生活在牧区和城市环境下蒙古族人群肠道菌群的比较分析

发布时间：2018-04-09 12:04

本文选题：肠道菌群　切入点：蒙古族人群　出处：《内蒙古农业大学》2012年硕士论文

【摘要】：诸多研究表明宿主的基因型、性别、年龄、生理和心理状况等因素对人体肠道微生物的结构组成具有显著的影响作用,然而关于生活方式因素对肠道微生物影响的专题研究还相对较少。随着城市化进程的加快,蒙古族人群的生活方式差异不断加大,仍然生活在牧区的蒙古族居民依旧沿袭了几千年的传统生活方式,过着游牧的生活,饮食主要以发酵乳制品和牛羊肉为主；而迁徙到城市的蒙古族人群在享受到现代文明发展成果的同时,其膳食结构也发生了明显的变化,日常饮食中发酵乳制品的摄入量显著降低的同时水果和蔬菜的摄入量明显升高。因此,选择上述两类人群作为研究对象可以更好地了解生活方式对肠道菌群结构的影响。本研究以生活在锡林郭勒盟牧区和呼和浩特市城区的蒙古族健康青年人群(19-35岁,BMI:18.5-24.0kg/m2)为研究对象,通过PCR-DGGE和q-PCR分子生物学手段对其肠道菌群进行了多样性分析和定量分析。研究发现,两类人群肠道菌群的两大优势菌群均为Firmicutes和Bacteroidetes,且Ruminococcus、Faecalibacterium prausnitzii及Y-变形菌纲为人体肠道最优势菌。然而研究还发现,牧区人群肠道菌群中的Atopobium cluster、Bacteroides group、Desulfovibrio genus、Faecalibacterium prausnitzii、Lactobacillus和Bifidobacterium含量均高于城市人群,且双歧杆菌组间差异非常显著(p0.01),而牧区人群肠道菌群中的Clostridium含量极显著低于其在城市人群肠道中的含量(p0.001)。对Lactobacillus和Bifidobacterium中常见菌种的定性分析结果显示,LCasei存在于两组所有个体,L. Plantarum在牧区人群中的存在比例略低于城市人群,而L. Brevis、L. Acidophilus、L. helveticus和L. Fermentum在牧区人群的检出率均高于城市人群；Bifidobacterium内除了B. Angulatum在牧区人群的检出率显著低于城市人群,其余的B. infantis、B. longum和B. Breve及B. Adolescentis在牧区人群的检出率均高于城市人群,且B. Infantis和B. Adolescentis在两类人群中的检出率差异较大。由此可见,两类人群肠道微生物的构成存在较大地差异。通过对粪便中有机酸的测定发现,牧区人群肠道中总胆汁酸的含量略低于城市人群,而乙酸和丙酸的含量均高于城市人群。研究还发现,Clostridium的含量与碳水化合物摄入呈正相关(r=0.50,p0.01),与脂肪摄入量呈负相关(r=-0.60,p0.01)。因此本研究认为,生活方式中膳食结构的不同,尤其是发酵乳制品的摄入量不同,可能是导致生活在牧区和城市环境下蒙古族人群肠道微生物结构组成不同的主要原因。本课题的开展旨在为蒙古族人群肠道菌群的基础研究提供一定的参考,同时发掘饮食结构等生活方式对肠道菌群的塑造。
[Abstract]:Many studies have shown that host genotypes, sex, age, physiological and psychological conditions have a significant impact on the structure of human intestinal microbes.However, there are relatively few studies on the effects of lifestyle factors on intestinal microbes.With the acceleration of urbanization, the difference of the Mongolian people's way of life is increasing. The Mongolian people who still live in pastoral areas still follow the traditional way of life for thousands of years and lead a nomadic life.The diet mainly consisted of fermented dairy products and beef and mutton; while the Mongolian people who migrated to the city enjoyed the fruits of the development of modern civilization, their diet structure also changed obviously.The intake of fermented dairy products in daily diet decreased significantly while the intake of fruits and vegetables increased significantly.Therefore, the above two groups can better understand the influence of lifestyle on intestinal flora structure.In this study, BMI: 18.5-24.0 kg / m2, a healthy young Mongolian population living in the pastoral area of Xilingol League and the urban area of Hohhot, was used to analyze the diversity and quantitative analysis of intestinal flora by PCR-DGGE and q-PCR molecular biology.It was found that Firmicutes and Bacteroidetes. were the two dominant microflora in the intestinal flora of the two groups, and that Ruminococcus sp. Faecalibacterium prausnitzii and Y- Proteus were the most dominant bacteria in human intestinal tract.However, it was also found that the contents of Atopobium clusteroides group Desulfovibrio genustii Faecalibacterium prausnitziiae Lactobacillus and Bifidobacterium in the intestinal flora of pastoral population were higher than those in urban population.The difference between bifidobacterium groups was very significant (p0.01), while the Clostridium content of intestinal flora in pastoral population was significantly lower than that in urban population.The results of qualitative analysis of the common strains of Lactobacillus and Bifidobacterium showed that the proportion of LCasei in all individuals of the two groups in pastoral population was slightly lower than that in urban population.In pastoral population, the detection rate of L. Brevisus L. Acidophilus L. helveticus and L. Fermentum in pastoral population was higher than that in urban population. The detection rate of B. Angulatum in pastoral population was significantly lower than that in urban population, and the detectable rates of B. infantis B. longum, B. Breve and B. Adolescentis in pastoral population were higher than those in urban population.The detection rates of B. Infantis and B. Adolescentis were different between the two groups.It can be seen that the composition of intestinal microbes in the two groups of people is quite different.The content of total bile acid in intestinal tract of pastoral population was slightly lower than that of urban population, while the content of acetic acid and propionic acid was higher than that of urban population.It was also found that the content of Clostridium was positively correlated with carbohydrate intake and negatively correlated with fat intake.Therefore, the difference of dietary structure in life style, especially the intake of fermented dairy products, may be the main reason for the different composition of intestinal microorganism in Mongolian people living in pastoral areas and urban environments.The purpose of this paper is to provide some reference for the basic research of intestinal flora of Mongolian people, and to explore the way of life such as dietary structure to shape the intestinal flora.
【学位授予单位】：内蒙古农业大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TS252.1

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