BREATH HYDROGEN AND METHANE IN POPULATIONS AT DIFFERENT RISK FOR COLON-CANCER

Results from laboratory and clinical studies have suggested that ferme ntation in the large bowel may play a protective role against colon ca ncer. Hydrogen and methane are end-products of colonic fermentation th at are absorbed into the bloodstream and excreted via expired air in t he breath. Thus, breath levels of hydrogen and methane have been used as markers for this process. Breath levels of these gases were compare d among 10 ethnic and sex groups that exhibit marked differences for c olon cancer risk in Hawaii. Four end-expiratory breath samples were us ed to characterize daily excretion of hydrogen and methane in a popula tion-based sample of 244 men and women. There was no significant diffe rence in breath hydrogen or methane by sex or age. Hawaiians produced significantly more hydrogen than Filipinos, and Hawaiians and Caucasia ns more methane than the 3 Asian groups. These differences did not cor relate with risk of colon cancer among these ethnic populations. (C) 1 993 Wiley-Liss, Inc.