Wang X, Heazlewood S P, Krause D O, Florin T H J
UQ Department of Medicine Mater Hospital IBD Research Laboratory, Brisbane IBD Research Group, South Brisbane, QLD 4101, Australia.
J Appl Microbiol. 2003;95(3):508-20. doi: 10.1046/j.1365-2672.2003.02005.x.
The aim of this study was to characterize the bacterial community adhering to the mucosa of the terminal ileum, and proximal and distal colon of the human digestive tract.
Pinch samples of the terminal ileum, proximal and distal colon were taken from a healthy 35-year-old, and a 68-year-old subject with mild diverticulosis. The 16S rDNA genes were amplified using a low number of PCR cycles, cloned, and sequenced. In total, 361 sequences were obtained comprising 70 operational taxonomic units (OTU), with a calculated coverage of 82.6%. Twenty-three per cent of OTU were common to the terminal ileum, proximal colon and distal colon, but 14% OTU were only found in the terminal ileum, and 43% were only associated with the proximal or distal colon. The most frequently represented clones were from the Clostridium group XIVa (24.7%), and the Bacteroidetes (Cytophaga-Flavobacteria-Bacteroides) cluster (27.7%).
Comparison of 16S rDNA clone libraries of the hindgut across mammalian species confirms that the distribution of phylogenetic groups is similar irrespective of the host species. Lesser site-related differences within groups or clusters of organisms, are probable.
This study provides further evidence of the distribution of the bacteria on the mucosal surfaces of the human hindgut. Data contribute to the benchmarking of the microbial composition of the human digestive tract.
本研究旨在描述附着于人类消化道回肠末端、结肠近端和远端黏膜的细菌群落特征。
从一名35岁健康受试者以及一名患有轻度憩室病的68岁受试者身上采集回肠末端、结肠近端和远端的捏取样本。使用少量PCR循环扩增16S rDNA基因，进行克隆和测序。总共获得361个序列，包含70个操作分类单元（OTU），计算得出的覆盖率为82.6%。23%的OTU在回肠末端、结肠近端和远端均有出现，但14%的OTU仅在回肠末端发现，43%仅与结肠近端或远端相关。最常见的克隆来自梭菌属第十四a群（24.7%）和拟杆菌门（噬细胞-黄杆菌-拟杆菌）簇（27.7%）。
对不同哺乳动物物种后肠16S rDNA克隆文库的比较证实，无论宿主物种如何，系统发育类群的分布都是相似的。各生物类群或簇内与部位相关的差异可能较小。
本研究为人类后肠黏膜表面细菌的分布提供了进一步证据。数据有助于确定人类消化道微生物组成的基准。
