Department of Biochemistry and Molecular Biology, Wright State University, Dayton, Ohio, USA.
Am J Gastroenterol. 2012 Nov;107(11):1740-51. doi: 10.1038/ajg.2012.287.
Human intestinal microbiota has a number of important roles in human health and is also implicated in several gastrointestinal disorders. The goal of this study was to determine the gut microbiota in two groups of pre- and adolescent children: healthy volunteers and children diagnosed with diarrhea predominant irritable bowel syndrome (IBS-D).
Phylogenetic Microbiota Array was used to obtain quantitative measurements of bacterial presence and abundance in subjects ’ fecal samples. We utilized high-throughput DNA sequencing, quantitative PCR, and fluorescent in situ hybridization to confirm microarray findings.
Both sample groups were dominated by the phyla Firmicutes, Bacteroidetes, and Actinobacteria, which cumulatively constituted 91 % of overall sample composition on average. A core microbiome shared among analyzed samples encompassed 55 bacterial phylotypes dominated by genus Ruminococcus ; members of genera Clostridium , Faecalibacterium, Roseburia, Streptococcus , and Bacteroides were also present. Several genera were found to be differentially abundant in the gut of healthy and IBS groups: levels of Veillonella , Prevotella , Lactobacillus , and Parasporo bacterium were increased in children diagnosed with IBS, whereas members of Bifidobacterium and Verrucomicrobium were less abundant in those individuals. By calculating a nonparametric correlation matrix among abundances of different genera in all samples, we also examined potential associations among intestinal microbes. Strong positive correlations were found between abundances of Veillonella and both Haemophilus and Streptococcus , between Anaerovorax and Verrucomicrobium , and between Tannerella and Anaerophaga .
Although at the higher taxonomical level gut microbiota was similar between healthy and IBS-D children, specific differences in the abundances of several bacterial genera were revealed. Core microbiome in children was dominated by Clostridia. Putative relationships identified among microbial genera provide testable hypotheses of cross-species associations among members of human gut microbiota
人类肠道微生物群在人类健康中具有许多重要作用，也与几种胃肠道疾病有关。本研究的目的是确定两组儿童的肠道微生物群：健康志愿者和被诊断为腹泻型肠易激综合征（IBS-D）的儿童。
采用系统发育微生物阵列获得受试者粪便样本中细菌存在和丰度的定量测量值。我们利用高通量 DNA 测序、定量 PCR 和荧光原位杂交来验证微阵列的发现。
两组样本均以厚壁菌门、拟杆菌门和放线菌门为主，平均累积构成样本组成的 91%。分析样本中共享的核心微生物组包含 55 个细菌类群，以瘤胃球菌属为主；也存在梭菌属、粪杆菌属、罗斯伯里氏菌属、链球菌属和拟杆菌属的成员。在健康组和 IBS 组的肠道中发现了几种丰度差异较大的属：肠球菌属、普雷沃氏菌属、乳杆菌属和副拟杆菌属的水平在被诊断为 IBS 的儿童中增加，而双歧杆菌属和韦荣球菌属的成员在这些个体中较少。通过计算所有样本中不同属丰度的非参数相关矩阵，我们还研究了肠道微生物之间的潜在关联。在所有样本中，发现韦荣球菌属与嗜血杆菌属和链球菌属之间、厌氧梭菌属与韦荣球菌属之间以及丹纳氏菌属与厌氧拟杆菌属之间存在强烈的正相关关系。
尽管在较高的分类水平上，健康和 IBS-D 儿童的肠道微生物群相似，但揭示了几种细菌属丰度的具体差异。儿童的核心微生物群以梭菌属为主。鉴定出的微生物属之间的假定关系提供了可检验的人类肠道微生物群成员之间的种间关联假说。
