title: Culture-independent analysis of the gut microbiota in colorectal cancer and polyposis.
abstract: A role for the intestinal microbiota is routinely cited as a potential aetiological factor in colorectal cancer initiation and progression. As the majority of bacteria in the gut are refractory to culture we investigated this ecosystem in subjects with colorectal cancer and with adenomatous polyposis who are at high risk of developing colorectal cancer, using culture-independent methods. Twenty colorectal cancer and 20 polypectomized volunteers were chosen for this analysis. An exploration of the diversity and temporal stability of the dominant bacteria and several bacterial subgroups was undertaken using 16S rRNA gene denaturing gradient gel electrophoresis and ribosomal intergenic spacer analysis (RISA). Metabonomic analysis of the distal gut microbiota's environment was also undertaken. A significantly reduced temporal stability and increased diversity for the microbiota of subjects with colorectal cancer and polyposis was evident. A significantly increased diversity of the Clostridium leptum and C. coccoides subgroups was also noted for both disease groups. A clear division in the metabonome was observed for the colorectal cancer and polypectomized subjects compared with control volunteers. The intestinal microbiota and their metabolites are significantly altered in both colorectal cancer and polypectomized subjects compared with controls.
authors.affiliation: Department of Microbiology, University College Cork, Cork, Ireland.
authors.forename: Pauline D
authors.initials: PD
authors.lastname: Scanlan
authors.forename: Fergus
authors.initials: F
authors.lastname: Shanahan
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Clune
authors.forename: John K
authors.initials: JK
authors.lastname: Collins
authors.forename: Gerald C
authors.initials: GC
authors.lastname: O'Sullivan
authors.forename: Micheal
authors.initials: M
authors.lastname: O'Riordan
authors.forename: Elaine
authors.initials: E
authors.lastname: Holmes
authors.forename: Yulan
authors.initials: Y
authors.lastname: Wang
authors.forename: Julian R
authors.initials: JR
authors.lastname: Marchesi
mesh_terms: D011125:Adenomatous Polyposis Coli / Q000382:microbiology*; D044822:Biodiversity; D003013:Clostridium / Q000145:classification / Q000235:genetics; D015179:Colorectal Neoplasms / Q000382:microbiology*; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000032:analysis*; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D041981:Gastrointestinal Tract; D006801:Humans; D007422:Intestines / Q000382:microbiology*; D008297:Male; D012336:RNA, Ribosomal, 16S / Q000032:analysis* / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D021903:DNA, Ribosomal Spacer; D012336:RNA, Ribosomal, 16S