初生婴儿肠道菌群与母体各部位菌群相关性研究

发布时间：2018-02-11 02:51

本文关键词： 婴儿肠道菌群母婴菌群传递单分子实时测序微滴式数字PCR　出处：《内蒙古农业大学》2017年博士论文　论文类型：学位论文

【摘要】：人体是由自身细胞和微生物细胞共同组成的"超级生物体",其构建非一日之功。早期观点一致认为胎儿在母亲子宫中时其肠道内是无菌的,随着相关研究热度的日益提升,人们发现胎儿肠道菌群的构建可能在母体中就已开始,并且,母体的肠道、口腔、羊水、胎盘、产道、乳腺和皮肤等微生态环境都有可能为其提供微生物。然而时至今日,全面阐述母婴间菌群传递的相关论文却鲜有报道。本研究应用三代测序和微滴式数字PCR相结合的技术,以41对母婴志愿者胎粪、母亲粪便、羊水、产道液体、母乳和母亲唾液样品为研究对象,对母婴的菌群结构进行研究,旨在探索初生婴儿肠道菌群结构及其与母体各部位菌群的关联性。结果显示,所有志愿者胎粪、羊水、产道液体和母乳均以厚壁菌门与变形菌门为优势菌门,母亲粪便与唾液则以厚壁菌门和拟杆菌门为优势菌门,胎粪中变形菌门的相对含量显著高于母亲粪便,而拟杆菌门的相对含量则显著低于母亲粪便,在门的水平上显示出胎粪与羊水、产道液体和母乳的菌群结构更为相似,为婴儿肠道菌群在出生前已开始建立的学说提供新的证据。基于OTU水平的菌群相似性分析发现,胎粪和羊水、产道液体、母乳的菌群相似程度明显高于与其它母亲源样品,表明早期婴儿的肠道菌群结构与其分娩前的生存环境(羊水)和分娩过程中暂居环境(产道)中的菌群结构密切相关,胎儿可能会在子宫中通过吞咽羊水获得最初的母亲源微生物。研究发现,采用自然分娩的婴儿胎粪中乳杆菌多样性高于剖腹产分娩的婴儿。基于不同分娩方式的婴儿胎粪和产道液体菌群相似性分析显示,自然分娩的婴儿胎粪菌群与其母亲产道菌群的相似性显著高于剖腹产组(p0.001),表明新生儿在自然分娩过程中可能存在微生物接种的过程。微滴式数字PCR分析结果显示,乳杆菌属在自然分娩的婴儿胎粪中的绝对含量显著高于剖腹产分娩的婴儿(p0.01),说明选择不同分娩方式会对婴儿早期肠道中乳杆菌的定植造成一定的影响,这可能与自然分娩过程中婴儿接触了母亲产道,从而发生菌群传递有关。综上所述,母亲子宫内羊水环境中的微生物是胎儿最初获得的主要菌群,而不同的分娩方式也塑造了不同的婴儿肠道微生物特征。
[Abstract]:The human body is a "superorganism" made up of its own cells and microbiological cells. The early consensus was that the fetus's gut was sterile in the womb of the mother, with the increasing heat of related research. It has been found that the construction of fetal intestinal flora may have already begun in the mother, and that the microecological environment of the mother's gut, mouth, amniotic fluid, placenta, birth canal, mammary gland and skin may provide microbes for it. In this study, the technology of three-generation sequencing and microdrop digital PCR was used to study the meconium, mother's feces, amniotic fluid and birth canal fluid in 41 pairs of maternal and infant volunteers, including meconium, mother's feces, amniotic fluid, and birth canal fluid. The microflora structure of mother and infant was studied in breast milk and mother's saliva samples. The aim of this study was to explore the relationship between intestinal microflora structure and maternal flora of newborn infants. The results showed that all volunteers had meconium, amniotic fluid, amniotic fluid, meconium and amniotic fluid. The dominant phylum was phylum pachymatidis and phylum Proteus in the spawning fluid and breast milk, and the dominant phylum in feces and saliva of mother was phylum thuringiensis and phylum bacilli. The relative content of the phylum of Proteus in meconium was significantly higher than that in feces of mother. On the other hand, the relative content of Bacteroides was significantly lower than that of mother's feces, showing that meconium was more similar to amniotic fluid, fluid of birth canal and breast milk. To provide new evidence for the theory that the intestinal microflora had been established before birth. Based on the similarity analysis of OTU level, it was found that the similarity between meconium and amniotic fluid, fecal fluid and breast milk was significantly higher than that of other maternal samples. The results showed that the intestinal flora structure of early infants was closely related to the living environment (amniotic fluid) before delivery and the microflora structure in temporary living environment (birth canal) during delivery. The fetus may acquire the original maternal microbes in the womb by swallowing amniotic fluid. The diversity of Lactobacillus in meconium of natural delivery was higher than that in caesarean section. The similarity between meconium microflora and maternal faecal flora in natural delivery was significantly higher than that in caesarean section group (p 0.001), which indicated that the microorganism inoculation process might exist in the process of natural delivery. The results of microdrop digital PCR analysis showed that, The absolute content of Lactobacillus in the meconium of natural delivery was significantly higher than that in caesarean section, indicating that the selection of different delivery modes would have a certain effect on the colonization of Lactobacillus in the early intestine of infants. This may be related to the exposure of the infant to the mother's birth canal during natural delivery, which results in the transmission of bacteria. In summary, microbes in the mother's amniotic fluid environment are the primary flora of the fetus. Different delivery patterns also shape different intestinal microbiological characteristics of infants.
【学位授予单位】：内蒙古农业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R37

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