title: Distinct microbiome in pouchitis compared to healthy pouches in ulcerative colitis and familial adenomatous polyposis.
abstract: BACKGROUND
  Pouchitis occurs in up to 50% of patients with ulcerative colitis (UC) undergoing ileal pouch anal anastomosis (IPAA). Pouchitis rarely occurs in patients with familial adenomatous polyposis (FAP) who undergo IPAA. Our aim was to compare mucosal and luminal flora in patients with UC-associated pouchitis (UCP), healthy UC pouches (HUC), and healthy FAP pouches (FAP).
  
  
  METHODS
  Nineteen patients were enrolled in this cross-sectional study (nine UCP, three HUC, seven FAP). Patients with active pouchitis were identified using the Pouchitis Disease Activity Index (PDAI). Ileal pouch mucosal biopsies and fecal samples were analyzed with a 16S rDNA-based terminal restriction fragment length polymorphism (TRFLP) approach. Pooled fecal DNA from four UCP and four FAP pouches were sequenced for further speciation.
  
  
  RESULTS
  TRFLP data revealed statistically significant differences in the mucosal and fecal microbiota between each group of patients. UCP samples exhibited significantly more TRFLP peaks matching Clostridium and Eubacterium genera compared to HUC and FAP pouches and fewer peaks matching Lactobacillus and Streptococcus genera compared to FAP. DNA Sanger sequencing of a subset of luminal samples revealed UCP having more identifiable sequences of Firmicutes (51.2% versus 21.2%) and Verrucomicrobia (20.2% versus 3.2%), and fewer Bacteroidetes (17.9% versus 60.5%) and Proteobacteria (9.8% versus 14.7%) compared to FAP.
  
  
  CONCLUSIONS
  The pouch microbial environment appears to be distinctly different in the settings of UC pouchitis, healthy UC, and FAP. These findings suggest that a dysbiosis may exist in pouchitis which may be central to understanding the disease.
authors.affiliation: Division of Pediatric Gastroenterology, Department of Pediatrics, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA. gzella@partners.org
authors.forename: Garrett C
authors.initials: GC
authors.lastname: Zella
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Hait
authors.forename: Tiffany
authors.initials: T
authors.lastname: Glavan
authors.forename: Dirk
authors.initials: D
authors.lastname: Gevers
authors.forename: Doyle V
authors.initials: DV
authors.lastname: Ward
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Kitts
authors.forename: Joshua R
authors.initials: JR
authors.lastname: Korzenik
mesh_terms: D039903:Actinobacteria / Q000235:genetics / Q000302:isolation & purification; D011125:Adenomatous Polyposis Coli / Q000382:microbiology* / Q000601:surgery*; D000328:Adult; D001439:Bacteroides / Q000235:genetics / Q000302:isolation & purification; D001706:Biopsy; D003093:Colitis, Ulcerative / Q000382:microbiology* / Q000601:surgery*; D004269:DNA, Bacterial / Q000032:analysis; D005243:Feces / Q000382:microbiology; D005260:Female; D045182:Fusobacteria / Q000235:genetics / Q000302:isolation & purification; D041981:Gastrointestinal Tract / Q000382:microbiology; D006801:Humans; D008297:Male; D054892:Metagenome; D008875:Middle Aged; D011183:Postoperative Complications / Q000382:microbiology / Q000473:pathology; D019449:Pouchitis / Q000382:microbiology* / Q000473:pathology; D020560:Proteobacteria / Q000235:genetics / Q000302:isolation & purification; D055815:Young Adult
chemical_list: D004269:DNA, Bacterial