August 16, 2012 | Looking at human beings as ecosystems that contain many collaborating and competing species could change the practice of medicine. 

A growing band of biologists sees people not just as individuals but as ecosystems. In their view, the descendant of the fertilised egg is merely one component of the system. The others are trillions of bacteria, each equally an individual, which are found in a person’s gut, his mouth, his scalp, his skin and all of his various crevices and orifices. The Economist