Comment by pesus

This is only anecdotal, but probiotic supplements absolutely had a large impact on my social anxiety. I can't remember for the life of me where I heard it, but I specifically looked for ones that with strains were "dirt-based" - PB-8 is the one I currently take. Looking back, I realized just how directly getting anxious was tied to having an upset stomach for me. The first week or so was a bit rough, but after that it's been smooth sailing. The supplements are so cheap that I think it's worth trying for a bit. Kombucha/other fermented foods may also have a positive impact.

Caveat: I have never been diagnosed with an anxiety disorder, so things may different in that case.