title: Influence of a methanogenic flora on the breath H2 and symptom response to ingestion of sorbitol or oat fiber.
abstract: OBJECTIVE
  We investigated the possibility that a variant of the normal colonic flora, a high concentration of methanogens, influences the host's response to ingestion of nonabsorbable, fermentable materials.
  
  
  METHODS
  To better evaluate symptomatic and breath H2 and methane (CH4) responses, subjects were placed on a basal diet (primarily rice and hamburger) that contained minimal amounts of nonabsorbable, fermentable substrate. A breath CH4/H2 ratio of greater or less than 1 on the second day of the basal diet was used to categorize subjects as high (N = 9) or low (N = 25) CH4 producers. After stabilization of the breath gas excretion (day 3 or 4 on the basal diet), the subjects ingested either sorbitol (8.8 g) or oat fiber (10.2 g).
  
  
  RESULTS
  The low CH4 producers had a significantly higher (p < 0.05) breath H2 concentration than the high producers on the basal diet and after ingestion of sorbitol (27.1 +/- 2.7 ppm vs 15.8 +/- 3.6 ppm) or oat fiber (13.1 +/- 0.08 ppm vs 9.6 +/- 1.2 ppm). Low producers of methane reported significantly increased bloating and cramping after sorbitol ingestion and increased bloating after fiber ingestion, whereas high CH4 producers reported no significant increase in these symptoms.
  
  
  CONCLUSIONS
  The presence of a methanogenic flora is associated with a reduced symptomatic response to ingestion of nonabsorbable, fermentable material in healthy subjects. Manipulation of the normal flora could be of therapeutic value in nonmethanogenic patients with irritable bowel syndrome.
authors.affiliation: Procter and Gamble Company, Cincinnati, Ohio, USA.
authors.forename: T M
authors.initials: TM
authors.lastname: Kajs
authors.forename: J A
authors.initials: JA
authors.lastname: Fitzgerald
authors.forename: R Y
authors.initials: RY
authors.lastname: Buckner
authors.forename: G A
authors.initials: GA
authors.lastname: Coyle
authors.forename: B S
authors.initials: BS
authors.lastname: Stinson
authors.forename: J G
authors.initials: JG
authors.lastname: Morel
authors.forename: M D
authors.initials: MD
authors.lastname: Levitt
mesh_terms: D018554:Avena; D001944:Breath Tests; D004032:Diet / Q000009:adverse effects; D015930:Diet Records; D004043:Dietary Fiber / Q000494:pharmacology*; D019605:Euryarchaeota / Q000378:metabolism*; D005414:Flatulence / Q000209:etiology; D006801:Humans; D006859:Hydrogen / Q000032:analysis / Q000378:metabolism*; D007422:Intestines / Q000382:microbiology*; D013012:Sorbitol / Q000494:pharmacology*
chemical_list: D004043:Dietary Fiber; D013012:Sorbitol; D006859:Hydrogen