New insights into wheat toxicity: Breeding did not seem to contribute to a prevalence of potential celiac disease's immunostimulatory epitopes

Abstract

Gluten proteins, namely gliadins, are the primary trigger of the abnormal immune response in celiac disease. It has been hypothesised that modern wheat breeding practices may have contributed to the increase in celiac disease prevalence during the latter half of the 20th century. Our results do not support this hypothesis as Triticum aestivum spp. vulgare landraces, which were not subjected to breeding practices, presented higher amounts of potential celiac disease's immunostimulatory epitopes when compared to modern varieties. Furthermore, high variation between wheat varieties concerning the toxic epitopes amount was observed. We carried out quantitative analysis of gliadin types by RP-HPLC to verify its correlation with the amount of toxic epitopes: ω-type gliadins content explain about 40% of the variation of toxic epitopes in tetraploid wheat varieties. This research provides new insights regarding wheat toxicity and into the controversial idea that human practices may have conducted to an increased exposure to toxic epitopes.

Keywords: Celiac disease; Gliadins; Gluten; RP-HPLC; Toxic epitopes.