This has been a quest of mine, for the last year or so, that has yielded very little success. However, I just heard back from now foods and their probiotic products that are labelled vegan actually are vegan. They are derived from human intestinal flora and grown on a vegan medium.
Another product that looks promising, but not confirmed to be 100% vegan, is Dr. Ohhira's OM-X 100 Probiotic. This is made from vegetables that are fermented with lactic acid derived from tempeh and it looks to be of pretty good quality with 12 strains of bacteria. I don't know about the quantities though.
"When you are born, you are set forth to die. The fact that you live or don't live between these two dates depends solely upon your own will, opportunities and desires. The weight exerciser, of course, indicates that he chooses to live." Joseph Curtis Hise