Follow-up of celiac disease with D-xylose breath test.

Hydrogen breath tests (H2-BT) are commonly used to diagnose carbohydrate malabsorption. Specifically, the H2-BT with D-xylose has been shown to be as valid as the traditional urinary test for the recognition of intestinal malabsorption. We have now investigated the H2-BT with D-xylose in the follow-up of patients with celiac disease. Seventeen patients with celiac disease established clinically and confirmed by jejunal biopsy were studied. H2-BT was performed before and after treatment with a gluten-free diet for at least five months. Alveolar breath samples were obtained before administering orally 25 g of D-xylose and thereafter at 30 min intervals for 5 hr. Samples were analyzed for H2 by chromatography. Simultaneously, the 5-hr urinary excretion of D-xylose was determined by colorimetry. Gluten removal significantly decreased the H2 delta change (from 56.5 +/- 5.9 ppm to 32.2 +/- 8.8, P < 0.05). A similar decrease was observed in the area under the curve (P < 0.05). Conversely, urinary D-xylose excretion increased significantly (P < 0.05). Eleven of the 17 celiacs clinically improved after treatment. The H2-BT normalized in every patient who entered remission on the gluten-free diet, whereas the urinary D-xylose excretion remained abnormal in six of them. In the six nonresponder patients the H2-BT remained high in five, whereas urinary D-xylose excretion paradoxically normalized in 2. We conclude that H2-BT with D-xylose is a useful and practical test for the follow-up of celiac disease and is simpler and more reliable than the urinary D-xylose test.