Reduced intestinal permeability in gluten-sensitive (GS) patients. Small intestinal permeability was probed by measuring the urinary cumulative 5-hour amount of lactulose (LA) (percentage of ingested), mannitol (MA) and the LA-to-MA ratio as described in (see Methods). Boxes represent the medians and interquartile ranges, and whiskers represent the range of independent determinations in 13 GS patients, 11 celiac disease (CD) patients, and 14 dyspeptic controls (DC) (see intestinal permeability section of the text, pages 8-9). *P < 0.05 relative to DC and †
P < 0.05 relative to CD (Mann-Whitney U test).