Get Body Buddies The Microbes That Live In And On Us

These pathogenic bacteria, virus, and other microorganisms cause infections or make toxins that harm our bodies. Many of the symptoms that make a person suffer during an infection—fever, malaise, headache, rash—result from the activities of the immune system trying to get rid of the infection in the body.

The microbes that normally live in associations with humans on the various surfaces of the body (called the normal flora), such as Lactobacillus and Bifidobacterium, are known to protect their hosts from infections, and otherwise promote nutrition and health.

The most abundant microorganisms on human skin are bacteria, while the least common appear to be fungi. Bacteria on the skin can serve to prevent the invasion of pathogens and promote disease, depending on which colonies prevail.

This bacteria lives in our gut and helps us digest milk and fight off pathogens. We also have microbes on our skin, some of which digest sweat, making it smell. It is estimated that a massive 100 million bacterial cells live on and in our bodies, ten times more bacterial cells than human cells.

Microbes inhabit just about every part of the human body, living on the skin, in the gut, and up the nose. Sometimes they cause sickness, but most of the time, microorganisms live in harmony with their human hosts, providing vital functions essential for human survival.

Types of human microbiota include bacteria, archaea, fungi, protists and viruses. Though micro-animals can also live on the human body, they are typically excluded from this definition.

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.