You may feel like you’re all alone sometimes, but you’re never really on your own. You’re covered in trillions of microscopic animals, called microbes. They’re living in your mouth, on your skin, and even in your important organs.
Believe it or not, that’s actually good news. You couldn’t survive without the millions of kinds of microbes in the world. For instance, some microbes help you digest food and make vitamins. The bad news is that not all microbes are helpful or harmless, and some can even kill. Microbes are also referred to as germs, especially the ones that can cause infectious diseases.
For a long time, people thought germ-borne illnesses could be conquered by science. In the late 1900s, new vaccinations and drugs seemed to have them on the run. But germs have bounced back. Drugs that once worked have lost their punch, while new diseases keep cropping up. Medicine has made huge strides in fighting germs, but Earth’s tiniest creatures remain our biggest foes.