This project aims to verify the hypothesis that spelt products are more tolerable than bread wheat products in a target group of individuals with self-diagnosed wheat sensitivity. In addition, the influence of different manufacturing processes will be considered.

Wheat cereals are known to be capable of triggering wheat allergy and celiac disease. The prevalence of both diseases is about 1%. Recently, another clinical entity was described, the non-celiac wheat sensitivity (NCWS). The origin and mechanisms of NCWS are unclear at present, but the existence of this new disease entity has been proven by double-blind placebo-controlled challenge tests. Three different grain components have been proposed as triggers of NCWS, gluten, α-amylase trypsin inhibitors or fermentable carbohydrates (FODMAPs).

It is reported that individuals with self-diagnosed NCWS quite often tolerate spelt products much better, even though spelt shows a higher gluten content than bread wheat products. Therefore, the question arises whether this putative spelt tolerance can be confirmed on an objective basis and whether the underlying molecular mechanisms can be elucidated. So far, human study addressing such questions are lacking.

This project aims to verify the hypothesis that spelt products are more tolerable than bread wheat products in a target group of individuals with self-diagnosed wheat sensitivity. In addition, the influence of different manufacturing processes on wheat sensitivity will be revealed.

For this purpose, the trial involves individuals with self-diagnosed wheat sensitivity and spelt tolerance. Six different kinds of bread will be tested, including 4 wheat and spelt breads, each of them produced following a traditional or a conventional way. Aim of this part is to objective bread wheat and spelt intolerance in a defined population. To find out whether FODMAPs or gluten affect the tolerance of bread, two additional breads will be tested, a gluten-free bread with added gluten and a gluten-free bread with added FODMAPs.

Inclusion Criteria:

• Age ≥18 ≤70 years
• Signed declaration of consent
• Willingness to adhere to the prescribed diet for the duration of the study
• Subjective bread wheat intolerance
• No known spelled intolerance
• No acute or chronic gastrointestinal diseases (e.g. celiac disease / wheat allergy)
• No participation in another clinical trial (current or within the past 30 days)
• Gluten-containing diet at least 6 weeks before the start of the study

Exclusion Criteria:

• Taking intestinal therapeutics, antibiotics, immunosuppressants or similar
• Pregnancy / lactation
• Relevant violations of the nutritional protocol
• Occurrence of relevant diseases (possibly individual decision)
• Revocation of consent
• Accommodation in a clinic or similar facility based on an official or judicial order