Department of Internal Medicine, Ersta Hospital, Stockholm, Sweden.
Department of Gastroenterology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
Clin Transl Gastroenterol. 2019 Jul;10(7):e00065. doi: 10.14309/ctg.0000000000000065.
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.
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.
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.
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.
在炎症性肠病（IBD）中，对肠道微生物群的异常免疫反应很重要，但微生物群在胶原性结肠炎（CC）中的作用在很大程度上尚不清楚。我们旨在比较 CC 患者与健康对照和 IBD 患者的粪便微生物群。
收集 CC（n=29）、年龄和性别匹配的健康对照（n=29）、克罗恩病（n=32）和溃疡性结肠炎（n=32）患者的粪便样本。通过 454 测序对 16S rRNA 基因扩增子进行测序，获得序列数据，并对获得的序列进行分类。
相似性分析显示，随着分类分辨率的增加，CC 患者与健康对照之间存在明显的分离，在比较操作分类单位数据时具有统计学意义（P=0.006）。CC 有 10 种不同分类单元的丰度较低。分类单元特异性分析显示，CC 患者中属于 Ruminococcaceae 科的几个操作分类单元的丰度持续较低，经错误发现率校正后 q < 0.05。仅在 CC 患者中有活动期疾病和/或皮质类固醇治疗时观察到这些分类单元的丢失，与 IBD 患者的发现相似。
CC 与主要见于活动期或正在接受皮质类固醇治疗的患者的特定粪便微生物群相关，而缓解期 CC 患者的微生物群与健康对照相似。值得注意的是，包括 Ruminococcaceae 科在内的关键分类单元的变化也在 IBD 中观察到。CC 和 IBD 的发病机制可能存在共同机制。
