You Are a Busy Place!
It has been made into a joke where royal persons referred to themselves in the plural, such as, "We are not amused". Although they had no way of knowing it, they were more correct than they knew — but for different reasons. We are not alone inside ourselves. There are billions of microorganisms living there, coexisting and even helping us thrive.
Naturally, evolutionists will assert that they gradually evolved along with us, but they do not offer models, believable explanations or anything other than assertions. In fact, to want us to believe such a thing is asking quite a bit. Further, they equivocate "evolution" with "adaptation", and make it sound like microbes-to-man evolution is realistic, but such a word game is disingenuous at best. It makes much more sense to believe that they are doing what they are designed to do from the beginning.
By learning more about “who” lives in you in sickness and in health and what they are doing, medical scientists hope to recruit microbial aid to help the body fight not just infections but also noninfectious diseases and conditions ranging from premature birth to cancer.
The human placenta, for instance, hosts an assortment of bacteria similar to those in the mouth. These may well contribute to the normal progress of pregnancy, provide useful metabolites to the fetus, influence the development of the fetal immune system, and either promote or prevent premature labor — depending on the composition of the bacterial population. Research in this area is ongoing, and Baylor College of Medicine maternal-fetal medicine specialist Dr. Kjersti Aagaard says, “These discoveries could lead to rapid breakthroughs in not only identifying women at risk for preterm birth, but developing new and worthwhile strategies to prevent preterm birth.”You can read the rest, in context, by clicking on "The Wonderful World of Bacteria in Your Body".