Evaluation of Intestinal Permeability in Food Allergy

Defective intestinal permeability may cause a break in tolerance and the development of food allergy (FA). We hypothesized that levels of intestinal permeability markers (IPM) would be higher in children with FA compared to atopic controls (ACs). FA (peanut, egg, milk, sesame, soy, tree nuts) was defined by oral food challenge or reported FA with positive food-specific skin prick testing (fs-SPT) in randomly selected LEAP participants. ACs had eczema, negative fs-SPT, and no FA. Relationships between clinical characteristics and IPMs (serum zonulin, sCD14 and Intestinal Fatty Acid Binding Protein (I-FABP)) measured by ELISA on the log10 scale were analyzed at baseline (4-11 months) and approximately 60 months (V60) using parametric tests and linear regression models. We evaluated 143 FA and 71 ACs. Levels of IPMs did not differ between FA and AC at baseline or V60 except for a trend of increased sCD14 in FA at V60 (p=0.066). I-FABP and zonulin levels significantly decreased between baseline and V60 in both groups whereas sCD14 increased in FA only (mean difference (MD):0.026 (95%CI: [0.001, 0.051]); p=0.044). I-FABP was elevated in peanut consumers compared to avoiders at V60 regardless of peanut allergic status (MD:0.089 (95%CI: [0.003, 0.174]); p=0.043). IPM levels were not associated with number of FAs, total IgE, eosinophils, delivery method, gestational age, or SCORAD. Serum IPM levels do not support greater intestinal permeability in FA compared to ACs. Higher sCD14 in FA may reflect hyper-inflammatory monocytes previously reported. Greater fat intake previously reported in peanut consumers may explain higher I-FABP levels.