QUOTE : Your body is host to a microbiome: the trillions of other organisms that naturally inhabit your gut, respiratory tract, skin, and other organs. According to some estimates, there are ten times as many foreign microbes in your body as there are of your own cells, and altogether these microbes weigh several pounds.27 We coevolved with these microbes as well as with many species of worms over millions of years, which explains why most of your microbiome is either harmless or performs important functions, such as helping you digest and cleaning your skin and scalp.28 You depend on these critters as much as they depend on you, and were you to eradicate them, you would suffer. Fortunately, antibiotics and antiparasitic drugs don’t kill off your entire microbiome, but the overuse of these powerful medications does eliminate some helpful microbes and worms, whose absence may actually contribute to new diseases.