such a silly article it deserves an upvote. the beneficial bacteria are not actually you. Your body just tolerates them (they have evolved as symbionts) instead of treating them like ordinary alien invaders, because they provide a service to the body. They made a good move, by moving in with us. They have their own DNA and unlike us, bacteria can actually swap DNA with each other. That's why they can evolve so fast. It's one of the benefits of not having a cell wall !!