基于多中心数据探索肠道菌群对结直肠息肉的预测作用

Predictive effect of gut microbiota on colorectal polyp based on multi-center data

目的比较结直肠息肉患者与正常人群的肠道菌群,探索差异菌群与结直肠息肉的关系。方法本研究采用横断面设计方案,收集2021年2月至2022年2月期间,在我国西南地区5家三甲医院消化内科经肠镜检查提示结直肠息肉的75名患者为息肉组,肠镜检查未见异常的73名患者为对照组。采用16S rRNA测序分析方法,比较2组患者肠镜检查前大便标本的菌群差异;采用京都基因和基因组百科全书数据库比对方法,分析具有显著性差异的代谢通路信息;采用随机森林方法分析菌群显著差异物种及其预测作用。结果2组患者年龄、性别、体质量指数(body mass index,BMI)等基线资料比较差异无统计学意义。息肉组与对照组肠道菌群结构存在明显差异(Bray-curtis,weighted unifrac,P<0.05),息肉组粪杆菌属(Faecalibacterium)(P<0.001)及瘤胃球菌属_2(Ruminococcus_2)(P<0.05)明显减少,而假单胞菌属(Pseudomonas)明显增多(P<0.05)。肠道菌群功能分析结果显示,息肉组氨酰基-tRNA生物合成(P<0.05)、核糖体合成(P<0.01)、错配修复(P<0.05)及同源重组(P<0.01)功能较对照组明显降低。随机森林分析显示肠道菌群对结直肠息肉的发生具有预测作用(AUC=0.756),其中粪杆菌属预测作用最强。结论结直肠息肉患者较正常人群的肠道菌群特征发生改变,其中粪杆菌属差异最显著,其可能与结直肠息肉的形成相关。

Objective To explore the correlation between different flora and colorectal polyp via comparing the gut microbiota between patients with colorectal polyp and healthy population.Methods A cross-sectional study was conducted on 75 patients with colorectal polyp(polyp group)and 73 patients with no abnormal colonoscopy(control group)indicated by colonoscopy from Department of Gastroenterology of 5 Class-A tertiary hospitals in Southwest China from February 2021 to February 2022.16S rRNA gene sequence analysis was used to compare the bacterial flora in stool samples before colonoscopy between the 2 groups.The metabolic pathway information with signifcant differences was analyzed by comparing the data of Kyoto Encyclopedia of Genes and Genomes(KEGG).The random forest method was used to analyze the species with significant difference of flora and its predictive efct.Results There were no significant differences in age,sex and body mass index(BMI)between these 2 groups.There were significant differences in gut microbiota structure between the polyp group and control group(Bray-curtis,weighted unifrac,P<0.05),and Faecalibacterium(P<0.001)and Ruminococcus_2(P<0.05)in the polyp group significantly decreased,while Pseudomonas was significantly increased(P<0.05).Gut microbiota function analysis showed that the function of aminoacyI-tRNA biosynthesis(P<0.05),ribosome synthesis(P<0.01),mismatch repair(P<0.05)and homologous recombination(P<0.01)was significantly reduced in polyp group.Random forest analysis showed that gut microbiota could predict the occurrence of colorectal polyp(AUC=0.756)and Faecalibacterium had the strongest prediction effect.Conclusion Patients with colorectal polyp show the changed features of gut microbiota compared with normal people.The difference of Faecalibacterium is the most significant,Which may be related to the formation of colorectal polyp.