We've long known that the human body is home to all kinds of bacteria, fungi, and other microbes, and now scientists have completed the first ever map of all of these semi-disgusting critters. It was not an easy job, but now the census of the human microbiome is complete and the verdict is that we're disgusting—but don't worry, we're disgusting in a good way.
The bad news is that we have about 10 bacterial cells for every one of our own cells, and various microbes make about about one to three percent of our body mass. That could mean that some of us are carrying six or so pounds of bacteria around with us. But before you go on some crazy diet (aka overdose on antibiotics) to shed that microbial weight, you should know that most of the bugs we play host to actually do quite a lot to help us. They've all got specific jobs. For instance, gut bacteria helps us digest certain proteins and fats.
The map that scientists have created details what kinds of microbes we normally carry and where we carry them—skin, noses, intestines, vaginas, they're all covered in the stuff. A healthy person has somewhere around 10,000 species of microbes in and on them, but what's interesting is that while we all have bacteria, we don't all carry the same kinds. What they discovered is that different people have different kinds of bacteria in a given place on the body, but every variety performs the same function in that place. Cool.
Our bacterial makeup can also change over time, depending on our environment, diet, and other factors. For example, research has revealed that the kinds of bacteria that live in your vagina change when you're pregnant, probably to ensure that your baby has the safest passage possible into the outer world. This could explain why babies who are born via C-section and aren't exposed to vaginal bacteria are at higher risk for certain kinds of infections. Pretty crazy stuff.
So, now that doctors have this map of what's "normal," they want to start using it to study what changes when people have diseases, which could lead to possible treatments. Dr. Phillip Tarr, of Washington University at St. Louis, was one of the lead researchers on the project, and he explains, "This is a whole new way of looking at human biology and human disease, and it's awe-inspiring." Ok, yes, awe-inspiring, but also kind of freaky and more than a little gross.
Image via Juan Gaertner/Shutterstock.