Non-celiac gluten/wheat sensitivity (NCGS)—a currently undefined disorder without validated diagnostic criteria and of unknown prevalence

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.

Self-Reported Non-Celiac Gluten Sensitivity in Brazil: Translation, Cultural Adaptation, and Validation of Italian Questionnaire

“…Over the years, the number of studies on this topic and the number of patients diagnosed with NCGS has significantly increased. It is difficult to access the exact prevalence of NCGS since we still do not have validated biomarkers for the diagnosis of NCGS [2,7,8,9]. However, previous studies have reported a prevalence rate of NCGS between 0.5 and 13% [1,6,10,11].…”

Gluten Detection Methods and Their Critical Role in Assuring Safe Diets for Celiac Patients

“…The prevalence of NCWS has been documented to range between 0.6 to 13% in the general population. However, because of the lack of diagnostic criteria, biomarkers, and misconceptions on self-diagnosis, the actual prevalence of NCWS cannot be established with a level of confidence today [70]. These epidemiological studies have suggested that gluten-associated disorders are common around the globe, and reflected toward a need for the "gluten-free" products.…”

Mikrobiota und Reizdarmsyndrom – eine kritische Bestandsaufnahme

“…Es ist daher nachvollziehbar, das der langfristige Einsatz von Low-FODMAP-Diäten mit hohem Proteinanteil zumindest problematisch ist [68], solange Langzeitstudien fehlen [69]. Im klinischen Alltag wird empfohlen, sukzessive FODMAPs wieder zuzuführen und die Symptomentwicklung zu beobachten, vergleichbar der Strategie bei einer anderen fragwürdigen Therapie, der glutenfreien Ernährung in der Nicht-Zöliakie-Population [70]. In den vergangenen 15 Jahren (bis 2015) wurden mehr als zehn Metaanalysen und systematische Übersichtsarbeiten zur Wirksamkeit von Probiotika veröffentlicht [72 -79], aber keine war in der Lage, zu einem eindeutigen Fazit zu kommen; ebenso weitere Metaanalysen von 2018 und 2019 [71].…”