autoimmune disease, complete diet change

Hi. My story is actually not only about me but about me and my girlfriend. She was diagnosed with an autoimmune disease (Hashimoto) which they told her can only be treated with hormones. She did a lot of research and found out that she could change her diet to see improvements. But the catch was she is now cutting out anything with gluten, milk, industrial sugar, and lately even histamine. I never thought it could be done but she is sticking to the diet for over a year now and it has helped her a lot! So because we won't cook twice I also keep a similar diet and even if I am not that strict, it works wonders! I feel good and I can obtain a very good physical state without even working out a lot, i always had issues with my stomach but they are so much better. I can only recommend this kind of diet, even if someone doesnt have any allergies. Thank you !