Milk‐ and wheat protein drinks for double blind placebo controlled food challenge in adults: a simple tool for diagnosis

Increasing number of adults report food allergies, where > 50% express gastrointestinal symptoms after ingestion of certain foods [1]. Diagnosing diffuse gastrointestinal problems or hypersensitivity to certain foods often requires oral food challenges, especially when patient history is vague and/or clinical tests are inconclusive. Double blind placebo controlled food challenge (DBPCFC) is considered the golden standard model [2], but requires that the food tested is blinded i.e. differences between active and placebo products can’t be detected by taste, smell or texture. To prove this, sensory testing is needed. The most frequently used model is the triangle test where the purpose is to identify one odd sample regardless of type of difference identified [3]. However, most DBPCFC recipes have been validated within pediatric populations [4] and may not be optimal for adults, since higher doses normally are needed to provoke symptoms. Few studies have tested larger volumes for oral challenges or are not based on ordinary staple foods. Food hypersensitivity diagnose and irritable bowel syndrome (IBS) have been suggested to overlap in adult patients [5]. Although it has not been confirmed that food intolerance (self-reported) is related to IBS symptom severity, a low content of fermentable carbohydrates, as FODMAP, is preferable to avoid possible gastrointestinal symptoms caused by these [5, 6]. Aim To develop simple, validated recipes for DBPCFC drinks, based on ordinary staple foods, to be used as support for diagnosis of milk- and wheat protein hypersensitivity in adults.