Institute of Digestive Disease, Department of Medicine and Therapeutics, Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong, Hong Kong.
J Gastroenterol Hepatol. 2013 Oct;28(10):1624-31. doi: 10.1111/jgh.12306.
In irritable bowel syndrome (IBS), the gut microbiota may be altered. Probiotic bacteria appear to be therapeutically effective. We characterized the mucosa-associated microbiota, and determined the clinical and microbiological effects of orally administered probiotic bacteria, in patients with IBS.
Mucosal microbiota from rectal biopsies of IBS patients and controls were assessed on the V1 and V2 variable regions of the 16S ribosomal RNA gene amplified using 454 pyrosequencing. Clinical symptoms and changes in mucosal microbiota were assessed in IBS patients before and after 4 weeks of treatment with probiotic mix VSL#3.
Ten IBS subjects (eight female; mean age 46 years) were included. At week 4 of probiotic therapy, six patients showed symptom improvement on global symptom assessment compared with baseline (P = 0.031). Before therapy, intestinal microbiota of IBS subjects differed significantly from that of healthy controls, with less diversity and evenness than controls (n = 9; P < 0.05), increased abundance of Bacteroidetes (P = 0.014) and Synegitestes (P = 0.017), and reduced abundance of Actinobacteria (P = 0.004). The classes Flavobacteria (P = 0.028) and Epsilonproteobacteria (P = 0.017) were less enriched in IBS. Abundance differences were largely consistent from the phylum to genus level. Probiotic treatment in IBS patients was associated with a significant reduction of the genus Bacteroides (all taxonomy levels; P < 0.05) to levels similar to that of controls.
In this pilot study, global and deep molecular analysis demonstrates an altered mucosal microbiota composition in IBS. Probiotic leads to detectable changes in the microbiota. These effects of probiotic bacteria may contribute to their therapeutic benefit.
在肠易激综合征（IBS）中，肠道微生物群可能会发生改变。益生菌似乎具有治疗效果。我们对黏膜相关微生物群进行了特征描述，并确定了口服益生菌对 IBS 患者的临床和微生物学影响。
使用 454 焦磷酸测序扩增 16S 核糖体 RNA 基因的 V1 和 V2 可变区，评估 IBS 患者和对照直肠活检黏膜微生物群。在接受益生菌混合物 VSL#3 治疗 4 周前后，评估 IBS 患者的临床症状和黏膜微生物群变化。
纳入 10 名 IBS 患者（8 名女性；平均年龄 46 岁）。在益生菌治疗的第 4 周，与基线相比，6 名患者的整体症状评估显示症状改善（P=0.031）。在治疗前，IBS 患者的肠道微生物群与健康对照组有显著差异，与对照组相比，多样性和均匀度较低（n=9；P<0.05），厚壁菌门（P=0.014）和 Synegitestes（P=0.017）丰度增加，而放线菌门（P=0.004）丰度降低。黄杆菌纲（P=0.028）和ε变形菌纲（P=0.017）在 IBS 中较少富集。从门到属水平，丰度差异基本一致。IBS 患者的益生菌治疗与属水平的拟杆菌属（所有分类学水平；P<0.05）显著减少有关，使其水平与对照组相似。
在这项初步研究中，全面和深入的分子分析表明 IBS 存在黏膜微生物群组成的改变。益生菌会导致微生物群发生可检测的变化。这些益生菌细菌的作用可能有助于其治疗效果。
