We all know that one person who seems to be magically mosquito-free. No matter what they're doing, they just don't seem to get bitten, even when everyone around them is miserable. And then of course there's the opposite, the person who always seems to attract mosquitos. It's like they're a mosquito magnet––they could be absolutely covered in repellent, sitting next to a citronella candle, and the nasty little pests still seem to find them.
For years, myths have gone around about why some people seem to be mosquito-exempt and others seem to have a "Bite me!" sign stuck to their foreheads.
From the classic, "it's your blood type" and "it's because of your clothing" to the more metaphorical, "it's because you're so sweet!", the mosquito-plagued hear it all.
There is some truth to some of the rumors: mosquitos are attracted more to certain blood types than others, they love people who have been drinking, and they will definitely bite you more if you're wearing certain colors.1,2,3 But research shows that your mosquito-attractiveness may have much more to do with bacteria––specifically, that of your skin microbiome.
What's the Skin Microbiome?
Your skin microbiome is the ecosystem of bacteria that live on and in your skin. Similar to your gut microbiome, your skin microbiome is made up of a balance of mostly good bacteria, with a little less-hospitable bacteria mixed in. When your microbiome is in balance, your skin looks and feels good. When it's off, your complexion may not look its best.4
Your skin hosts more than 1,000 species of skin flora in any given spot. While that might sound like a bad thing––after all, we've been taught to think of bacteria as being something to get rid of––it's actually great! The more diverse your microbiome is, the better, since there's a much higher chance that the good bacteria will crowd out the bad.
Unfortunately, a lot of the things we do on a daily basis deplete the diversity of the skin microbiome, making it easier for inhospitable bacteria to thrive. Simple things like using harsh soaps that throw off your skin's pH, using skincare products that have lots of artificial chemicals in them, or using overly strong deodorants may seem normal, but in fact, they can devastate your bacterial populations.
That's Where Mosquitos Come In
Studies show that the types of bacteria that make up your skin microbiome may be the secret to why some people attract mosquitos, while others naturally repel them. Like many animals, mosquitos find their food sources based on scent. In the case of humans, we develop a unique scent signature based on the composition of our skin flora. While certain types of bacteria make for the type of smell we associate with body odor, others (like the mix typically found in a healthy, diverse skin microbiome) make for a much more subtle, pleasant smell.
That's all from a human perspective, of course––from the perspective of mosquitos, there's nothing more attractive than a low-diversity, high bacterial-count skin microbiome.
In one study, Dutch researchers had people avoid showering and using scented cosmetics for a couple of days, as well as stay away from foods that are known to repel mosquitos. They were trying to get at the subjects' natural skin microbiomes to see whether the composition of bacteria had an effect on the people's attractiveness to mosquitos.
When they exposed mosquitos to samples of sweat (containing millions of microbes) from the subjects, they found that the sweat from people who had more diverse skin microbiomes was much less attractive to mosquitos than that from those with less diverse bacterial ecosystems.5 What's more, people who were more attractive to mosquitos also had higher concentrations of certain types of bacteria, including Staphylococcus (most known for its role in antibiotic-resistance) and Pseudomonas, which can cause problems for people whose immune systems aren't working as they should.
Essentially, having a healthy skin microbiome acts as a kind of natural mosquito repellent.
While it's not the only factor at play when it comes to attracting mosquitos, it is an important one––and it can make all the difference if you've already been following advice on how to keep mosquitos away and are still getting bitten.
How to Help Keep Those Pesky Mosquitos Away
So what can you do to make sure that you stay covered in the good guys? Try these tips to support your skin microbiome:
1. Avoid over cleaning.
It takes a bit of a paradigm shift, but our modern, post-Industrial Revolution focus on hygiene isn't designed to work with how we developed as a species. Using cleansers, lotions, and deodorants that contain harsh chemicals dries your skin and strips it of all bacteria, not just the ones that cause odors and issues. This creates the perfect conditions for inhospitable bacteria to thrive, crowding out the good guys and creating a cycle in which you overclean to get rid of the bad bacteria, have them come back stronger, and then take even greater measures to get rid of them.
So do what you can to avoid stripping your skin of the good guys. This can include showering a little less often, switching to a natural deodorant, and avoiding products made with things that are hard on your skin (especially antibacterial ingredients!). If you're worried that your hygiene will start slipping, don't be––the more you cultivate good skin flora, the more you'll get that natural glow, and the lower the amount of odor-causing bacteria you'll have.
