A friend of mine convinced me to try growing my own Lactobacillus GG in what is essentially sugar water.
I then wondered, "is there a more complete probiotic regimen I could use?" And, "how do I know the same probiotics I started with are what is still living in my culture?"
The answer to the first question is VSL#3.
According to some impressive-looking sources I found, this stuff is proven to work for serious digestive troubles.
The answer to the second question I'm still working on. For now I'll go on the principle that it's better to start with all the strains and hope they survive than to not start with all the strains.
The plan? Get some VSL#3 and make Coconut Yogurt with it. If it works, the cost of the VSL#3 could be mitigated by keeping an active culture going.