Joe
If you have SIBO bacterial or yeast (no matter if candida or else)amaranth would not be so much help. In fact any starch (and amaranth has a lot) will cause brain fog and bloating.
I've had less problem with so called "puffy quinoa" is quinoa made as popcorn. Boiled quinoa I cant digest it. Did you tried bit boiled brown rice?
For me its also a matter or combining foods. Maybe you should combined them differently. I eat puffy quinoa with veggies casserole and bit butter 80% without any problem. that come after experimentation.
the best way to identify whioch food is wrong is to eat them separately. that way i was able to find out that rice flour, amaranth, millet etc was problematic for me. same with berries and youghurt.
fruits have lot of potassium and maybe for AF is not ok.
I found relief in adding digestive enzymes to help break down foods especially carbs.