THE POSSIBLE ROLE OF BREATH METHANE MEASUREMENT IN DETECTING CARBOHYDRATE MALABSORPTION

To evaluate the possibility that measurement of breath methane (CH4) e nhances the accuracy of breath hydrogen (H-2) testing to diagnose carb ohydrate malabsorption, breath CH4 concentration of healthy subjects w as studied. Fasting breath CH4 concentration measured three times over a 30-minute period in 44 CH4-producing volunteers ranged from 5 to 12 0 ppm. Fluctuation of breath CH4 excretion exceeded 100% increase over tasting in 1 of 9 subjects who ingested a nonabsorbable, carbohydrate -free solution. Out of 13 subjects who had a false negative breath H-2 response to lactulose, 11 had a CH4 percentage increase greater than 100%. In 11 of 32 lactose-intolerant patients with a negative breath H -2 test, CH4 percentage increase after lactose challenge was greater t han 100%. These data suggested that in methanogenic individuals, breat h CH4 measurement might enhance the accuracy of H-2 breath testing in detecting carbohydrate malabsorption.