There are very few studies on the combination of naturally occurring substances in foods and added substances and herein lies a major problem with additives, agrochemical residues etc.
Wheat is a common allergen already with our without anything introduced naturally or by man.
Wine beer and yeasts are already not tolerated - high in amines. Adding Bt toxins, antibiotic marker genes, enzymes to confer chemical resistance etc to food is absolute madness in my view. The food is not chemical resistant. Some varieties of the plants are. Cotton seed oil has no resistance to chemicals, antibiotics, or insects or DNA or protein.