Breath methane in functional constipation: response to treatment with Ispaghula husk

• Published in: Neurogastroenterology and motility Vol. 27; no. 7; pp. 945 - 953
• Main Authors: Vega, A. B., Perelló, A., Martos, L., García Bayo, I., García, M., Andreu, V., Abad, A., Barenys, M.
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.07.2015
• Subjects: Adult; Breath Tests; Cathartics - pharmacology; Cathartics - therapeutic use; Colon - drug effects; Colon - physiopathology; colonic transit time; Constipation - drug therapy; Constipation - physiopathology; Female; functional constipation; Gastrointestinal Transit - drug effects; Gastrointestinal Transit - physiology; Humans; Ispaghula husk; lactulose breath test; Male; Methane - analysis; methane producer; Middle Aged; Psyllium - pharmacology; Psyllium - therapeutic use; Treatment Outcome; functional constipation; methane producer; lactulose breath test; colonic transit time; Ispaghula husk
• ISSN: 1350-1925; 1365-2982; 1365-2982
• DOI: 10.1111/nmo.12568

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. Key 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 & Inferences 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. Colonic fermentation of undigested carbohydrates produces hydrogen, and also produces methane in subjects with methanogenic flora. The production of both gases can be measured indirectly by breath testing. Methane breath production is associated to chronic constipation and the amount of this gas has been shown to inversely correlate with the average number of bowel movements per day and colonic transit speed. The pathophysiological mechanism is being under investigation with the significative finding in animal models that methane could slow intestinal transit. Treatment with fiber as Ispaghula husk is a widely used first‐line treatment in primary care, and as a substrate for anaerobic fermentation, may increase methane production in methanogenic subjects having a deleterious effect on constipation. This is the first study measuring changes in methane production under fiber treatment. However, in this study methane status or quantitative production did not negatively affect the response to Ispaghula husk treatment in functional chronic constipation.