2. Consider using probiotic skincare.
Since it's nearly impossible to fully care for your skin flora in our modern lifestyle, consider supplementing them with probiotic skincare products. These are products that contain the good bacteria that keep you looking and smelling great. Applying them helps keep your skin microbiome in balance so you not only get your good skin flora's mosquito-repelling benefits, your skin will also look and feel wonderful.6
3. Spend some time outside.
Take advantage of your new, less mosquito-friendly state by spending some time in nature. Getting outside is a great way to increase the diversity of your skin microbiome, upping your chances of being naturally mosquito-repellent by giving you more good guys to crowd out the bad ones. Plus you'll get all the health benefits of being in nature, including greater diversity in your gut microbiome!
4. Use skin-friendly mosquito repellent.
While improving your skin flora will definitely make you less attractive to mosquitos, there are other things that might still be attracting them. For instance, mosquitos are much more attracted to pregnant women because of the amount of carbon dioxide they give off, as well as people wearing dark solids and big floral prints. Similarly, they're hugely attracted to the ethanol that your body gives off when you've been drinking, as well as people who have recently eaten a lot of sugary or salty foods and those who use AHA skin products, due to the lactic acid they contain.7,8
So if you do happen to have a couple of other factors working against you, by all means use a mosquito repellent; just make sure it's not going to mess up the healthy skin microbiome you've cultivated. Try applying essential oils instead of the more common chemical repellents: calendula, geranium, lavender, and citronella are all skin-friendly when diluted.
You may never be able to avoid mosquitos entirely, but at least now you won't be accidentally undermining your own efforts to avoid them. Try at least one of these steps to support your skin diversity––and in doing so you'll enjoy far more benefits than fewer bites!
References:
1. Shirai, Y., Funada, H., Seki, T., Morohashi, M., Kamimura, K. (2004). Landing Preference of Aedes Albopictus (Diptera: Culicidae) on Human Skin Among ABO Blood Groups, Secretors or Nonsecretors, and ABH antigens. Journal of Medical Entomology 41(4).
2. Shirai, O., Tsuda, T., Kitagawa, S., Naitoh, K., Seki, T., Kamimura, K., Morohashi, M. (2002). Alcohol Ingestion Stimulates Mosquito Attraction. Journal of the American Mosquito Control Association 18(2).
3. Onyett, H. (2014). Preventing Mosquito and Tick Bites: A Canadian Update. Paediatrics and Child Health 19(6). doi: 10.1093/pch/19.6.326
4. Arck, P., Handjiski, B., Hagen, E., Pincus, M. . . . Paus, R. 2010. Is There a Gut-Brain-Skin Axis? Experimental Dermatology 19. doi: 10.1111/j.1600-0625.2009.01060.x
5. Verhulst, N.O., Qiu, Y.T., Beijleveld, H., Maliepaard, C. Knights, D. . . .Smallegange, R.C. (2011). Composition of Human Skin Microbiota Affects Attractiveness to Malaria Mosquitoes. PLOSOne 6(12). doi: 10.1371/journal.pone.0028991.
6. Krutmann, J. 2009. Pre- and Probiotics for Human Skin. Journal of Dermatological Science 54(1). doi: 10.1016/j.jdermsci.2009.01.002
7. Lindsay, S., Ansell, J., Selman, C., Cox, V., Hamilton, K. Walraven, G. (2000). Effect of Pregnancy on Exposure to Malaria Mosquitoes. The Lancet 355(9219). doi: 10.1016/S0140-6736(00)02334-5
8. Acree, F, Turner, R.B., Gouck, H.K., Beroza, M., Smith, N. (1968). L-Lactic Acid: A Mosquito Attractant Isolated from Humans. Science 161(3848). doi: 10.1126/science.161.3848.1346.
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Rachel Allen is a writer at Hyperbiotics who's absolutely obsessed with learning about how our bodies work. She's fascinated by the latest research on bacteria and the role they play in health, and loves to help others learn about how probiotics can help the body get back in balance. For more ideas on how you can benefit from the power of probiotics and live healthier days, be sure to subscribe to our newsletter. To learn more about how a healthy microbiome can enrich your life, subscribe to our newsletter.