Dose dependence of breath hydrogen and methane in healthy volunteers after ingestion of a commercial disaccharide mixture, Palatinit

Abstract

Breath hydrogen and methane were determined by gas chromatography in eleven normal individuals given a low-fibre, mixed diet (control) and after ingestion of 20-50 g Palatinit/d, an equimolar mixture of D-glucosyl-alpha(1----1)-D-mannitol and D-glucosyl-alpha(1----6)-D-glucitol (Isomalt). A linear relation was found (r 0.85; P less than 0.001) between the amount of Palatinit ingested and breath H2 per 10 h in subjects who did not exhale methane. If methane was formed in addition to H2, the sum of both gases followed a linear dose-effect relation. The mouth-to-caecum time, indicated by the first increase in breath H2 after ingestion, was shortened by about half, yet no sign of diarrhoea was observed. Stool weight and stool frequency did not change significantly. The linear relation between a dose of 20-50 g Palatinit and exhalation of H2 (eventually plus methane) indicated that a relatively constant fraction of the dose given underwent cleavage and absorption in the small intestine, the remainder being transported into the large bowel. Microbial gas formation in the colon as well as the fractional transfer of these gases into the expiratory air occurred at fixed proportions, thus allowing an insight into colonic microbial contributions to carbohydrate utilization in the human large bowel.