It's not the gluten. Yes, Celiac disease is real and has been documented since Ancient Greece. That aside, my theory--and I think it's a good one--is whatever chemicals are being sprayed on the wheat are still there when the grains are made into flour. That's part of it. The other part of it is the crap that gets added back into the flour to reintroduce the nutrition content. The flour or bread you see on the shelves at the grocery store lose their nutritional value exponentially before they even make it to the shelves. Even the whole wheat flour. Sourdough or milling your own flour, or buying wheat berries or flour directly from the farmer would ensure that the quality and nutrition content is still there. Sourdough in a way regenerates some nutritional value due to the activity created in the sour starter by the native yeasts.