Gluten sensitivity without coeliac disease – a new twist
Gluten-containing products are often blamed for contributing to various gastrointestinal and extraintestinal symptoms. While coeliac disease is a well-established entity, our understanding of non-coeliac gluten sensitivity (NCGS) is limited. Issues confounding progress in NCGS include the limited recognition of dietary components that often co-exist with gluten that might be triggering symptoms, lack of understanding of the mechanisms by which gluten might induce problems, and problems with clinical trial design and subsequent interpretation of results. A recent controlled trial using gold-standard elimination-rechallenge methodology in patients with self-reported NCGS has failed to confirm a gluten-specific effect on gastrointestinal symptoms. Furthermore, mechanisms by which gluten triggers symptoms remain unidentified. It is suggested that patients with suspected NCGS should explore other dietary triggers before exploring the gluten-free diet as an option.
Adoption of the gluten-free diet (GFD) is growing exponentially. This movement is supported by the belief that gluten is contributing to a wide range of health care concerns. Indeed, the demand for specialised gluten-free products and has fuelled a global market of gluten-free products approaching $2.5 billion (US) in global sales annually (1). A variety of allergic (wheat allergy), autoimmune (coeliac disease, dermatitis herpetiformis and gluten ataxia) and non-immune-mediated (non-coeliac gluten sensitivity) conditions encompass the spectrum of gluten disorders believed to be related to gluten exposure, the protein found in all forms of wheat, rye and barley (1).
The best studied and well understood gluten-related disorder is coeliac disease, which is an immune-mediated enteropathy precipitated by exposure to dietary gluten in genetically susceptible individuals (1, 2). The diagnosis of coeliac disease requires both a duodenal biopsy that shows the characteristic findings of intraepithelial lymphocytosis, crypt hyperplasia and villous atrophy and a positive response to a GFD (3). The only av ...