The next breakthrough antibiotic might already be living on your face. That’s the intriguing conclusion from new research published in Current Biology, which reveals that a common skin-dwelling fungus could be a powerful ally in the fight against antibiotic-resistant bacteria. Scientists have identified a compound produced by Malassezia, a naturally occurring fungus found on human skin, that appears to effectively kill harmful strains of Staphylococcus aureus—including those responsible for serious infections in hospitals.
This unexpected find emerged from a collaboration between microbiologists at the University of Oregon and the University of California, San Diego. The researchers were exploring how the skin microbiome might regulate itself, and their focus landed on Malassezia sympodialis, a yeast that typically lives on our face, scalp, and upper body. It turns out this seemingly ordinary fungus is capable of producing a compound called 10-hydroxy-octadecanoic acid, or 10-HOA, which shows potent antibacterial properties—especially in conditions that mimic the natural acidity of human skin.
A natural defence system hiding in plain sight
What makes this discovery particularly promising is the specificity and efficiency of the compound. According to the researchers, when 10-HOA was applied to cultures of Staphylococcus aureus, it caused the bacterial cells to break apart, effectively bursting them open within a matter of hours. The effect was especially pronounced under acidic conditions—precisely the kind of environment found on healthy human skin. This pH-dependence might explain why the compound’s antibiotic activity was overlooked in earlier studies that used neutral or basic laboratory settings.
The team ran a series of controlled lab experiments using skin-like conditions and found that 10-HOA significantly reduced the number of viable S. aureus cells, without harming the beneficial or neutral microbes that also live on the skin. This suggests a promising future for the compound as a topical treatment for skin infections, including those that don’t respond well to conventional antibiotics.
Lead author Caitlin Kowalski explained in an interview that this discovery could shift how we think about the body’s natural microbial defences. Rather than being passive passengers, many of the fungi and bacteria on our skin might actively protect us against harmful intruders. As the study outlines, the skin is not just a physical barrier—it’s a chemically active ecosystem, teeming with microbial interactions that influence health in ways we’re only beginning to understand.
Fighting superbugs with what we already have
One of the most urgent problems in modern medicine is the rise of antibiotic resistance. The World Health Organization has repeatedly warned that we’re approaching a post-antibiotic era, where common infections could become untreatable. Drug-resistant strains of Staphylococcus aureus, especially methicillin-resistant S. aureus (MRSA), are responsible for hundreds of thousands of hospitalisations each year and contribute significantly to global mortality.
Against this backdrop, the discovery of 10-HOA is especially timely. According to the researchers, not only does it show effectiveness against S. aureus, but it also appears to spare less harmful skin microbes. This kind of targeted action is a rare trait among antibiotics and could make it easier to develop treatments that support the skin’s natural balance rather than disrupting it.
But there are still hurdles. While S. aureus was found to be vulnerable to 10-HOA, the bacteria did eventually develop resistance during long-term lab exposure. In those resistant strains, the mutation appeared in a gene involved in membrane stability and stress response, indicating that the bacteria were adapting to withstand the physical damage caused by the compound. This underlines an important lesson: no antibiotic is immune to resistance.
That said, researchers argue that the resistance observed here may not render the compound useless. Instead, it provides valuable insight into how 10-HOA operates and how it could be used in a therapeutic context. Future treatments might combine 10-HOA with other antimicrobial agents, or use it in short-term, targeted applications to reduce the risk of resistance developing.
This isn’t the first time fungi have played a major role in drug development. The antibiotic era itself began with penicillin, famously derived from Penicillium mould. More recently, fungi have been explored for their antifungal and antiviral properties, with one 2023 review highlighting just how many of these organisms produce natural compounds with medicinal potential. Yet, the idea that our own microbiome could be hiding antibiotic solutions is still a relatively new and exciting frontier.
Researchers involved in the Current Biology study believe that there may be many more such compounds waiting to be discovered—especially if future experiments are designed to replicate real human conditions like skin pH, temperature, and moisture. This study was one of the first to systematically investigate the biochemical interactions between skin fungi and bacteria using these more accurate models, and the results suggest we’ve barely scratched the surface.
There’s also interest in whether related fungi on other parts of the body might be producing different kinds of antimicrobial compounds. If Malassezia sympodialis makes 10-HOA, what might its cousins be doing? And could this discovery help explain why certain people seem more susceptible to skin infections, while others go years without even a spot?
More research will be needed before 10-HOA finds its way into pharmacies, but the groundwork has been laid. The next step will likely involve clinical trials to test the compound’s safety and efficacy in humans, particularly those with chronic skin conditions like eczema or infected wounds. There’s also the question of how to synthesise the compound at scale—researchers are currently exploring whether engineered strains of yeast or bacteria could produce it in larger quantities for medical use.
Still, the core message is one of optimism. Even as the world faces down a growing antibiotic resistance crisis, nature might already be offering solutions. And sometimes, those solutions are literally under our noses.
As Kowalski and her team point out, this discovery doesn’t just open the door to new treatments—it shifts our perspective on the skin microbiome entirely. We’re not just covered in microbes; we’re in a constant, often invisible, conversation with them. And it’s in that dialogue, not just in petri dishes, that the future of medicine might lie.