I've been using Genestra Brands' HMF Powder- it's supposed to be human strain acidoph. & bif., w/ fruchto-oligo....Apparently the original culture was taken from a woman's vagina in the 1940's. INteresting.....So far I think it's good stuff. I used to make my own keifer, not a in crock, just in jars and then would strain out the whey, rinse the curds w/distilled, and start over. It needs constant babysitting, though, and after a couple of months, I would lose it. I know it had lots of live cultures, but I still had bloating from the dairy.