Reduced ¹³C-D-xylose absorption in alcoholics is more likely caused by alterations in small intestinal mucosa than delayed gastric emptying

Alterations of the small intestinal absorptive surface are a probable cause of D-xylose malabsorption in chronic alcoholism. Delayed gastric emptying, however, may influence the (13)C-D-xylose breath test, which is used to study intestinal function in alcoholics. The aim of this study was to measure gastric emptying in alcoholics to elucidate whether retention of the test meal could explain the malabsorptive pattern of the (13)C-D-xylose breath test observed in alcoholics.Fifteen alcoholics performed the (13)C-octanoic acid and the (13)C-D-xylose breath tests on consecutive days in a random order. The (13)CO(2) expired was measured every 30 or 15 min for 4 h in the (13)C-D-xylose and the (13)C-octanoic acid breath tests, respectively, using a mass spectrometer equipped with a gas chromatograph. Test meals consisted of 100 mg of (13)C-D-xylose and 5 g of unmarked D-xylose dissolved in 250 ml water and 91 mg (13)C-octanoic acid embedded in a one-egg omelette served with white bread with margarine, respectively.The alcoholic patients had a lower (13)C-D-xylose breath index compared with healthy controls (p0.0001). None of the (13)C-octanoic acid breath test variables, T(50%), T(max), T(lag), or GEC revealed any significant differences between the groups.The pathological (13)C-D-xylose breath test in this group of alcoholics is unlikely to be caused by delayed gastric emptying. Malabsorption is the probable cause of the pathological (13)C-D-xylose breath test results in alcoholics.