Earlier quoted context omitted.
Nah, I'd just not been able to think off hand of an example of intestinal flora being shared (potentially widely) among members of a species. The rabbits example is a good one to illustrate it already does happen. :)
Again, it is already known to be very common in humans.
Personally, I'm aware of https://en.wikipedia.org/wiki/Human_feces#Fecal_transplants, but that's all.