title: Sulphate-reducing bacteria and hydrogen sulphide in the aetiology of ulcerative colitis.
abstract: BACKGROUND
  The aetiology of ulcerative colitis is uncertain but may relate to environmental factors in genetically predisposed individuals. Sulphate-reducing bacteria (SRB) have been implicated through the harmful effects of hydrogen sulphide, a by-product of their respiration. Hydrogen sulphide is freely permeable to cell membranes and inhibits butyrate. This review examines the available evidence relating to SRB as a possible cause of ulcerative colitis.
  
  
  METHODS
  A literature search was conducted using the PubMed database and search terms 'sulphate reducing bacteria', 'hydrogen sulphide', 'ulcerative colitis', 'mucous gel layer' and 'trans-sulphuration'.
  
  
  RESULTS
  Search results were scrutinized and 113 pertinent full-text articles were selected for review. Collected data related to hydrogen sulphide metabolism, SRB respiration, mucous gel layer composition and their association with ulcerative colitis.
  
  
  CONCLUSIONS
  There is evidence to implicate SRB as an environmental factor in ulcerative colitis. More sophisticated mucosal dissection and molecular techniques using bacteria-directed probes are required to determine an association definitively.
authors.affiliation: School of Medicine and Medical Sciences, University College Dublin, Dublin, Ireland.
authors.forename: F E
authors.initials: FE
authors.lastname: Rowan
authors.forename: N G
authors.initials: NG
authors.lastname: Docherty
authors.forename: J C
authors.initials: JC
authors.lastname: Coffey
authors.forename: P R
authors.initials: PR
authors.lastname: O'Connell
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D003093:Colitis, Ulcerative / Q000209:etiology* / Q000382:microbiology; D005978:Glutathione / Q000502:physiology; D016905:Gram-Negative Bacterial Infections; D006801:Humans; D006862:Hydrogen Sulfide / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000382:microbiology; D016999:Sulfur-Reducing Bacteria / Q000378:metabolism*; D013884:Thiosulfate Sulfurtransferase / Q000378:metabolism
chemical_list: D000596:Amino Acids; D013884:Thiosulfate Sulfurtransferase; D005978:Glutathione; D006862:Hydrogen Sulfide