In our skin billion live bacteria, organized in various communities and families. And it is this organization that determines how humans are attractive to mosquitoes.
According to new research in the Netherlands, who have a greater abundance of microbes on the skin, but with less diversity, are the favorite food of these insects.
And the discovery, the scientists report in the journal PLoS One , could have implications for the prevention of mosquito-borne diseases like malaria and dengue.
For bite victims mosquitoes are guided by several physical and chemical signals, including heat, humidity and fumes of human skin as sweat.
Without bacteria the sweat is odorless. These microorganisms are responsible for producing volatile compounds that give off the characteristic smell of every human being.
So the kinds of communities of microbes that live on the skin determines how a person smells.
Dr. Niels Verhulst and his team at Wageningen University conducted experiments with a female mosquito Anopheles gambiae, which plays an important role in the transmission of malaria in Africa.
The researchers wanted to determine if the composition of the microorganisms on the skin, called microbiota, has an impact on the attractiveness that a mosquito has to a human being.
In tests involving 48 healthy male adults between 20 and 64 years, 46 were Caucasian, one Asian and one Hispanic.
To determine the natural smell of the participants were asked not to drink alcohol or eat garlic, onions or spicy in the 24 hours prior to analysis.
In the experiment, samples were emanations from the skin of the feet of each individual twice during three different days.
The feet, the scientists said, produce volatile compounds that are known to be attractive to A. gambiae and this is one of the favorite places for this insect bites.
Then put the samples in containers with mosquitoes in captivity.
Mosquitoes were immediately attracted to the samples of nine of the volunteers, while the other seven were almost invisible.
By analyzing these two groups they found that the most attractive communities had more bacteria on your feet that the seven were rejected.
But these attractive communities of bacteria had a lower diversity. That is, bacteria but were more similar.
"The discovery of the relationship between skin microbial populations and attracting mosquitoes may lead to development of new ways to attract mosquitoes," says the researcher.
"And custom methods to protect against malaria vectors and other infectious diseases," he adds.