A randomised trial of sheathed versus standard forceps for obtaining uncontaminated biopsy specimens of microbiota from the terminal ileum

• Published in: Gut Vol. 60; no. 8; pp. 1043 - 1049
• Main Authors: Dave, Maneesh, Johnson, Laura A, Walk, Seth T, Young, Vincent B, Stidham, Ryan W, Chaudhary, Meghana N, FunNell, Jessica, Higgins, Peter D R
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group Ltd and British Society of Gastroenterology 01.08.2011; BMJ Publishing Group; BMJ Publishing Group LTD
• Subjects: Antibiotics; Bacteria; Bacteria - genetics; Biological and medical sciences; Biopsy; Biopsy - instrumentation; Bowel disease; Colleges & universities; Colonoscopes; Colonoscopy; Crohn's disease; DNA, Bacterial - analysis; endoscopic procedures; Feces; Gastroenterology. Liver. Pancreas. Abdomen; Gut microbiota; Humans; Ileum - cytology; Ileum - microbiology; inflammatory bowel disease; intestinal microbiology; Medical sciences; Metagenome; Methods; microbial diversity; microbiota; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; Prospective Studies; Reproducibility of Results; Surgical Instruments - standards; terminal ileum; terminal restriction fragment length polymorphism; Biopsy; Forceps; Ileum; Comparative study; Gastroenterology
• ISSN: 0017-5749; 1468-3288; 1468-3288
• DOI: 10.1136/gut.2010.224337

BackgroundThe study of intestinal microbiota has been revolutionised by the use of molecular methods, including terminal restriction fragment length polymorphism (T-RFLP) analysis. Microbiota studies of Crohn's disease patients have examined samples from stool or from the neoterminal ileum with a standard biopsy forceps, which could be contaminated by colonic bacteria when the forceps passes through the colonoscope channel.ObjectiveTo determine whether sheathed biopsy forceps are able to obtain terminal ileal microbiota samples with less colonic bacterial contamination compared with unsheathed (standard) biopsy forceps.DesignProspective randomised single-centre study.Patients and methodsFour (paired) biopsy specimens were obtained from adjacent locations in the terminal ileum using the sheathed and standard forceps of 27 consecutive subjects undergoing colonoscopy and the microbiota were characterised using T-RFLP. The Bray–Curtis similarity index between samples (sheathed vs unsheathed forceps) was calculated within patients and significant differences were tested for across all patients.ResultsThere was not a significant difference in the microbial diversity of samples obtained using sheathed versus unsheathed forceps. The difference in microbial diversity between patients was much greater than the variability within patients by proximal versus distal site or by forceps type.LimitationsT-RFLP is based on PCR amplification, so it is not always sensitive to rare bacterial species.ConclusionStandard unsheathed forceps appear to be sufficient for microbiota sample collection from the terminal ileum.