I was running a little thought experiment in my head recently about the way we and most other living beings reproduce. As far as I'm concerned all sexual and most asexual reproduction happens in non-sterile environments. With mammals in particular the new generation develops inside the body of one of their parents, which in itself is full of microorganisms.

Now if we take a look at in vitro cloning studies most obviously work within substrates that closely resemble the natural environment of the species. But do said studies take into account the huge number of microorganisms involved? Maybe there are certain undiscovered or even known species of bacteria that most living beings have an undiscovered symbiotic relationship with, particularly one that plays a role in regards to the development and strength of their progeny. It doesn't seem too farfetched in my eyes, especially for mammals who already inherit part of the intestinal microorganisms from their mothers.
What do you guys think? Do you know of any interesting publications dealing with this topic?

>pic unrelated, Dolly was an in vivo clone with a surrogate mom