ames is not correct in saying a scientist can “believe any theory”. Scientific theories have to be consistent with empirical fact. The truth is, we *don’t* know the mechanism by which HaShem created bacteria.
I am a scientist and I accept 100% all empirical scientific facts. I’d be an absolute fool not to! And I also accept 100% that “there is a god who created this wondrous universe” and indeed that is one reason I dedicate my life to studying it. But there is a lot of ignorance about the nature of science that unfortunately pervades the frum community as well as the non-frum. Science can neither prove nor disprove the existence of HaShem or the truth of His Torah. And the Torah is not a book of science or history but a teaching of how to live. The scientific material in our mesorah is not to be used as science lessons but as instruction for us in how to live. Proof that we are not to rely on the science of Chazal is that relying on their medical knowledge was prohibited back in the time of the Gaonim!
The best explanation of this distinction was actually by a non-Jew, Galileo: Religion is about “how one goes to heaven. not how heaven goes.”