There is a substantial amount of science devoted to characterizing the gliadin protein in wheat. There are thousands of versions of this molecule, varying in amino acid sequence. But there are sequences shared by most forms of gliadin proteins. (These sequences can also be found in the gluten and glutenin proteins of wheat, as well.) Gliadin has been the recipient of many of the changes in modern high-yield, semi-dwarf wheat.
What is fascinating is that many of the adverse effects of gliadin consumption in humans have been drilled down to their structural basis:
Image Fasano 2013
Note the following on the gliadin “map”:
Red = direct cytotoxic segment (intestinal cell-destroying)
Light green = immune-stimulating segment (responsible for celiac disease)
Blue = bowel permeability segment (via zonulin activation)
Dark green = inflammatory interleukin release
Also scattered about (not shown in diagram) are the 4- and 5-amino acid sequences that, when released, bind to the opiate receptors of the brain, exerting their myriad effects that differ depending on individual susceptibility (appetite-stimulation, food obsessions, anxiety, mental “fog,” paranoia, auditory hallucinations, social disengagement, behavioral outbursts, reduced concentration, sleep disruption, depression, mania).
Intestinal cell destruction, immune stimulation, intestinal permeability, inflammation, opiates . . . and that’s just one protein in modern wheat!
The full text of Dr. Fasano’s summary can be viewed here.