Similar approaches could also be applied to food intolerance as a consequence of substances present in some genera or species, such as gluten for people with celiac disease. Recently, PCR methods to identify the presence of rye, wheat and barley in products labeled as ‘gluten-free’, based on the analysis of plastidial markers (e.g. trnL),have been developed (Maskova, Paulickova, Rysova, & Gabrovska,2012).