Your skin microbiome decides which mosquito species targets you

If you have ever watched a mosquito ignore your friend and beeline straight for your ankle, you have probably assumed you are simply a mosquito magnet, full stop. A new study out of Florida International University (FIU) says that is not quite right. Instead of one universal "type," each mosquito species appears to read a different chemical signature written by the bacteria living on your skin, which means the itchy answer to "why me" depends on which mosquito is asking.

Key takeaways

• Researchers tested 119 people against three mosquito species and found no one was highly attractive to all three, undercutting the idea of a single "mosquito magnet" trait.
• Each species keyed in on a different mix of skin bacteria and body-odor chemicals, meaning your risk from disease-carrying Aedes aegypti did not predict your risk from Culex quinquefasciatus.
• The findings are correlational, from a single research team in one U.S. city, and describe associations, not proof that any specific bacterium causes attraction.
• The team hopes the odor signatures they identified can guide new, more targeted mosquito repellents, though none exist yet.

Skin bacteria drive species-specific mosquito attraction

The core finding is that mosquito attraction is species-specific, and it tracks with the composition of a person's skin microbiome (the community of bacteria living on the skin) and the volatile organic compounds, or VOCs (odor molecules that evaporate easily and can be smelled), that those bacteria produce. Researchers led by neurobiologist Matthew DeGennaro at FIU tested 119 volunteers against three mosquito species and found that being a favorite target of one species said almost nothing about how appealing you would be to another. Attraction rates between Aedes aegypti and Aedes albopictus were only weakly correlated, and attraction to Culex quinquefasciatus barely correlated with either. No single participant ranked as highly attractive to all three species tested.

Why this matters for dengue, Zika and West Nile risk

The three species in the study are not interchangeable pests. Aedes aegypti and Aedes albopictus spread dengue, Zika and yellow fever, while Culex quinquefasciatus is a primary vector for West Nile virus in the United States. Because each species is drawn to a different set of people, someone who feels relatively safe from Aedes bites during the day could still be a prime target for a Culex mosquito hunting for a host after dark. The researchers frame their molecular signatures as a step toward "indicators of species-specific mosquito bite risk," meaning a person's individual disease exposure could eventually be estimated species by species rather than assumed to be uniform.

How 119 volunteers were tested against three species

To measure attraction without relying on people's memories or perceptions, the team used a device called a uniport olfactometer, a sealed tube that lets a caged batch of mosquitoes choose whether to fly toward a person's arm. Each of the 119 Miami-area participants was tested live against Aedes aegypti and Aedes albopictus. Because Culex quinquefasciatus hunts at night, participants instead wore nylon sleeves on their arms for 12 to 16 hours to trap their scent, which was then tested on the mosquitoes under dim, moonlight-level lighting. At the same visit, the team swabbed each participant's forearm and sequenced the bacteria present using full-length 16S sequencing (a genetic method that identifies bacterial species from a small skin or gut sample), and separately analyzed the VOCs given off by each person's skin using gas chromatography-mass spectrometry, a chemistry technique that separates and identifies individual odor compounds.

What this could mean for you, without overselling it

For a reader who suspects their gut, skin, or overall microbial makeup is behind a nagging health pattern, this study is a reminder that the microbes living on the body's surface are not passive passengers, they actively shape how the outside world, in this case mosquitoes, perceives and responds to you. High attraction to Aedes aegypti tracked with a skin microbiome rich in Staphylococcus bacteria, echoing earlier lab work on the same genus, while low attraction to that species tracked with higher levels of Pseudomonas bacteria, including Pseudomonas aeruginosa. None of this translates into a supplement, probiotic, or skincare product you can buy today to repel mosquitoes; the researchers themselves stop short of recommending any intervention. What is worth watching is the direction of the science: it suggests that future bite-risk assessments, and eventually repellents, could be built around a person's actual skin chemistry rather than one-size-fits-all formulas.

What the study cannot yet tell us

This is a single, correlational study, and the authors are explicit about its limits. The uniport olfactometer measures how attractive a person is in isolation, not whether a mosquito would choose that person over someone standing right next to them in the real world, which is a different and harder question. The nylon-sleeve method used for Culex quinquefasciatus approximates a live host but is not identical to one. The team's own statistical analysis noted their sample was underpowered to draw firm conclusions about race and ethnicity as factors, even though some of those comparisons reached statistical significance. And because bacteria were only measured as correlates of attraction, the study cannot yet say whether specific microbes cause a person to be more or less attractive, or are simply markers of some other underlying trait, such as skin pH or sweat composition.

Next steps: from correlation to mosquito repellent design

The DeGennaro lab, funded in part by the Defense Advanced Research Projects Agency (DARPA) and the Centers for Disease Control and Prevention (CDC), says the molecular signatures identified here, including compounds like sulcatone that other researchers have linked to the evolutionary shift of mosquitoes toward biting humans, are meant to seed "next-generation repellent design." That work, and any follow-up studies that test whether manipulating a person's skin bacteria actually changes real-world bite rates, has not been published yet. Related lab research has shown that engineering the skin microbiome of mice can measurably cut mosquito attraction, hinting at where this line of research could eventually head for humans.

Common Questions

Does this mean some people are immune to mosquito bites? No. Every participant in the study still attracted at least one of the three mosquito species to some degree; the study only found that no one was a top target for all three at once.

Can I test my own skin microbiome to see which mosquitoes prefer me? Not from this study. The researchers used specialized lab equipment and full-length genetic sequencing that are not available as a consumer product, and the findings have not been translated into any commercial test.

Is this the reason some people never seem to get bitten? It is one likely piece of the puzzle. Body odor chemistry, which is shaped by skin bacteria, appears to be a major driver of species-specific attraction, though the study notes that other factors, including body temperature, sex and possibly genetics, likely also play a role.

The study, "Individual humans are more attractive to certain mosquito species," was published in the journal iScience by researchers at Florida International University. It builds on earlier work on quorum sensing in Staphylococcus epidermidis and mosquito attraction and related research showing that engineering the skin microbiome of mice can reduce mosquito attraction. FIU's own research news release has additional background on the study team and its funding.

References

1. Kaylee M. Marrero, John S. Castillo, Dani Lucas-Barbosa, et al. (2026). Individual humans are more attractive to certain mosquito species. iScience. https://doi.org/10.1016/j.isci.2026.117006
2. Effect of Quorum Sensing by Staphylococcus epidermidis on Aedes aegypti Attraction (PLOS ONE). PLOS. https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0143950
3. Feng Liu, Iliano V Coutinho-Abreu, Robyn Raban, et al. (2024). Engineered skin microbiome reduces mosquito attraction to mice. PNAS Nexus. https://doi.org/10.1093/pnasnexus/pgae267
4. Every mosquito has a type, and you may not be it (FIU News). news.fiu.edu. https://news.fiu.edu/2026/every-mosquito-has-a-type-and-you-may-not-be-it