EXCLUSION OF ATYPICAL FOOD ALLERGENS DETECTED BY CONFOCAL ENDOMICROSCOPY IS SUPERIOR TO A LOW FODMAP DIET IN PATIENTS WITH FOOD-SENSITIVE IBS

Background: Using endoscopic food challenge in the duodenum and confocal laser endomicroscopy (CLE), we recently demonstrated that up to 50% of patients with IBS show immediate mucosal reactions (mainly epithelial breaks and luminal plasma exudation) to one of four major foods (wheat>yeast>soy,milk).Molecular analysis showed an IgE-negative, partly eosinophilic, immediate (allergic) reaction with dysregulated tight junctional proteins.Aim: To compare the efficacy of a low FODMAP diet (LFD) vs the allergen exclusion diet (AED), as identified by CLE or gluten soup, vs a placebo diet (PD), in atypical food allergic patients with IBS.Methods: Rome III IBS patients with CLE-diagnosis of an atypical allergy to wheat, yeast, milk, or soy, and healthy controls (HC) were enrolled in the study, to receive either the PD, the LFD and the AED, each for 2 weeks with 2 week diet-free intervals in-between.At baseline and after each diet, symptoms were assessed using Francis symptom score, PHQ12SS, HAD questionnaires.Patients on LFD or AED were reassessed after 3 months.Data were compared using parametric and non-parametric statistics.Results: 52 patients (35f,46±15.4y) completed the study.42 were CLE+ (n=28 reacted to wheat, CLEw), n=8 to milk/soy/yeast (CLEo), 6 to a gluten drink (NCGS); n=10 were CLE-(9f,42±19y), n=14 HC (8f, 48.6±17y).All but one CLE+ improved >70% following AED.The Francis score decreased significantly after LFD in CLEw from mean baseline 308±68 to 220±94(p<0.001), being even lower after AED (189±101,p<0.001)and after 3 months (153±85,p<0.001).In NCGS it fell from baseline 303±62 after 2 weeks LFD to 208±106 (p=0.125), with further improvement after 3 months (134±35; ns), likely due to small number.No symptom change in PD 291,6±84,1(p=0,112).The PHQ12SS-score fell ns in CLEw on LFD, but significantly after AED (baseline mean: 7,9±4,4 auf 5,6±4,2(p=0,002), and further after 3 months (mean: 4.0±2.7,p=0.069).PHQ12SS in NCGS fell ns on LFD (baseline mean:7±4 vs 4±2,5;p=0.063);3 months AED scored better (mean:1.5±0.7)than LFD but remained ns, with no change on PD.Overall, the HAD anxiety improved significantly after LFD and further on AED (p<0.03,p<0.02, resp.).Conclusions: Symptoms, somatization and anxiety scored better with the CLE-guided allergen exclusion diet than with the LFD.In NCGS, specific gluten exclusion was not significantly better than LFD.These results support a prime role of specific atypical allergens in food-sensitive IBS patients.