the bacteria made me do it

I'm lifting this directly from a post that i made in another forum. Otherwise, it'll sink, and i'll forget where it went, like the stories of the destruction of the CIA torture tapes that i know are out there, months or years old

Considering that humans carry more bacterial cells in their bodies than human ones and infection with certain bacteria has been shown to alter behavior in the possible attempt to preserve the host from predators, could it be possible that aspects of our personalities may have nothing to do with our genetics, but are the output of various groups of bacteria working in symbiosis?

It's an old theme in sci-fi i think, but with each passing year, it seems more credible.