I was diagnosed with spondyloarthritis.
And at the same time hashimotos. My levels of thyroid antibodies was really high.
I was advised to rheumatologist to stop gluten, diary, anything from a cow and nightshade vegetables.
I couldn't manage the full autoimmune protocol diet immediately.
So I started with gluten free and nightshade vegetables.
After 2 months my thyroid antibodies were under 10 (had been in the thousands) which is considered normal. And my thyroid function is fine. I had various other things like tummy and digestive issues and rashes which disappeared completely.
Diary free and cow (beef) free made no difference to anything. I tried that during March.
On the vegetables: I've been able to reintroduce peppers. Tomato's are a big no no same for potatoes and artichokes.
I have been tested for ceiliac but the test was negative (prior to giving up gluten). However I read that you can be silent ceiliac and a biopsy would be needed for diagnosis. However I'd now have to gluten myself for that to work.
Try the gluten free it's quite easy to do.
I thought I'd miss lots of things being gluten free. But mostly I don't miss being ill all the time! I don't feel deprived either.
You've nothing to lose by trying it.