急性肝衰竭小鼠回肠、结肠以及粪便菌群变化的研究

发布时间：2018-04-06 00:11

  本文选题：肠道微生态　切入点：急性肝衰竭　出处：《贵州医科大学》2017年硕士论文

【摘要】：目的:探讨急性肝衰竭小鼠肠道微生态菌群的变化,寻找特征性差异菌,为急性肝衰竭肠道微生态紊乱的诊治提供依据。方法:BALB/c雄鼠30只(空白组5只,模型组25只),D-氨基半乳糖制造小鼠急性肝衰竭模型。提取小鼠下消化道不同节段(回肠、结肠)内容物及粪便的微生物DNA,进行PCR扩增,对16S V3-V4区进行高通量测序,利用生物信息学分析技术对测序结果进行OTU聚类,物种注释,α多样性分析,LEf Se(LDA Effect Size)分析,寻找模型组特征性差异菌。结果:2组小鼠,共存活10只,其中模型组死亡率为80%。回肠、结肠内容物及粪便共30个样本,测序覆盖深度97%。α多样性分析显示急性肝衰竭小鼠回肠中细菌丰度增加(chao1指数105.7±18.4与149.3±55,P0.01),多样性增加(shannon指数2.5±0.1与2.8±0.8,P0.05);结肠中细菌丰度减低(chao1指数285.4±46.1与276.98±46.7,P0.05)及多样性增加(shannon指数4.9±0.3与5.65±0.39,P0.01),粪便中细菌多样性降低(shannon指数5.1±0.3与4.87±0.29,P0.01),丰度(chao1指数270.1±53.7与250.2±54.4,P=0.067)无显著差异。模型组肠道菌群与空白组相比小鼠肠道中检测到10个菌门,以厚壁菌门、拟杆菌门和变形菌门为主。模型组回肠中细菌门水平差异无统计学意义;结肠中拟杆菌门比例增加(9.3%±7.9%与33.8%±18.2%,P=0.0240.05),TM7菌门比例增加(0.2%±0.3%与2.2%±1.6%,P=0.0290.05);粪便中厚壁菌门减少(32.8%±20.5%与10.2%±5.5%,P=0.05)、拟杆菌门增加(57.3%±23.4%与86.1%±67.2%,P=0.07),但差异无统计学意义。在最佳分类水平上,回肠梭菌科丰度减少(44.95%±19.28%与7.51%±16.57%,P0.05),结肠理研菌科(1.08%±1.01%与4.18%±2.39%,P0.05)、S24-7(4.75%±4.87%与22.77%±13.05%,P0.05)、F16(0.24%±0.28%与2.18%±1.61%,P0.05)等丰度增加。LEf Se(LDA Effect Size)分析显示两组在葡萄球菌科、S24-7方面差异有统计学意义,其中S24-7可定义为特征性差异菌群。结论:不同节段肠道拥有不同的肠道菌群结构,急性肝衰竭小鼠肠道微生态紊乱,回肠菌群过度生长。急性肝衰竭与S24-7过度生长有相关性。
[Abstract]:Objective: to investigate the changes of intestinal microecological flora in mice with acute liver failure and to find out the characteristic differential bacteria to provide evidence for the diagnosis and treatment of intestinal microecological disorder in acute liver failure.Methods the acute liver failure model was established in 30 male mice (5 in the blank group and 25 in the model group) with D-galactosamine (D-galactosamine).The microbial DNA of different segments of the lower digestive tract (ileum, colon) and feces of mice were extracted and amplified by PCR. The 16s V3-V4 region was sequenced by high-throughput sequencing. The sequencing results were clustered by OTU using bioinformatics analysis technique.Species annotation, 伪 -diversity analysis and LEF Se(LDA Effect size analysis were used to find the characteristic differential bacteria in the model group.Results there were 10 mice survived in the 2 groups, and the mortality of the model group was 80%.There were 30 samples of ileum, colon contents and feces.There was no significant difference in bacterial diversity between 4.9 卤0.3 and 5.65 卤0.39 (P 0.01), but there was no significant difference in bacterial diversity in feces between 5.1 卤0.3 and 4.87 卤0.29 (P 0.01) and 270.1 卤53.7 and 250.2 卤54.4 (P 0.067).Ten phylum were detected in the intestinal tract of the model group compared with that in the blank group, and the main ones were phylum thunbergiformis, Bacteroides sp., and Proteus phylum.妯″瀷缁勫洖鑲犱腑缁嗚弻闂ㄦ按骞冲樊寮傛棤缁熻�″�︽剰涔，

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