing and untargeted metabolomics in 154 stool samples of IBS-, UC-patients and controls. Mucosal biofilms were collected in a subset of patients and examined for their bacterial, fungal and archaeal composition. Absence of archaea, specifically Methanobrevibacter, correlated with disrupted GI homeostasis including decreased microbial diversity, overgrowth of facultative anaerobes and conjugated secondary BA. IBS-D/-M was associated with absence of archaea. Presence of Methanobrevibacter correlated with Oscillospiraceae and epithelial short chain fatty acid metabolism and decreased levels of Ruminococcus gnavus. Absence of fecal Methanobrevibacter may indicate a less hypoxic GI environment, reduced fatty acid oxidation, overgrowth of facultative anaerobes and disrupted BA deconjugation. Archaea and Ruminococcus gnavus could distinguish distinct subtypes of mucosal biofilms. Further research on the connection between archaea, mucosal biofilms and small intestinal bacterial overgrowth should be performed.
摘要：
肠道微生物群被认为是肠易激综合征(IBS)和炎症性肠病(IBD)的驱动因素。最近我们描述，粘膜生物膜，IBS和溃疡性结肠炎（UC）中微生物群组成和胆汁酸（BA）代谢的变化。管腔氧浓度是胃肠道（GI）生态系统中的关键因素，在IBS和UC中可能会增加。在这里，我们分析了古细菌作为粘膜生物膜和胃肠道稳态中缺氧标志物的作用。通过扩增子测序和非靶向代谢组学分析了古细菌对154个IBS-粪便样品中微生物组组成和代谢物的影响，UC患者和对照。在一部分患者中收集粘膜生物膜，并检查其细菌，真菌和古细菌成分。没有古细菌，特别是甲烷杆菌,与胃肠道稳态破坏相关，包括微生物多样性减少，兼性厌氧菌和共轭二级BA的过度生长。IBS-D/-M与缺乏古细菌有关。甲那巴杆菌的存在与螺旋藻科和上皮短链脂肪酸代谢相关，并降低了gnavus的Ruminococus水平。粪便中不存在甲氧西林杆菌可能表明胃肠环境缺氧较少，减少脂肪酸氧化，兼性厌氧菌的过度生长和BA解共轭的破坏。古生菌和牙本质反刍动物可以区分粘膜生物膜的不同亚型。进一步研究古细菌之间的联系，应进行粘膜生物膜和小肠细菌过度生长。
