That's an auto-immune disease, right? A lot of auto-immune diseases probably have leaky gut as their contributor. Getting off the wheat (off the gluten, gliadin AND agglutinin as well as other lectins from soy and legumes) is a huge help for that, one of the best things you can do. A lot of joint pain is also caused by chronic inflammation. Getting of the inflammatory processed oils and fats is also one of the best things you can do.