[Intestinal permeability in children with food allergy]

We have investigated intestinal permeability in 36 children aged 5 months to 12 years with food allergy. L-rhamnose (monosaccharides) and lactulose (disaccharides) were used as probe molecules to measure intestinal permeability. Sugars in urine were determined by high-performance liquid chromatography. The results of the test were expressed as the ratio (lactulose/L-rhamnose) of the 5 hour urinary recoveries of the 2 probe molecules. Lactulose/L-rhamnose excretion ratios in children with food allergy, range 0.0257-0.2630 (mean 0.0623), were significantly higher than those of the controls, range 0.0129-0.1085 (mean 0.0439) (p less than 0.02). There was a relationship between permeability and age in each group. The increased permeability was striking in children under 2 years of age with food allergy. These findings may reflect intestinal mucosal damage caused by local hypersensitivity reactions to food antigens. This is a simple and harmless method to measure intestinal permeability. Lactulose/L-rhamnose ratio appears to be a useful index of mucosal change in children with food allergy.