I have GI issues (probably due to PsA), including SIBO, gastroparesis, and bile malabsortion/reflux. The Mediterranean diet seems to be the best at balancing my dietary needs, as I can't follow the FODMAP diet for SIBO or the low residue diet for gastroparesis, as they contradict each other.
For anyone with GI issues, I highly recommend drinking bone broth daily. It has many benefits. Otherwise, avoid red meat and sugar/processed foods.

Fish oil was helpful for my long-standing psoriasis. I also take vitamin D3. Both were recommended by my dermatologist. I've taken some steps toward an anti-inflammatory diet - olive oil, fish, avocados, etc., which also has been helpful.

I have both and I have recently worked with a nitritionist and have eliminated all added sugar. Only eating natural sugars in fruit or raw honey or pure maple syrup. I read every label and am eating more lean protein, whole grains and no bad oils. I feel much better and my labs have significantly improved. I buy my bread from a bakery that uses clean whole grains and no bad ingredients. The prigram was 12 weeks and it focused on one “Fix” per week. So it was relatively easy to manage. I know that many people do gluten free but I can’t give up good bread! Good luck in your journey!.

I was doing ok just before Covid, with vaccine and Covid infections my immune system has been hyper active. My PSA, psoriasis, flaring and blood sugar at extreme levels.

A few weeks ago I received results for another food intolerance testing. Compared to prior Covid I now recorded increased levels of intolerance and a spread of 10+ more foods added to the list.

I am now again back into full exclusion of so many foods.

Inflammation, fatigue, psoriasis, brain fog etc etc are reducing and for the first time since pre Covid I'm feeling so much better.

So, where diets are concerned, my advice from my recent experience is to get some quality testing to identify your specific intolerances and then frame your diet around those results.
(Food intolerance testing needs to be done again and again over time as my autoimmune condition is a constantly mutating menace)

Inflammation due to food intolerance appears to be key for me in managing my flares.

I went onto a completely gluten free diet.