The human body is a cluster of individual human cells that form tissues, blood vessels and organs – but those cells are only a portion of what makes you who you are.
Living on and in-between human cells are microscopic single-celled organisms called microbes, which include creatures like bacteria and fungus that are only visible with microscopes. These microscopic creatures outnumber the human cells in your body and play a vital role in training your body’s immune system against pathogens, processing hard-to-breakdown nutrients like fiber, producing essential vitamins... and producing your body odor.
On the skin, sterile and odorless sweat (containing proteins and lipids) is released by glands and this becomes food for bacteria. Certain bacteria, namely Staphylococcus and Corynebacteria, produce a potpourri of odors by metabolizing these compounds.
Our natural odor can have a large impact on many things, including our own health. Skin microbes produce your body odor, which has been shown to attract mosquitoes. Mosquitoes can carry diseases such as malaria and dengue fever – which are deadly in most parts of the world. Some researchers are working to modify the abundance of skin microbes that attract disease-carrying mosquitoes. A tool for changing the makeup of your skin microbes might not be too far in the future. Many people use underarm products like deodorant and antiperspirant, which inhibit bacterial growth and adds an artificial fragrance, masking our “natural odor.”
Body odor isn’t only attractive to mosquitoes. Another important role for smelly skin bacteria is their role in mate attraction. In the Genomics and Microbiology Lab at the N.C. Museum of Natural Sciences, we recently investigated the connection between underarm microbes and odor through a citizen science project called “Armpits, Microbes and Odor.” We enlisted volunteers to provide samples of microbes from their skin and to assess microbial odors in an event called “Speed Smelling.”
Our goal was to study the whole picture of underarm microbes; including their nutrition, their microbial odor and the attractiveness of those microbial odors. Visit the Armpit Gallery of our collaborators YourWildLife at NC State University (http://armpits.yourwildlife.org), which is full of bacterial pictures and research results.
Imagine choosing your mate based solely on their smell. Think about that the next time you’re at the gym!
Sarah Council is a postdoctoral fellow at the N.C. Museum of Natural Sciences and N.C. Central University.