Comparative flatulence activity of beans and bean fractions for man and the rat.

To evaluate H2 production in the rat after ingestion of legume products as a predictive bioassay of their flatulence activity for man, responses of man and the rat to (1) a bland formula diet, (2) cooked California Small White bean (CSW) solids, (3) 70% ethanol extract of (2), (4) oligosaccharide fraction of (3), (5) non-protein nitrogen fraction of (3), and (6) combination of (4) and (5) were compared. Six human subjects were fed an 800 kcal breakfast of (1) or containing the amount of a test item equivalent to 100 g CSW. Each subject received all items once plus a single replicate of three items at the rate of one per week in random order. Total flatus volume, H2, CO2, and CH4 volumes and breath H2 concentration were measured for the interval 2.5 to 8.5 hours after breakfast. Young rats in metabolic chambers received known amounts of items 2 to 6 mixed with a bland basal diet. H2 trapped in the chambers was measured after 20 hours. Correlation of rat H2 and to human breath H2 measurements and flatus gas volumes were significant and positive except for negative correlation with flatus methane volume. Measurement of hydrogen production in the rat has potential for a predictive bioassay for flatulence in man.