You are right ... there is no telling what we get in some of our "food", sad to say. I do not have Celiac Disease, but I am aware of how severe it can be and the accompanying pain and misery. My issue years ago was with a severe case of Candida albicans in the gut. When your gut is messed up in any way, you are messed up ... and severely miserable. Unfortunately, the great majority of doctors at that time weren't inclined to even believe that Candida was a real condition.
We need to have as much info in our nutritional "arsenal" as we can these days.
