If you want to debate the genes vs food on a small sample: I am a biologic only child, but I have an adopted sister. My mother had CD, my father has AS, both Auto Immune diseases. I have CD and have problems with my back and other joints (pre cursor to AS?). My sister has nothing. WE BOTH ate all the same foods growing up, grew up in the same environment, lived in the same house for our entire childhood, yet I showed signs of CD at 13. Sorry I don't believe that genes play NO part in this.
I am predisposed to Auto Immune diseases because of my parents history. Can food be a trigger, sure, cause, not in my opinion.
CD 20 years officially, 30 unofficially. 3 resections '93, '95 '97
Managing with strict low residue diet, keeping symptoms to a minimum. All test show small amount of ulceration, still have occasional blockages. But still have a great time with my 2 daughters and husband!
Prednisone, 6MP,Prevacid, B12 shots, Bentyl, Xifaxan.....