Many of the most important and fascinating biological processes occur in a world so tiny we can't even see it without the help of a microscope. This is the world of microbiology. Although some people are grossed out by bacteria or fungi, these minuscule organisms play a huge role in our lives. Without them, life as we know it simply wouldn't exist!
Bacteria Are Everywhere
Because we can't see them with the naked eye, we often forget that bacteria are all around us. They can be found on our tables, in our shoes, on our skin, on our toilet seats and in our mouths! In fact, human beings, like any animal, are covered in bacteria. They can survive in almost any condition, too, from burning heat to freezing cold, from extremely low pH levels to extremely high ones.
They're Not Alone
Not only are bacteria found on just about any surface, they're often found with a few million of their closest friends. In fact, the human body contains more bacterial cells than human cells! Scientists have estimated that there are more bacteria in your mouth alone than there are people on the planet. That's a LOT of bacteria. Even after you spray your house with a disinfectant, many millions of bacteria still lurk in the nooks and crannies.
Not All Bacteria Are Bad
Although it can be kind of gross to think about all the bacteria on your skin or in your mouth, we couldn't survive without these diverse little microbes. It's true that some bacteria can make you sick, but the majority of the bacteria in your body actually work to keep you healthy. They fight bad bacteria, help you break down food and regulate your digestive tract. We need some bacteria in our systems just to be healthy!
Some Are Pretty Nasty
Unfortunately, not all bacteria are looking out for our best interests. Some species can cause some pretty gross diseases. Bacteria are responsible for ailments like food poisoning, meningitis, the bubonic plague and strep throat. Other microorganisms can be pretty harmful, too. One species of fungus causes athlete's foot, and another causes ringworm. Diseases like the chickenpox or the flu are caused by very tiny but powerful pathogens called viruses. But don't worry! There are bacteria in your body designed especially to fight off these unpleasant pests.