I know that an actual serious question is ... not a good idea in this thread.
But(t), can an actual microbiologist opine on why the particular stable mix of microbial species needed to crowd out C. diff in the GI not be cultured in a more reproducible manner, i.e. without further resort to human donors?
It's a great question that a lot of folks are working towards. The major problem is that it's just so damned complicated. The gut has usually hundreds or thousands of species of bacteria, archaea, fungi, protists, etc, and the vast majority have never successfully been reproducibly cultured (probably because they can't grow in oxygen and need cofactors from other microbes or the body to thrive). There's also a slew of bacteriophages that target and kill specific bacteria but are practically invisible unless you know where and how to look for them. So with all that complexity, we really have little clue which bugs are important.
The goal for this and other microbiome/probiotic work is to eventually create these defined and characterized microbial communities to grow safely and at scale for all sorts of potential therapies (my own work is in neurodegenerative disorders). But until we understand how all these mostly unknown organisms interact together and with our own bodies, the easiest thing is to just take a microbiome from a healthy person and hope it does the job. It's a crappy system, but it's SO cool to see it actually working out.
