With all this new knowledge, what we learned is that each one of us can be thought of as a superorganism, a kind of human-microbe hybrid.2042 The human colon has been considered the most biodense ecosystem in the world, meaning there’s more life concentrated in our colons than anywhere else on Earth.2043 Many probably think that stool is composed primarily of undigested food, but most of it—about 75 percent—is pure bacteria.2044
