Bacterial biogeography of the human digestive tract

Department of Biology, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada.
Scientific Reports (Impact Factor: 5.58). 11/2011; 1:170. DOI: 10.1038/srep00170
Source: PubMed

ABSTRACT We present bacterial biogeography as sampled from the human gastrointestinal tract of four healthy subjects. This study generated >32 million paired-end sequences of bacterial 16S rRNA genes (V3 region) representing >95,000 unique operational taxonomic units (OTUs; 97% similarity clusters), with >99% Good's coverage for all samples. The highest OTU richness and phylogenetic diversity was found in the mouth samples. The microbial communities of multiple biopsy sites within the colon were highly similar within individuals and largely distinct from those in stool. Within an individual, OTU overlap among broad site definitions (mouth, stomach/duodenum, colon and stool) ranged from 32-110 OTUs, 25 of which were common to all individuals and included OTUs affiliated with Faecalibacterium prasnitzii and the TM7 phylum. This first comprehensive characterization of the abundant and rare microflora found along the healthy human digestive tract represents essential groundwork to investigate further how the human microbiome relates to health and disease.

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Available from: Dilani B Senadheera, Aug 27, 2015
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    • "The human large intestine is a dynamic microbial ecosystem inhabited by different bacterial species, which reach their highest concentrations in the colon (up to 10 12 cells per gram of feces) (Doré & Corthier, 2010). In adults, Bacteroidetes (including Bacteroides and Prevotella genera) and Firmicutes (including Clostridium, Enterococcus, Lactobacillus, Faecalibacterium and Ruminococcus genera) phyla predominated in colon mucosal sites, whereas proteobacteria, fusobacteria, actinobacteria, and verrucomicrobia are in considerably minor proportion (Qin et al., 2010; Stearns et al., 2011). Although the colonic microbiota is relatively stable throughout adult life, age-related changes in the gastrointestinal (GI) tract, inter-individual differences, as well as dietary factors and diverse disease conditions, inevitably affect population composition changing its microbial and metabolic profiles (Salonen & De Vos, 2014). "
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