https://en.m.wikipedia.org/wiki/Science_of_Identity_Foundation

She’s in a cult

Oh hey! Sorry for the slow reply, I just noticed the notification . I got mine at a homebrew store, but here they are on Amazon

Water kefir is another good option - one you get the grains rehydrated it makes a new batch every 24 hours or so, and you can referment it with fruit juice to make a fizzy probiotic drink. It’s much easier to get started with than kombucha