INTRODUCTION In inflammatory bowel disease (IBD), an aberrant immune response to gut microbiota is important, but the role of the microbiota in collagenous colitis (CC) is largely unknown. We aimed to characterize the microbiota of patients with CC compared with that of healthy control and patients with IBD. METHODS Fecal samples were collected from patients with CC (n = 29), age- and sex-matched healthy controls (n = 29), patients with Crohn's disease (n = 32), and patients with ulcerative colitis (n = 32). Sequence data were obtained by 454 sequencing of 16S rRNA gene amplicons, and the obtained sequences were subsequently taxonomically classified. RESULTS Analysis of similarity statistics showed a segregation between patients with CC and healthy controls with increasing taxonomic resolution, becoming significant comparing operational taxonomic unit data (P = 0.006). CC had a lower abundance of 10 different taxa. Taxa-specific analyses revealed a consistent lower abundance of several operational taxonomic units belonging to the Ruminococcaceae family in patients with CC, q < 0.05 after false discovery rate correction. Loss of these taxa was seen in patients with CC with active disease and/or corticosteroid treatment only and resembled the findings in patients with IBD. DISCUSSION CC is associated with a specific fecal microbiome seen primarily in patients with active disease or ongoing corticosteroid treatment, whereas the microbiome of CC patients in remission resembled that of healthy controls. Notably, the shift in key taxa, including the Ruminococcaceae family, was also observed in IBD. There may be common mechanisms in the pathogenesis of CC and IBD.

中文翻译：

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胶原性结肠炎中的肠道菌群具有与炎症性肠病相关的营养不良的特征。

引言在炎症性肠病（IBD）中，对肠道菌群的异常免疫反应很重要，但是该菌群在胶原性结肠炎（CC）中的作用尚不清楚。我们旨在表征与健康对照组和IBD患者相比，CC患者的微生物群。方法从CC患者（n = 29），年龄和性别相匹配的健康对照者（n = 29），克罗恩氏病（n = 32）和溃疡性结肠炎（n = 32）患者中收集粪便样本。通过对16S rRNA基因扩增子进行454测序获得序列数据，然后对获得的序列进行分类学分类。结果对相似性统计数据的分析显示，随着分类学分辨率的提高，CC患者与健康对照组之间的隔离，在比较业务分类单位数据时变得非常重要（P = 0.006）。CC的丰度较低，有10种不同的分类单元。特定分类群的分析显示，在错误发现率校正后，CC患者中属于Ruminococcaceae科的几个操作分类单位的一致性较低，q <0.05。仅在患有活动性疾病和/或接受皮质类固醇治疗的CC患者中看到这些分类单元的丧失，与IBD患者的发现相似。讨论CC与特定的粪便微生物组有关，主要见于活动性疾病或正在进行糖皮质激素治疗的患者，而缓解期CC患者的微生物组与健康对照者相似。值得注意的是，在IBD中也观察到关键类群的转移，包括Ruminococcaceae科。