Gluten-free diet
A gluten-free diet ( GFD ) is a nutritional plan that strictly excludes gluten , which is a mixture of proteins found in wheat ( and all of its species and hybrids , such as spelt , kamut , and triticale ) , as well as barley , rye , and oats . 
<triplet> gluten <subj> protein <obj> subclass of <triplet> spelt <subj> wheat <obj> this taxon is source of