Poor Nutrition Makes People Smell More Attractive to Mosquitoes, Study Finds

Undernutrition, one of the most widespread health burdens on the planet, may be quietly reshaping the dynamics of some of humanity’s deadliest infectious diseases. A new study published in Cell Research by a team led by Gong Cheng of Tsinghua University, together with Jingwen Wang of Fudan University and colleagues, reports that insufficient nutrition renders hosts measurably more attractive to mosquito vectors and simultaneously more susceptible to the pathogens those mosquitoes carry. The findings, demonstrated in mouse models and corroborated in human subjects, suggest that malnutrition is not merely a passive background condition in regions where dengue, malaria, and other mosquito-borne diseases flourish, but an active biological driver of transmission. The work traces a complete mechanistic pathway that begins with a dietary deficit and ends with mosquitoes preferentially seeking out, biting, and acquiring or delivering virus from undernourished individuals, closing a feedback loop that could help explain why arboviral outbreaks so often concentrate in nutritionally vulnerable populations.

The investigation began with a deceptively simple behavioral question: given a choice, do mosquitoes prefer well-fed or undernourished hosts? Using controlled dietary restriction in laboratory mice, the researchers ran paired preference assays with multiple medically important mosquito species and found a consistent and striking result. Female mosquitoes preferentially oriented toward and fed on the undernourished animals. Because host-seeking in mosquitoes is governed by a layered integration of sensory cues, including carbon dioxide, heat, humidity, vision, and above all odor, the team reasoned that nutritional status might be altering the volatile chemical signature that hosts emit into the air. Behavioral experiments in which cues were selectively masked or manipulated confirmed that the differential attraction was olfactory in nature, pointing the investigators toward the skin surface as the source of the signal.

Gas chromatography-mass spectrometry analysis of volatile emissions from the skin of undernourished mice revealed a specific chemical culprit: elevated levels of volatile aldehydes. When these aldehydes were presented to mosquitoes in isolation or applied to otherwise unattractive hosts, they acted as potent attractants, reproducing the preference pattern observed with live undernourished animals. The aldehydes were not produced by the hosts themselves. Instead, they emerged from an unexpected intermediate player, the community of commensal bacteria that colonizes the skin. Sequencing and culture-based analyses showed that undernutrition was associated with a marked dysbiosis of the skin microbiota, with certain bacterial taxa proliferating to excessive densities and shifting their metabolic output toward aldehyde production. In effect, the mosquito-attractive odor was a microbial byproduct, released in greater quantities whenever the host’s nutritional state deteriorated.

The next question was mechanistic: why would a poor diet destabilize the skin microbiome in the first place? The answer lay in the dermal sebaceous glands, the microscopic structures that secrete sebum, a lipid-rich film coating the outer skin. The researchers found that undernutrition impaired the secretion of free fatty acids from these glands. Free fatty acids are not merely structural components of the skin barrier; they possess well-documented antimicrobial activity, suppressing the overgrowth of bacteria on the surface. With fatty acid output diminished, this chemical shield weakened, and commensal skin bacteria expanded unchecked. The team demonstrated this causal chain experimentally: restoring antimicrobial fatty acids, or reducing bacterial loads with antibiotics, both reversed the microbiota expansion and abolished the excess aldehyde emissions, thereby eliminating the heightened attractiveness of undernourished mice to mosquitoes.

To rule out confounding factors such as fur and general husbandry, the researchers extended their experiments to SKH1 hairless mice, in which skin surface chemistry can be sampled directly. The same pattern held. Undernutrition drove sebaceous dysfunction, skin bacterial overgrowth, dysbiosis, elevated aldehyde production, and increased mosquito attraction, providing a clean replication of the mechanism in a model system where the skin itself is fully accessible to analysis. The authors also showed that the effect operates in both directions of the transmission cycle. Undernourished mice were not only more likely to be bitten; they were also more susceptible to infection with dengue virus (DENV), developing higher viral loads. When mosquitoes fed on these viremic, undernourished hosts, the insects acquired virus more efficiently, and when infected mosquitoes subsequently fed, transmission onward was enhanced.

