腹泻型肠易激综合征患者肠黏膜相关菌群及其与症状的关系研究

The study of mucosa-associated bacteria and their relations with symptoms of diarrhea predominant IBS by Fluorescence in Situ Hybridization

目的比较腹泻型肠易激综合征(diarrhea predominant irritable bowel syndrome,IBS-D)患者与健康对照者在总细菌、大肠杆菌、梭菌属、拟杆菌、双歧杆菌和乳酸菌等6种细菌的差异,并探究菌群与症状之间的相关性。方法选取2016年6月至2016年10月于西安交通大学第二附属医院消化内镜中心进行结肠镜检查的IBS-D患者20例及健康体检者16名。收集其肠道黏膜标本,制成冰冻切片后进行荧光原位杂交,对肠黏膜相关细菌进行观察计数,并分析其与临床表现之间的关系。结果 IBS-D患者肠黏膜中的细菌主要定植在黏膜表面及与之相邻的黏液层中,仅个别患者有极少量的细菌定植在黏膜深处的固有层中。与健康对照组相比,IBS-D患者肠黏膜相关菌群中的细菌总数、大肠杆菌、拟杆菌和梭菌属数量明显增多(P<0.05),双歧杆菌数量则明显减少(P<0.05),但二者在乳酸菌的数量上差异无统计学意义(P>0.05)。与健康对照组相比,IBS-D患者固有层中细菌数量差异无统计学意义(P>0.05)。在IBS-D中,腹痛程度评分与大肠杆菌数量、排便次数、乳酸菌的数量、对大便的满意情况与双歧杆菌之间有显著相关性(P<0.05),其他细菌的数量与其他IBS-D症状之间均无显著的相关性(P>0.05)。结论与健康对照组相比,IBS-D患者的肠道微生态发生了显著改变,总细菌、大肠杆菌、拟杆菌、梭菌属和双歧杆菌的数量均产生了变化,而这种变化则与IBS-D某些症状的严重程度具有一定的相关性。

Objective To investigate the mucosa-associated bacteria locations and compare the differences in the numbers of total bacteria,Escherichia coli(E.coli),Bacteroides,Clostridium,Lactobacillus and Bifidobacteria in mucosal samples between patients with diarrhea predominant irritable bowel syndrome(IBS-D) and healthy controls.Methods Twenty IBS-D patients and 16 healthy mucosal samples were collected in the Second Affiliated Hospital of Xi’an Jiaotong University from Jun.to Oct.2016.The samples were made to frozen slides,analyzed by fluorescent in situ hybridization(FISH),scanned by Fluorescence microscopy and compared with each other group.Results The mucosa-associated bacteria of IBS-D patients were mainly colonized in the mucosal surface and the adjacent mucus layer.Compared with healthy controls,the numbers of total bacteria,E.coli,Bacteroides and Clostridium were significantly higher in patients with IBS-D and Bifidobacteria was significantly lower(P<0.05).But there was no significant difference in the number of Lactobacillus between IBS-D group and the control group.Compared with healthy controls,the number of bacteria in the lamina propria in IBS-D were not significant changes(P>0.05).There were significant correlations between abdominal pain score and E.coli,between the number of defecation and Lactobacillus,and between the faecal satisfaction and Bifidobacteria(P<0.05).Conclusion The number of total bacteria and the 4 individual numbers of E.coli,Bacteroides,Clostridium and Bifidobacteria were changed in patients with IBS-D.There was a correlation between the intestinal microflora and some symptoms of IBS-D.