The first place to always look imo is the gut based on Occam's principle. If not then other places are of course non-gut infections and even autoimmune disorders. That is my two cents at least. For 90% of the people on these forums who have an immune system component, i.e. not nervous system dysfunction only, the problem is probably in the gut. One of the likeliest of that is of course a leaky gut since that really pisses off the immune system.
Before my ordeal started, back when I was still in SE asia, I did have a huge gut problem. It started from one day to the other, with severe pain, appetite loss and diarrhea. I was tested several times, no bugs were found, and they diagnosed IBS. I say, lose the "I" and just call it BS. No doubt there was some infection. It took 2-3 months to get over it. Around the time I was starting to feel better, I took those supps I described earlier. So it is possible that some immune (gut) problem precipitated this.
I do not now have any obvious gut symptoms. I have no pain, no constipation or diarrhea, and regular movements. The consistency does change from day to day, but I can usually ascribe this to changes in electrolytes or neurotransmitters. Still, I have taking several courses of bug killers over the years (not antibiotics) though, and maybe they have helped. As it is, zinc carnosine also helps with h pylori and leaky gut. In fact, I started it on suspicion of leaky gut. I also take NAG. I think I am going to do the Metametrix GI profile and see if anything turns up nonetheless.
Of course once things have progressed long enough that is when you can get into a bear trap where the norepinphrine has risen and the immune system keeps going and the two egg each other on since many of your other controls are shot. That SSRI has probably helped you more than you may realize.
Right, and that is the reason I got on the SSRI. They have been shown ns several studies to (at least partially) restore the HPA. I am only on half the recommended dose, though. I have found myself to be very sensitive towards SSRIs, and the few times I tried to increase beyond half the dose, I didn't succeed. I am trying again now. We will see how it goes this time. Fluoxetine has a half life of 1 week, so I usually feel fine in the beginning when I increase the dose, but later it builds up too much.