I only post this disagreement with your post as an autoimmune enjoyer who has 0 genes for celiac (although my dad developed full blown celiac at age 55 without any previous symptoms in his life). Having dealt with autoimmune issues for a while and doing a lot of reading and discussions with my various rheumatologists over the years, I find it amazing how little is truly known about the immune system, role of food, role of microbiome, and root causes of auto immune issues. Moreover, the lack of understanding on how auto-immune disease prevalence has gotten way worse in recent decades (at least in the U.S.), way moreso than can be explained by increased reporting/increased life expectancy.
Some Links: NPR discussion on zonulin: A Protein In The Gut May Explain Why Some Can't Stomach Gluten https://www.npr.org/sections/thesalt/2015/12/09/459061317/a-...
An overview written by the author mentioned in the NPR Article: Zonulin, regulation of tight junctions, and autoimmune diseases ncbi.nlm.nih.gov/pmc/articles/PMC3384703/