Randomized Double-Blind Placebo-Controlled Trial (Wheat vs Placebo) in Wheat Sensitive Patients for Evaluation of Bio-Markers of a Single Referred Symptom (Bloating & Swelling)

Gluten is the most important protein component of some grains, notably wheat, rye, and barley, which are the basis for a variety of wheat-derived alimentary products consumed throughout the world (bread, pasta, pizza etc). However the "engineering" of gluten-containing grains created the conditions for human diseases related to gluten exposure. These forms of gluten intolerance represent a heterogeneous set of conditions, including celiac disease, wheat allergy and gluten sensitivity, that, combined, seems to affect about 10% of the general population. The frequency of not-celiac gluten sensitivity is however still unknown, even though it is possible that this condition have been undiagnosed and under-diagnosed by the physicians for a long time. The immune responsiveness to wheat antigens represents a complex process, and its establishment and maintenance are not completely elucidated. The most frequent diseases caused by wheat ingestion are T cell-mediated disorders, i.e. celiac disease and immunoglobulin E (IgE)-mediated allergic reactions. However, besides celiac disease and wheat allergy, there are cases of gluten reactions in which neither autoimmune nor IgE-mediated allergic mechanisms are involved. These are generally defined as gluten sensitivity. Some subjects, who experience symptoms when eating gluten-containing products and show improvement when following a gluten-free diet, may have gluten sensitivity instead of celiac disease or wheat allergy. Gluten sensitivity patients are unable to tolerate gluten and develop an adverse reaction when eating gluten, that, usually, and differently from celiac disease, does not lead to small intestinal damage. Gastrointestinal symptoms in gluten sensitivity patients may resemble those associated with celiac disease, but the overall clinical picture is generally less severe and is not accompanied by the occurrence of autoantibodies (i.e. anti-tissue transglutaminase, tTG, or anti-endomysium, EMA) or autoimmune disease (i.e. Hashimoto's thyroiditis). Typically, the diagnosis is made by exclusion, and an elimination diet and an "open challenge" (i.e., the monitored reintroduction of gluten-containing foods) are most often used to evaluate whether health improves or worsen with the elimination or reintroduction of gluten in the diet, respectively.

As it is not known what cereals components determine the symptoms in the so called gluten sensitivity patients, we prefer to define this condition as "wheat sensitivity" instead of "gluten sensitivity".

Wheat sensitivity can cause both gastrointestinal and extra-intestinal symptoms; among the latter, the patients often reported body's swelling (hands', fingers', arms' , face's swelling).

This study has two major aims:

1. Evaluation of the effective dependence from the wheat ingestion of the clinical alterations presented by patients with diagnosed gluten sensitivity, with particular attention to abdominal bloating and body's swelling. The study will be done after a period of gluten-free diet (at least 30 days), using a double-blind placebo-controlled challenge with wheat or placebo (xylose), performed by administering capsules coded as A or B containing wheat or xylose, respectively. Capsules A or B will be administered once, and then, after 1 week of washout, the patients received the other capsules, given once too.
2. Before and 2 hours after every challenge, patients will undergo a complete medical examination, and The investigators will perform bioelectrical impedance analysis and collect blood sampling, for identification of possible markers that may be of help to demonstrate and explain the mechanisms of the examined symptom.