title: A combined 13CO2/H2 breath test can be used to assess starch digestion and fermentation in humans.
abstract: Ingestion of starch from corn (naturally enriched with (13)C) should produce (13)CO(2) after small intestinal digestion and (13)CO(2) and H(2) from colonic fermentation. This study used a combined (13)CO(2)/H(2) breath test to assess the digestion and fermentation of resistant starch and to show that the test could detect changes in digestibility due to cooking. Volunteers consumed 40 g digestible cornstarch with water (n = 8), or 40 g resistant cornstarch in liquid (n = 12) or cooked into a pancake (n = 4). Interval breath sampling was performed and analyzed for (13)CO(2) and H(2). Ingestion of resistant starch produced a double-peaked (13)CO(2) excretion curve. The first increase in (13)CO(2) occurred at the same time as excretion from digestible starch (55 +/- 9 and 68 +/- 9 min, respectively), which was due to small intestinal digestion. The second increase in (13)CO(2) was accompanied by an increase in H(2) excretion (432 +/- 15 and 428 +/- 48 min, respectively), which was indicative of colonic bacterial fermentation. Cooking resistant starch increased its degree of digestion from 36 to 72%. The (13)CO(2)/H(2) breath test can be used to estimate digestion and fermentation of starches in different physiologic and pathologic conditions.
authors.affiliation: Gastroenterology Unit, Women's and Children's Hospital, North Adelaide, and Department of Physiology, University of Adelaide, Adelaide, South Australia. erinsymonds@yahoo.com
authors.forename: Erin L
authors.initials: EL
authors.lastname: Symonds
authors.forename: Stamatiki
authors.initials: S
authors.lastname: Kritas
authors.forename: Taher I
authors.initials: TI
authors.lastname: Omari
authors.forename: Ross N
authors.initials: RN
authors.lastname: Butler
mesh_terms: D000328:Adult; D001944:Breath Tests; D002245:Carbon Dioxide; D002247:Carbon Isotopes; D003296:Cooking; D004063:Digestion; D005260:Female; D005285:Fermentation; D006801:Humans; D006859:Hydrogen; D013213:Starch / Q000378:metabolism*
chemical_list: D002247:Carbon Isotopes; D002245:Carbon Dioxide; D006859:Hydrogen; D013213:Starch