Non-celiac gluten/wheat sensitivity (NCGS)-acurrently undefined disorder without validated diagnostic criteria and of unknown prevalence: Position statement of the task force on food allergy of the German Society of Allergology and Clinical Immunology (DGAKI).

Imke Reese,Christiane Schäfer,Kirsten Beyer,Stephan C Bischoff,Paul Enck,Oliver Bachmann,Vera Mahler,Axel Enninger,Sonja Lämmel,Sabine Dölle,Lars Lange,Sabine Schnadt,Isidor Huttegger,Barbara Otto,Margitta Worm,Thomas Werfel,Ute Lepp,Hubert Mönnikes,Katharina Blümchen,Birgit Ahrens,Regina Treudler,Torsten Zuberbier,Anja Waßmann-Otto ,Barbara Ballmer‐Weber ,J Ockenga ,Jörg Kleine‐Tebbe ,Zsolt Szépfalusi

doi:10.1007/s40629-018-0070-2

Abstract

Within the last decade, non-celiac gluten/wheat sensitivity (NCGS) has been increasingly discussed not only in the media but also among medical specialties. The existence and the possible triggers of NCGS are controversial. Three international expert meetings which proposed recommendations for NCGS were not independently organized and only partially transparent regarding potential conflicts of interest of the participants. The present position statement reflects the following aspects about NCGS from an allergist’s and nutritionist’s point of view: (A) Validated diagnostic criteria and/or reliable biomarkers are still required. Currently, this condition is frequently self-diagnosed, of unknown prevalence and non-validated etiology. (B) Gluten has not been reliably identified as an elicitor of NCGS because of high nocebo and placebo effects. Double-blind, placebo-controlled provocation tests are of limited value for the diagnosis of NCGS and should be performed in a modified manner (changed relation of placebo and active substance). (C) Several confounders hamper the assessment of subjective symptoms during gluten-reduced or gluten-free diets. Depending on the selection of food items, e.g., an increased vegetable intake with soluble fibers, diets may induce physiological digestive effects and can modify gastrointestinal transit times independent from the avoidance of gluten. (D) A gluten-free diet is mandatory in celiac disease based on scientific evidence. However, a medically unjustified avoidance of gluten may bear potential disadvantages and risks. (E) Due to a lack of diagnostic criteria, a thorough differential diagnostic work-up is recommended when NCGS is suspected. This includes a careful patient history together with a food-intake and symptom diary, if necessary an allergy diagnostic workup and a reliable exclusion of celiac disease. We recommend such a structured procedure since a medically proven diagnosis is required before considering the avoidance of gluten.

Highlights

Non-celiac gluten sensitivity (NCGS) or non-celiac wheat sensitivity is an increasingly discussed disorder
We recommend a ratio of placebo to active of at least 2:1 in controlled challenges. This approach has been successfully utilized in a current study, determining that the majority of patients with suspected NCGS cannot identify gluten as trigger of their symptoms [26]
A temporary gluten reduction, but not total gluten avoidance is recommended in the German irritable bowel syndrome (IBS) guideline [27]

Summary

Introduction

Non-celiac gluten sensitivity (NCGS) or non-celiac wheat sensitivity is an increasingly discussed disorder. Keywords Gluten-free · Self-diagnosis · Nocebo effects · Placebo effects · Irritable bowel syndrome C. Schäfer Outpatient Center of Allergy and Pulmonology (Schwerpunktpraxis Collonaden), Dietary Counseling and Medical Nutrition Therapy, Hamburg, Germany

Results

Conclusion