Our gut microbes are different. They are natural parts of our lives. They help to construct our bodies — our gut, our immune system, our nervous system. They benefit us. But we shouldn’t let that lure us into a false sense of security. Symbiotic microbes are still their own entities, with their own interests to further and their own evolutionary battles to wage. They can be our partners, but they are not our friends. Even in the most harmonious of symbioses, there is always room for conflict, selfishness, and betrayal - https://www.brainpickings.org/2016/08/10/i-contain-multitudes-ed-yong/