Metabolism of dietary fibre components in man assessed by breath hydrogen and methane.

1. Breath hydrogen and methane were measured in eight normal individuals after acute and separate administration of different chemical components of dietary fibre. 2. Hemicellulose, raffinose and lactulose increased H2 production, while cellulose pectin and lignin did not. Methane production was found to be individual and unaffected by any of the substances. Differences in physical properties of the same chemical appear to have no influences on H2 and CH4 production.