This still doesn’t make sense though because the thing in the shoes would be this ADA chemical, not gluten, unless they are like, recovering ADA that was used to whiten flour and /then/ putting it in shoes? If so this wasn’t really clear from the page you linked, which seems to mainly be ranting against ADA, including blaming the recent rise in celiac diagnosis rates and other gluten problems on the substance.
There’s also a part where the author claims 97% of Americans have undiagnosed celiac symptoms which is wholly ludicrous. Like, even if you deliberately poorly designed a study so that everyone who had a stomach virus in the past 5 years gets counted as celiac, this is just such a silly claim. The genetic marker needed to develop the disease isn’t nearly that prevalent.