Do you just want to trip out or are you researching their potential therapeutic effects? Apparently non-hallucinogenic doses can antagonise serotonin, which actually produces some health benefits. I can’t remember the details, but it’s interesting that research was banned around the time serotonin-boosting antidepressants started being handed out like candy, and getting people to believe that serotonin is the “happy hormone” could make you a lot of money. I read something about research possibly resuming recently. Not sure how that turned out though. Hallucinogenic doses would be at your own risk, I guess. I don’t know anything about it personally.
As for moulds and such, I think it’s pretty much a case-by-case deal. Kefir contains tens of yeasts, including a candida strain or too. The fungi in parmesan co-inhabit the cheese with various probiotic bacteria. One strain, S. boulardii, is incredibly antagonistic to candida. Certain mushrooms like shiitake stimulate the kind of immune response that helps fight off pathogens like candida. If you eat mouldy tubers, you’ll get the squits and picking the wrong mushroom will send you to the morgue. In short, unless you look it up, it’s a bit of a crapshoot.