Objective: To test the effect of the concomitant ingestion of glucose or lipids on sorbitol absorption in the human small intestine using the hydrogen breath test.
Method: After an overnight fast, on four occasions separated by at least 1 week 14 healthy volunteers randomly ingested 20 g sorbitol alone, 20 g sorbitol and 20 g glucose, 20 g sorbitol and 9 g lipids, and 10 g lactulose. Hydrogen concentration was measured in end-expiratory samples every 10 min for 3 h, and then every 30 min for 5 h. Sorbitol malabsorption was calculated from the ratio of the areas under the curve.
Results: The estimated rate of sorbitol malabsorption was 98 +/- 14% (mean +/- SEM) when sorbitol was ingested alone, and was significantly lower when ingested with glucose or lipids (68 +/- 10 and 70 +/- 7%, respectively; P < 0.05). Orocaecal transit times did not differ significantly between the different time periods.
Conclusion: Sorbitol absorption in the human small intestine is increased by the concomitant ingestion of glucose or lipids.