阑尾对肠道微生物影响的研究

发布时间：2018-05-30 02:04

  本文选题：阑尾 + 高通量测序　； 参考：《南方医科大学》2017年硕士论文

【摘要】：背景与目的人类肠道细菌有1013-1014个细菌,已发现很多疾病的发生、发展都与肠道菌群的异常存在着关联,不少学者开始关注肠道微生物与不同疾病发病的关系。阑尾曾被认为是在进化过程中残余的器官,然而,越来越多的回顾性研究揭示了阑尾切除与肠道疾病发病的关系,关于其机制的猜想倾向于与阑尾对肠道微生物和免疫的影响,然而相关研究有限。目前16SrDNA测序和宏基因组测序已广泛应用于微生物的研究。本研究拟用16s rDNA测序和宏基因组测序的手段检测有阑尾切除手术史和无阑尾切除手术史的受试者的大便标本的微生物情况,以研究:有阑尾切除术史的受试者的大便样本的微生物物种和功能的结构和丰度,分析其与无手术史的受试者的异同,以及探讨存在的差异与炎症性肠病和大肠癌等疾病发病之间可能的关系。方法16srDNA扩增子测序分别收集有阑尾切除手术史(实验组)和无阑尾切除手术史(对照组)的受试者的大便标本1份,分别提取粪便基因组DNA,扩增细菌16srDNAV4片段,采用16srDNA测序的方法得出测序信息,经GreenGene数据库确定物种信息,对细菌进行结构和丰度分析。宏基因组测序对部分16srDNA测序的剩余样品提取基因组DNA,经样品检测、建库、宏基因组测序、数据质控、组装、基因预测、物种和功能注释,对微生物进行物种和功能的分析。结果1.两组粪便肠道微生物以细菌为主,占肠道微生物的95%以上,在门水平均以拟杆菌门,厚壁菌门和变形菌门为主;2.两组粪便微生物组成有微生物群落结构和丰度的差异,其中G_Prevotella,G_Sutterella,S Prevotella bryantii,S_Bacteroides_sp_CAG_530,S_Bacteroides_coprophilu,S_Oscillibacter_sp_ER4,S_Ruminococcus_sp_CAG_177,S_Prevotella_sp_KHD1,S_Clostridium_sp_CAG_138,S_Clostridium_sp_CAG_127,S_Prevotella_sp_CAG_520,S_Bacteroides_plebeius,S_Bacteroides_plebeius_CAG_211 在对照组中富集,而 S_Bacteroides_fragilis,S_Bacteroides_uniformis在实验组富集。3.两组粪便微生物功能有差异,其中阑尾切除术组中碳水化合物酶富集,与心血管疾病、内分泌代谢疾病、次级代谢物的合成、脂肪代谢通路相关的基因相对丰度显著增加,而与细胞生长与死亡、复制和修复、翻译、能量代谢、氨基酸和核酸代谢以及免疫系统等通路相关的基因相对丰度明显降低。结论阑尾切除改变了肠道微生物的组成和功能,阑尾对肠道微生物有影响。特殊分类群和基因在阑尾切除术后组富集,可能与阑尾切除术后消化系统、心血管系统、内分泌系统等疾病有关。
[Abstract]:Background and objective there are 1013-1014 bacteria in human intestinal tract. Many diseases have been found and the development is related to the abnormality of intestinal flora. Many scholars have begun to pay attention to the relationship between intestinal microbes and the pathogenesis of different diseases. The appendix was once thought to be a residual organ during evolution. However, more and more retrospective studies have revealed the relationship between appendectomy and the pathogenesis of intestinal diseases, and speculation about its mechanism tends to relate to the effects of appendix on intestinal microorganism and immunity. However, the relevant research is limited. At present, 16SrDNA sequencing and macro genome sequencing have been widely used in the study of microbes. In this study, 16 s rDNA sequencing and macro genome sequencing were used to detect the microbial status of stool specimens from subjects with and without appendectomy. To study the structure and abundance of microbial species and function in stool samples of subjects with a history of appendectomy, and analyze their similarities and differences with those without surgical history. And to explore the possible relationship between the differences and inflammatory bowel disease, colorectal cancer and other diseases. Methods one stool specimen with appendectomy history (experimental group) and no appendectomy history (control group) was collected by 16srDNA amplification. Fecal genomic DNA was extracted and bacterial 16srDNAV4 fragments were amplified. The 16srDNA sequencing method was used to obtain the sequencing information. The species information was determined by GreenGene database and the structure and abundance of bacteria were analyzed. Genomic DNA was extracted from the remaining samples of partial 16srDNA sequencing. The species and function of microorganisms were analyzed by sample detection, library construction, macro genome sequencing, data quality control, assembly, gene prediction, species and functional annotation. Result 1. Bacteria were the main microorganism in fecal tract in both groups, accounting for more than 95% of the intestinal microbes, and Bacteroides phylum, Typhylum and Proteus were the main bacteria at the portal level. 涓ょ粍绮�渚垮井鐢熺墿缁勬垚鏈夊井鐢熺墿缇よ惤缁撴瀯鍜屼赴搴︾殑宸�寮，

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