Background
The avoidance of gluten (in the meaning wheat, rye and barley containing food) is definitely widespread and has reached considerable proportions. The number of people avoiding gluten in the absence of diagnosed or probable celiac disease probably outnumbers those whith celiac disease. Although good, population based data are lacking, the reasons in the population to go gluten-free encompass abdominal problems as well as ”life-style” considerations. The question to be discussed is whether ”non-celiac gluten sensitivity” is to be considered as a real clinical entity or could be due to confounding effects, e.g. reduction of FODMAP.
Objective
To discuss the scientific documentation of NCGS as a clinical entitity
Outcomes
The current documentation is hampered by lack of general agreement on the clinical criteria for the patient group. The published gluten challenge trials usually fail to separate effects caused by gluten itself, other gluten related proteins and FODMAPs that is abundant in gluten-containing cereals. Serial interventions with FODMAP reduction preceeding gluten reintroduction does not mimic the clincal situation, and positive challenge controls in relevant patients groups are lacking. Gluten as an inductor of FODMAP sensitivity has not been studied. It has been stated that FODMAP reduction is resource demanding, and that it is unlikely that so many patients could have managed without proper instructions. Thus, NCGS as a clinical entity has not been dis-proven. There are several reasons to accept its existence, including widespread use, serological signs with increased IgG to gluten in NCGS patients, intraepithelial lymphocytosis seen in tissue sections, and induction of intestinal immune mediators like IFN-gamma by oral wheat challenge.
Conclusion
The clinical entity NCGS is a ”new disorder”, with a history during 3-4 decades, and with increasing documentation for its existence.