Microscopic creatures—including bacteria, fungi and viruses—can make you ill. But what you may not realize is that trillions of microbes are living in and on your body right now. Most don't harm you at all. In fact, they help you digest food, protect against infection and even maintain your reproductive health.

What are the importance of microbes?

For example, each human body hosts 10 microorganisms for every human cell, and these microbes contribute to digestion, produce vitamin K, promote development of the immune system, and detoxify harmful chemicals. And, of course, microbes are essential to making many foods we enjoy, such as bread, cheese, and wine.

Why are microbes important to humans?

Microbes play an important role in our body shape by helping us digest and ferment foods, as well as by producing chemicals that shape our metabolic rates. Eisen explains, “It seems that disturbances in our microbial community may be one of the factors leading to an increase in obesity.”