title: Oesophageal bacterial biofilm changes in gastro-oesophageal reflux disease, Barrett's and oesophageal carcinoma: association or causality?
abstract: CONCLUSIONS
  Barrett's oesophagus (BO) and gastro-oesophageal reflux disease (GERD) are precursors of oesophageal adenocarcinoma (OAC). There is an oesophageal biofilm, which changes in disease, but its role in aetiopathogenesis remains unclear.
  
  
  OBJECTIVE
  To define the oesophageal microbiota of patients with GERD, BO and OAC compared with controls and to investigate mucosal responses related to the microbiota.
  
  
  METHODS
  Cultural analysis identified the dominant bacterial species from a subset of each disease group. Based on this, molecular techniques were used to define the cohort. Host responses were analysed in tissues and co-culture experiments.
  
  
  RESULTS
  A total of 111 species belonging to 26 genera were isolated. There was a significant decrease in bacterial counts in the GERD and BO groups for all genera except Campylobacter, which colonised GERD and Barrett's patients in increasing numbers. Campylobacter concisus was the dominant species. This relationship was not seen in the cancer group. Significant increases in IL-18 were seen in GERD and BO colonised by Campylobacter.
  
  
  CONCLUSIONS
  This study defines differences in the oesophageal biofilm in disease states, revealing the emergence of C. concisus as the dominant new colonist in the refluxed oesophagus. We also associate the presence of these bacteria with increased expression of cytokines related to carcinogenesis.
authors.affiliation: Gut Group, Biomedical Research Institute, University of Dundee, Dundee, UK.
authors.forename: K L
authors.initials: KL
authors.lastname: Blackett
authors.forename: S S
authors.initials: SS
authors.lastname: Siddhi
authors.forename: S
authors.initials: S
authors.lastname: Cleary
authors.forename: H
authors.initials: H
authors.lastname: Steed
authors.forename: M H
authors.initials: MH
authors.lastname: Miller
authors.forename: S
authors.initials: S
authors.lastname: Macfarlane
authors.forename: G T
authors.initials: GT
authors.lastname: Macfarlane
authors.forename: J F
authors.initials: JF
authors.lastname: Dillon
mesh_terms: D000230:Adenocarcinoma / Q000382:microbiology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018407:Bacterial Physiological Phenomena; D001471:Barrett Esophagus / Q000382:microbiology*; D018441:Biofilms / Q000254:growth & development*; D016022:Case-Control Studies; D018920:Coculture Techniques; D015331:Cohort Studies; D015169:Colony Count, Microbial; D016207:Cytokines / Q000235:genetics; D004938:Esophageal Neoplasms / Q000382:microbiology*; D004947:Esophagus / Q000382:microbiology; D005260:Female; D005764:Gastroesophageal Reflux / Q000382:microbiology*; D006801:Humans; D008297:Male; D054892:Metagenome; D008875:Middle Aged; D012333:RNA, Messenger / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D055815:Young Adult
chemical_list: D016207:Cytokines; D012333:RNA, Messenger