re: Are gluten allergies more common now than they used to be?

Another factor is the amount of gluten-containing products in a highly processed diet. A potato is nearly gluten-free, but boxed Betty Crocker au gratin potatoes from a box contain wheat (and thus gluten). Ditto for Green Giant frozen broccoli in cheese sauce, and for almost all of the Hamburger/Chicken Helper type meal kits.

If you are gluten sensitive and eating non-processed foods, you may be able to tolerate the occasional slice of decent, nonprocessed bread. But a steady diet of sh*t in boxes can push your guts into unhappiness.

As yet unmentioned on this thread is the possible role of sh*tty supermarket bread. It goes from flour to plastic wrap in about two hours: thus it contains more gluten than a longer fermented, slower-rising loaf. Some gluten sensitive people tolerate very long fermented sourdoughs, but will flare on a higher-gluten-containing wheat item. It's worth noting that crap mass market wheat bread often has added wheat gluten to give it the spongy-squishy texture preferred by so many in the USA.