Little Creatures Among Us

THE MANY MICROBES IN OUR DAILY LIVES

- Marcus Woo

When you think you’re alone, you’re actually not. In the ground, the air, your room, and even your body are trillions and trillions of creatures so tiny you can’t see them. They’re microbes, and they’re everywhere. You’ve probably heard people call them germs— microscopic critters that you have to wash away with soap and water so they won’t make you sick.

Yes, some microbes can cause deadly diseases and infections. But, in general, they have gotten a bad reputation. Most aren’t harmful, and some are even good for you. Microbes in the soil can help plants grow. Those on your skin and in your body can help you stay healthy. Scientists have found that if people don’t have the right kinds of microbes in their guts—the stomach and digestive systems—there’s a greater chance they may have health problems, such as obesity, diabetes, and even certain types of cancer.

A Whole Other Scale

Look at the back of your hand. Millions of microbes are living on just one square inch of skin. Both inside and out, your body has tens of trillions of microbes (a number with 13 zeroes after it). You have about as many microbes as you have human cells in your body. That means half of the cells you’re walking around with are microbial. It’s like you’re only half human.

“If you were asked what are the species that live in your backyard or in your home, you might say there’s a cat, three humans, and a couple potted plants,” says Anne Madden, a biologist at North Carolina State University. “But most of life . . . exists at a whole other microscopic scale.”