An exploratory comparative investigation of Food Allergy/Sensitivity Testing in IBS (The FAST Study): A comparison between various laboratory methods and an elimination diet

ObjectiveTo determine the ability of several non-IgE mediated food allergy (NIMFA) test methods to identify which foods would elicit symptoms in irritable bowel syndrome (IBS) sufferers.MethodsThis was a correlative, hypothesis generating study. Participants (n = 4) with IBS (Rome III >200) provided blood samples for various marketed NIMFA tests (cytotoxic assay, IgG food antigen, electrodermal screening), prior to initiating an Elimination/Challenge diet. Eight foods were challenged following a 4-week elimination diet. Challenge foods were selected from reported reactive foods on test results. Participants and team members were blinded to the test results until study completion. Dietary choices and symptoms were tracked daily and reviewed bi-weekly. The IBS symptom severity scale (IBS-SS) was administered at each visit (n = 5).ResultsThere was poor agreement, assessed by Fleiss' kappa, between the various test results and those foods, on challenge, elicited a reaction. The sensitivity of the NIMFA tests ranged from 20 to 75%, while the specificity, from 50 to 89%.ConclusionNone of the NIMFA tests evaluated in this study were found to be diagnostically predictive in the identification of specific foods that exacerbate the gastrointestinal symptoms in our small sample of IBS sufferers.