Our bodies are coated inside and out with microorganisms. By some estimates, you are ten times as much microbe as you are you. In fact, it’s the bacteria on our bodies that give our sweat its scent, essential for identification by dogs and for attracting mosquitoes. But not all bacterial films are created equal.
According to a new study by Niels Verhulst of Wageningen University and Research Centre and an international group of colleagues, people with a lower diversity of bacteria on their skin are more attractive to the Anopheles gambiae mosquito. As this little menace is responsible for much of the malarial transmission in Africa, this finding could have implications in preventing disease.
The researchers compared the foot odor, a known A. gambiae attractant, of 48 male volunteers. You may be relieved to read that these subjects did not have to stick their feet into a mosquito chamber. Instead, glass beads were rubbed against their feet to collect volatiles, and then mosquitoes were allowed to approach the beads of their choice. At the same time, the total number and the diversity of bacteria on the men’s feet were determined.
Men with more total bacteria but less diversity were more attractive to the mosquitoes. Specific genera of bacteria correlated well with attractiveness (some were liked and some disliked by the mosquitoes). The authors speculate that this information could be used to develop mosquito traps and repellants.
For more information, Ed Yong includes a microbiology slide show on his post about this study.