This dual effect, increasing both the probability that a host infects a mosquito and the probability that an infected mosquito infects a host, is what gives the finding its epidemiological weight. Vector-borne pathogens depend on a chain of events, each of which carries a probability, and interventions that raise or lower any single link can have outsized effects on the reproduction of an epidemic. By strengthening two links at once, host attractiveness and host infectivity, undernutrition may function as a critical modulator of transmission efficacy at the population level. The researchers present a model in which the prevalence of undernourished individuals within a community critically shapes the intensity of arbovirus circulation, a proposition with obvious implications for the geography of disease burden.

The human relevance of the mechanism was tested directly. In a cohort of undernourished human subjects, the team documented skin microbiota alterations mirroring those seen in mice, alongside elevated emission of volatile aldehydes from the skin. In behavioral assays, undernourished participants were more attractive to mosquitoes than their well-nourished counterparts. These converging lines of evidence, spanning rodent models, chemical analytics, microbiology, and human physiology, elevate the study beyond a correlation and support a coherent biological narrative: caloric and nutritional insufficiency suppresses sebaceous antimicrobial output, permits bacterial overgrowth, changes the skin’s volatile signature, and rewires the chemical conversation between humans and mosquitoes.

The broader context is sobering. Undernutrition and mosquito-borne disease overlap extensively across the tropics and subtropics, where food insecurity, poverty, and endemic dengue, malaria, Zika, and other arboviruses co-occur. Earlier work from the same field had established that host nutritional status can influence arbovirus virulence and evolution, and that host serum iron modulates dengue virus acquisition by mosquitoes, indicating that diet intersects with vector-borne transmission at multiple physiological levels. The new study adds skin chemistry and microbiota to this list and identifies a targetable axis. If aldehyde emissions and bacterial overgrowth mediate the effect, then interventions that restore sebaceous antimicrobial lipids, modulate the skin microbiome, or neutralize aldehyde cues could, in principle, reduce the excess bite risk borne by malnourished individuals, complementing bed nets, repellents, and vaccines.

For public health planners, the message is that nutritional support programs may double as disease control programs. Addressing undernutrition in regions where mosquito-borne pathogens are endemic would not only alleviate the direct morbidity and mortality of deficiency itself, but could also dampen the transmission cycles that keep those pathogens circulating. The authors argue that undernutrition should be recognized as a key driver of mosquito-borne disease transmission in nature, a reframing that places nutrition squarely within the toolkit of vector-borne disease control. As climate change expands the range of Aedes and Anopheles vectors and as food insecurity persists or worsens in many endemic regions, understanding and disrupting the metabolic link between diet, skin microbiota, and mosquito behavior may prove essential to bending the curves of some of the world’s most persistent epidemics.

Subject of Research: How undernutrition increases host attractiveness to mosquitoes and promotes the transmission of mosquito-borne diseases through skin microbiota changes.

Article Title: Undernutrition enhances host attractiveness to mosquitoes and transmission of mosquito-borne diseases

Article References: Wang, M., Song, X., Zhu, Y., Niu, J., Wang, G., Wang, Y., Xiao, H., Lei, D., Wu, T., Liu, L., Wang, P., Wang, J., & Cheng, G. (2026). Undernutrition enhances host attractiveness to mosquitoes and transmission of mosquito-borne diseases. Cell Research. https://doi.org/10.1038/s41422-026-01291-z

Image Credits: AI Generated

DOI: 10.1038/s41422-026-01291-z

Keywords: undernutrition, mosquito-borne diseases, dengue virus, skin microbiota, volatile aldehydes, sebaceous glands, fatty acids, host-seeking behavior, arboviruses, vector biology, malnutrition, disease transmission