Ateist if evolution of morphing man or changing man into another substances or being?

that is called evolution, why do you have animals in your mouth, in organs lives a microorganism. isnt that single form of bacteria that evolves became one single stand. why do you have animals inside. for example in your mouth, they are tiny creatures that cleaning out that mouth licking it so that it neutralise odour and bad bacteria build up. so if you are tiny creatures bacteria that has been evolves through time why arent you single. but has many factual real animals living inside you, isnt evolution is hoax because you are not single bacteria that evolves..