Even when you close your bedroom door or take a shower, there’s an audience. You’re covered in trillions of microscopic animals, called microbes. They’re in your mouth, on your skin, and even in your important organs.
Believe it or not, that’s good news. Without the millions of kinds of microbes in the world, you couldn’t survive. 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 called germs, especially the ones that cause infectious diseases.
For a long time, people thought science could beat illnesses carried by germs. In the late 1900s, new vaccinations and drugs seemed to have them on the run. But germs have bounced back. Drugs that used to work have lost their punch. New diseases keep showing up. Medicine has helped a lot in fighting germs, but Earth’s tiniest creatures remain our biggest threat.
