title: Breath methane in functional constipation: response to treatment with Ispaghula husk.
abstract: BACKGROUND
  Colonic fermentation produces hydrogen (H2 ), and also produces methane (CH4 ) in subjects with methanogenic flora (M+). Methane production has been associated with chronic constipation (CC) and with changes in gut motility. To determine CH4 production in CC compared to controls, and to assess whether the therapeutic response to Ispaghula husk in CC differs between CH4 -producers and non-producers.
  
  
  METHODS
  Forty-eight patients with functional constipation or irritable bowel syndrome-constipation and 19 healthy age-and-sex-matched volunteers (HV) filled in a 1-week symptom diary and a dietary questionnaire. They then underwent a lactulose breath test (LBT) to measure H2 and CH4 production (peak and area under the time-concentration curve, AUC-) and a colonic transit time (CTT) assessment. In patients, measurements were repeated after a 4-week treatment with Ispaghula husk.
  
  
  RESULTS
  Prevalence of M+ in patients was 60.5% vs 52.6% in HV (p = 0.37). Patients had significantly longer CTT and greater production of both H2 and CH4 during LBT. There was a significant correlation between CH4 production and CTT (r = 0.51; p = 0.07). Treatment response rate was similar for M+ and M- patients (58.3% vs 52.9%; p = 0.76) as were the increases in bowel movements and Bristol score, changes in abdominal discomfort and bloating. In M+, treatment reduced CTT (-10 ± 35 h; p = 0.029 vs baseline) and CH4 levels: peak CH4 (-13 ± 24 ppm; p = 0.014) and CH4 -AUC (-817 ± 3100 ppm/min; p = 0.04).
  
  
  CONCLUSIONS
  Although CH4 production has been associated with CC pathophysiology, we found that CH4 status did not negatively affect the response to Ispaghula husk treatment. The measurement of CH4 levels as a biomarker tool for CC requires further appraisal.
authors.affiliation: Hospital Duran i Reynals, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Barcelona University, Barcelona, Spain.
authors.forename: A B
authors.initials: AB
authors.lastname: Vega
authors.affiliation: Gastroenterology Department, Hospital de Viladecans, Barcelona, Spain.|Hospital Duran i Reynals, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Barcelona University, Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Perelló
authors.affiliation: Gastroenterology Department, Hospital de Viladecans, Barcelona, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Martos
authors.affiliation: Primary Care Center Gavà II, Barcelona, Spain.
authors.forename: I
authors.initials: I
authors.lastname: García Bayo
authors.affiliation: Gastroenterology Department, Hospital de Viladecans, Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: García
authors.affiliation: Gastroenterology Department, Hospital de Viladecans, Barcelona, Spain.|Hospital Duran i Reynals, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Barcelona University, Barcelona, Spain.
authors.forename: V
authors.initials: V
authors.lastname: Andreu
authors.affiliation: Gastroenterology Department, Hospital de Viladecans, Barcelona, Spain.|Hospital Duran i Reynals, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Barcelona University, Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Abad
authors.affiliation: Gastroenterology Department, Hospital de Viladecans, Barcelona, Spain.|Hospital Duran i Reynals, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Barcelona University, Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Barenys
mesh_terms: D000328:Adult; D001944:Breath Tests; D002400:Cathartics / Q000494:pharmacology / Q000627:therapeutic use*; D003106:Colon / Q000187:drug effects* / Q000503:physiopathology; D003248:Constipation / Q000188:drug therapy / Q000503:physiopathology; D005260:Female; D005772:Gastrointestinal Transit / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D008297:Male; D008697:Methane / Q000032:analysis*; D008875:Middle Aged; D011620:Psyllium / Q000494:pharmacology / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D002400:Cathartics; D011620:Psyllium; D008697:Methane
keywords: Ispaghula husk; colonic transit time; functional constipation; lactulose breath test; methane producer