闌尾對腸道微生物影響的研究
發(fā)布時間:2018-05-30 02:04
本文選題:闌尾 + 高通量測序; 參考:《南方醫(yī)科大學》2017年碩士論文
【摘要】:背景與目的人類腸道細菌有1013-1014個細菌,已發(fā)現(xiàn)很多疾病的發(fā)生、發(fā)展都與腸道菌群的異常存在著關聯(lián),不少學者開始關注腸道微生物與不同疾病發(fā)病的關系。闌尾曾被認為是在進化過程中殘余的器官,然而,越來越多的回顧性研究揭示了闌尾切除與腸道疾病發(fā)病的關系,關于其機制的猜想傾向于與闌尾對腸道微生物和免疫的影響,然而相關研究有限。目前16SrDNA測序和宏基因組測序已廣泛應用于微生物的研究。本研究擬用16s rDNA測序和宏基因組測序的手段檢測有闌尾切除手術史和無闌尾切除手術史的受試者的大便標本的微生物情況,以研究:有闌尾切除術史的受試者的大便樣本的微生物物種和功能的結構和豐度,分析其與無手術史的受試者的異同,以及探討存在的差異與炎癥性腸病和大腸癌等疾病發(fā)病之間可能的關系。方法16srDNA擴增子測序分別收集有闌尾切除手術史(實驗組)和無闌尾切除手術史(對照組)的受試者的大便標本1份,分別提取糞便基因組DNA,擴增細菌16srDNAV4片段,采用16srDNA測序的方法得出測序信息,經GreenGene數(shù)據(jù)庫確定物種信息,對細菌進行結構和豐度分析。宏基因組測序對部分16srDNA測序的剩余樣品提取基因組DNA,經樣品檢測、建庫、宏基因組測序、數(shù)據(jù)質控、組裝、基因預測、物種和功能注釋,對微生物進行物種和功能的分析。結果1.兩組糞便腸道微生物以細菌為主,占腸道微生物的95%以上,在門水平均以擬桿菌門,厚壁菌門和變形菌門為主;2.兩組糞便微生物組成有微生物群落結構和豐度的差異,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 在對照組中富集,而 S_Bacteroides_fragilis,S_Bacteroides_uniformis在實驗組富集。3.兩組糞便微生物功能有差異,其中闌尾切除術組中碳水化合物酶富集,與心血管疾病、內分泌代謝疾病、次級代謝物的合成、脂肪代謝通路相關的基因相對豐度顯著增加,而與細胞生長與死亡、復制和修復、翻譯、能量代謝、氨基酸和核酸代謝以及免疫系統(tǒng)等通路相關的基因相對豐度明顯降低。結論闌尾切除改變了腸道微生物的組成和功能,闌尾對腸道微生物有影響。特殊分類群和基因在闌尾切除術后組富集,可能與闌尾切除術后消化系統(tǒng)、心血管系統(tǒng)、內分泌系統(tǒng)等疾病有關。
[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. 涓ょ粍綺究寰敓鐗╃粍鎴愭湁寰敓鐗╃兢钀界粨鏋勫拰涓板害鐨勫樊寮,
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