Nowadays, the gluten-free diet is getting more and more popular. However, according to the present stand of the dietetics and nutritional sciences, only people diagnosed with coeliac disease have to be on a gluten-free diet. But people proven not to be suffering from coeliac disease report the remission or disappearance of their symptoms after excluding gluten from the diet.

The gluten-free products and gluten-free diet have already become a trend and more and more people link the “gluten-free” notion incorrectly to a healthy way of life in general.

Scientists use the non-coeliac gluten intolerance (NCGI, non-coeliac gluten sensitivity, NCGI, non-coeliac wheat sensitivity, NCWS) name for following case, when

the coeliac disease can be excluded based on the corresponding diagnostic guideline, and the wheat allergy can be excluded based on the specific allergy tests, but food containing gluten (like wheat, rye and barley) induce intestinal and/or extra intestinal symptoms and after the exclusion of these cereals remission is achieved or the symptoms disappear totally. The clinical picture in these cases often overlaps with the one of the irritable bowel syndrome.

As the definition of the non-coeliac gluten intolerance says, the coeliac disease is obviously proven not to be the cause of the symptoms. In case of non-coeliac gluten intolerance, the gluten may not trigger the symptoms. The wheat, rye and the barley contain more components, like fructans or soluble proteins, which could induce symptoms.

In similar cases a double-blind placebo-controlled food challenge (DBPCFC) should be implemented after the exclusion of wheat allergy and coeliac disease, which could help identify the concrete compounds behind the symptoms, but the DBPCFC in many cases is not implemented and the patients start to follow a gluten-free diet, make self-observations and state a self-reported gluten intolerance/gluten sensitivity.

In a randomized, cross-over, double-blind, placebo-controlled, human clinical study using gastrointestinal symptoms scale, the physiological effects of gluten and fructan were tested on 59 volunteer with self-reported non-coeliac gluten intolerance. To exclude coeliac disease, volunteers were genetically tested to HLA DQ2/DQ8 genotype and they were implemented a duodenal biopsy examination during gluten exposition and to exclude wheat allergy they were tested to specific IgE antibodies. Volunteers usually had symptoms similar to irritable bowel syndrome and in the past they experienced remission after beginning a gluten-free diet. Volunteers have consumed muesli bar containing gluten or fructan or placebo bar for 7-7-7 days with a one week wash-out period between the test weeks. There were no significant differences in case the symptoms between the gluten containing diet and placebo diet, but consumption of the fructan containing muesli bar induced some of the symptoms to a certain extent.

Fructan is a fructose containing polymer, which occurs in a large amount, in the sideways gluten containing wheat, rye and barley. It has a possibility, that the significantly reduced fructan content due to a gluten-free diet could ease the symptoms in non-coeliac gluten intolerance, instead of the exclusion of the gluten itself. According to the study, it is possible, that in some cases not the real compound, but the gluten is incorrectly blamed for the symptoms, which could be induced by the fructans, too.

When in the future there would be scientific evidences and a scientific verification for the presence of a so called “fuctan sensitivity”,

In case the presence of a so called “fuctan sensitivity” is scientifically proven, a market demand for lowered fructan containing and fructan-free products would appear.

Skodje GI, Sarna VK, Minelle IH, Rolfsen KL, Muir JG, Gibson PR, Veierød MB, Henriksen C, Lundin KEA. Fructan, Rather Than Gluten, Induces Symptoms in Patients With Selfreported Non-celiac Gluten Sensitivity, Gastroenterology (2017), doi: 10.1053/j.gastro.2017.10.040.

Henggeler JC, Veríssimo M, Ramos F. Non-coeliac gluten sensitivity: A review of the literature. (2017). Trends in Food Science & Technology 66. 84e92.