title: Effect of predominant methanogenic flora on outcome of lactose hydrogen breath test in controls and irritable bowel syndrome patients of north India.
abstract: The relationship between methanogenic flora and hydrogen (H(2)) production is considered to be a possible confounding factor in the interpretation of hydrogen breath tests (H(2)BT). Therefore, the present study was conducted prospectively and included 154 IBS patients (fulfilling Rome II criteria) and 286 age-and-sex-matched apparently healthy controls. Each subject underwent H(2)BT after overnight fasting using 25 g lactose. Methane and H(2) were measured using an SC Microlyser from Quintron, USA, at baseline and every 30 min for a total of 4 h. Subjects with fasting methane concentration <10 ppm were labeled as low methane producers (LMP) and >10 ppm as predominant methane producers (PMP). A rise >20 ppm over base line in hydrogen concentration was taken as +ve hydrogen breath test. IBS and control groups included 66.78% and 67.53% males, respectively. Mean age in the two groups were 48.52 +/- 30.54 years (range 15-68 years) and 45.67 +/- 30.54 years (range 15-78 years), respectively. Hydrogen breath test was +ve in 77/154 (50%) IBS patients and in 142/286 (49.65%) in controls (P > 0.05). It was also observed that the hydrogen breath test was -ve due to PMP in 5/77 (6.49%) of IBS patients and in 29/154 (20.14%) in controls. PMP affected lactose hydrogen breath tests in 6.49-20.14% subjects. This effect is more apparent in apparently healthy subjects as compared to patients with IBS.
authors.affiliation: Department of Gastroenterology, Postgraduate Institute of Medical Education and Research, Chandigarh, 160012, India. svrana25@hotmail.com
authors.forename: S V
authors.initials: SV
authors.lastname: Rana
authors.forename: S K
authors.initials: SK
authors.lastname: Sinha
authors.forename: S
authors.initials: S
authors.lastname: Sharma
authors.forename: H
authors.initials: H
authors.lastname: Kaur
authors.forename: D K
authors.initials: DK
authors.lastname: Bhasin
authors.forename: K
authors.initials: K
authors.lastname: Singh
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001421:Bacteria, Anaerobic / Q000254:growth & development / Q000378:metabolism; D001944:Breath Tests; D015986:Confounding Factors, Epidemiologic; D005260:Female; D006801:Humans; D007194:India; D043183:Irritable Bowel Syndrome / Q000175:diagnosis* / Q000378:metabolism / Q000382:microbiology; D007792:Lactulose; D008297:Male; D008697:Methane / Q000096:biosynthesis; D008875:Middle Aged; D055815:Young Adult
chemical_list: D007792:Lactulose; D008697:Methane