Reference Number: 62
Intolerance & Sensitivity: Coeliac
Coeliac disease is an intolerance triggered by the ingestion of wheat gluten proteins. It is of increasing concern to consumers and health professionals as its incidence appears to be increasing. The amino acid sequences in gluten proteins that are responsible for triggering responses in sensitive individuals have been identified showing that they vary in distribution among and between different groups of gluten proteins. Conventional breeding may therefore be used to select for gluten protein fractions with lower contents of coeliac epitopes. Molecular breeding approaches can also be used to specifically down-regulate coeliac-toxic proteins or mutate coeliac epitopes within individual proteins. A combination of these approaches may therefore be used to develop a “coeliac-safe” wheat. However, this remains a formidable challenge due to the complex multigenic control of gluten protein composition. Furthermore, any modified wheats must retain acceptable properties for making bread and other processed foods. Not surprisingly, such coeliac-safe wheats have not yet been developed despite over a decade of research.
SIGNIFICANCE OF THIS STUDY
Currently thirty-one, nine amino acid peptide sequences in the prolamins of wheat and related species have been defined as being coeliac toxic and these are often referred to as coeliac “epitopes”. The current review demonstrates that there is extensive variation in the occurrence of coeliac-toxic epitopes within and between genetic variants amongst wheat species (such as diploid and tetraploid species), and in the levels of expression of these proteins. Although in some wheat specie may lack the above defined coeliac epitopes, it cannot be ruled out that they contain sequences which will stimulate a response in some individuals. The review explores the possibility of developing coeliac-safe wheat using a combination of technologies (genetic modification) but this may still require large investment of time and financial support.