Each individual has a unique olfactory signature, shaped by skin microbiota, sweat and volatile compounds emitted by the skin. These invisible odors play a central role inattracting mosquitoes, which detect certain molecules produced by skin bacteria.
Understanding how the microbiota metabolizes body secretions and generates olfactory signals helps explain why some people are bitten much more than others. This article explores biological mechanisms, recent studies and prospects for manipulating these phenomena to our advantage in mosquito control.
See our special report: Mosquito control in the Balearic Islands
The role of skin microbiota in body odor
What is skin microbiota?
The cutaneous microbiota refers to all the micro-organisms that inhabit our skin: bacteria, yeasts, fungi or microscopic mites. Each square centimeter is home to between 10⁴ and 10⁶ bacteria, depending on the area of the body. Their composition depends on genetics, gender, diet and climate.
This microbiota is no mere passenger: it interacts with the hydrolipidic film and directly modulates body odor. Certain species, such as Staphylococcus epidermidis or Corynebacterium, degrade fatty acids and produce volatile compounds responsible for characteristic odors, sometimes irresistible to mosquitoes.
From sweat to perfume: how bacteria transform secretions
Human sweat alone is odorless. It’s the bacteria of the cutaneous microbiota that transform secretions into a symphony of odors: carboxylic acids, alcohols, aldehydes and sulfur compounds.
Research shows that people who emit more isovaleric acid or 3-methyl-1-butanol are much more attractive to Anopheles gambiae mosquitoes. These metabolites, derived from bacterial degradation, are true chemical signals.
The lower the bacterial diversity, the more uniform and recognizable the odor becomes to insects – an olfactory signature that mosquitoes learn to spot.
In this way, the cutaneous microbiota acts as a composer of body odors. This invisible score already guides mosquitoes in their choice even before they perceive CO₂ or body heat.
Volatile skin compounds (VOCs / mVOCs): olfactory signals that attract mosquitoes
The cutaneous microbiota produces a mosaic of volatile organic compounds (VOCs) that form the basis of our body odor. These invisible but powerful molecules are dispersed in the air and become olfactory clues for mosquitoes. Their sensitivity is extreme: some VOCs are detectable at minute concentrations.
Each individual exhales a unique “chemical cloud”, influenced by his or her bacterial flora and secretions. This cloud acts like an olfactory identity card, capable of attracting or repelling different species of mosquito.
Chemical classes of attractive compounds
Carboxylic acids (butyric acid, isovaleric acid), certain alcohols (1-octen-3-ol) and aldehydes derived from sweat are among the most powerful attractants.
Bacteria in the skin microbiota metabolize sweat, transforming lipids and proteins into these odorant molecules. Some, like Corynebacterium tuberculostearicum, produce more of them, thus increasing individual susceptibility to the bite.
Studies linking volatile compounds and mosquito attraction
Studies carried out in East Africa showed that volunteers whose skin emitted high levels ofpentanoic acid attracted up to 2.5 times more mosquitoes than a control group.
Conversely, molecules such as heptanal or nonanal, associated with greater microbial diversity, appear to slightly repel insects. These variations show that the composition of skin microbiota directly influences the quantity and nature of skin volatile compounds emitted.
Like an olfactory score that only mosquitoes can read, these chemical signals reveal our biological differences.
Inter-individual variability: why some people are more attractive to mosquitoes
No two people exhale exactly the same body odor. This olfactory variability is largely due to the skin microbiota, whose composition differs radically from one individual to another. Some skins harbor more Corynebacterium, others more Pseudomonas; these differences modify the profile of volatile compounds and therefore theattraction of mosquitoes.
Research conducted at Rockefeller University revealed that people producing a lot ofC6-C10 carboxylic acids attracted up to 100 times more Aedes aegypti mosquitoes than others. These molecules, derived from microbial metabolism, form a persistent and recognizable odor.
The role of bacterial diversity
A rich, balanced skin microbiota seems less attractive. Poor microbiota, dominated by few species, produce uniform odors, thus easier for mosquitoes to identify.
Diet, hygiene, stress, perspiration and even cosmetics also influence the skin microbiome and thus the intensity ofolfactory attraction.
In athletes, the combination of heat + CO₂ + metabolites from sweat creates an amplified olfactory signal, explaining why mosquitoes sometimes seem to “adore” heated skin.
This subtle orchestration between microbes, sweat and human behavior shapes our chemical signature – and could one day become modulable at will.
See also: Interactions between sunscreen and mosquitoes
Towards microbiota manipulation strategies to repel mosquitoes
Research is now exploring an innovative approach: manipulating skin microbiota to reducemosquito attraction.
Rather than masking odors, scientists are trying to act directly on the skin bacteria responsible for attractive volatile compounds. Preliminary tests have shown that adding certain probiotic strains to the skin can reduce carboxylic acid production by up to 40%.
Other teams are testing modified bacteria capable of naturally releasing repellent molecules such as geraniol or citronellal.
Limits, challenges and prospects
Modifying the human cutaneous microbiota remains a complex task: strain stability, compatibility between individuals, dermatological safety.
Some approaches involve applying cutaneous prebiotics that favor bacteria that produce less attractive VOCs, thus transforming the skin into a repellent biological barrier.
This research opens the way to a living protection strategy, based on dialogue between microbes and skin: no longer killing mosquitoes, but changing the chemical message they perceive.
Practical applications: what can we expect / do today?
Until science makes targeted modulation of skin microbiota possible, certain habits can already reduceolfactory attraction:
- Maintain balanced skin hygiene, without using too much antibacterial soap;
- Maintain a healthy microbiota with a varied, high-fiber diet;
- Avoid sweet fragrances and deodorants containing molecules close to attractive VOCs;
- Use natural repellents based on citronella, lemon eucalyptus or geraniol;
- Wear light-colored, loose-fitting clothing that limits the thermal and olfactory signals detected by mosquitoes.
Well-moisturized skin also emits fewer sulphur compounds, which are often highly attractive. These gestures do not profoundly alter the microbiota, but they do weaken the olfactory signature that attracts insects.
Tomorrow, they could become the basis of a biological anti-mosquito strategy, combined with technological solutions such as those developed by Mosquizen.
Transforming your olfactory signature: the new anti-mosquito frontier
Our body odors, shaped by our skin microbiota, determine our vulnerability to mosquitoes. Understanding this intimate interaction between bacteria and volatile compounds opens the way to intelligent biological protection.
While we wait for science to remodel our microbiota, Mosquizen’s Mosquizen solutions already offer concrete, ecological and sustainable protection: mosquito bollards, controlled attractant diffusers, insecticide-free devices that respect the environment.
By acting on the environment rather than on the body, they extend the idea of better understanding biology in order to better protect against it.
The battle against mosquitoes is now being waged at the frontier of the living world – between the chemistry of our skin and Mosquizen technology.
