How Oysters Can Help Solve One of Medicine’s Biggest Problems

Between COVID-19, RSV, norovirus, and the flu, there is no shortage of illnesses circulating daily. Most ailments can be treated with medication, but what happens when bacteria, fungi, and other pathogens become resistant to conventional treatments? It’s a concerning issue, but a recent study published in PLOS One found a promising solution: oyster blood. 

The 2025 study revealed that antimicrobial proteins found in the blood (hemolymph) of Sydney rock oysters can eliminate specific bacteria and slightly increase the effectiveness of conventional antibiotics. 

Researchers extracted proteins from oyster blood and tested their efficacy against several types of bacteria, particularly those causing respiratory infections and becoming increasingly resistant to conventional antibiotics — commonly known as drug-resistant superbugs. They then discovered that when combined with standard antibiotics, these oyster proteins enhanced antibiotic effectiveness by up to 32 times. 

Researchers also confirmed that these proteins were not toxic to human cells, suggesting they may be safe for potential therapeutic use, says Daniel Rhoads, MD, chair of the College of American Pathologists Microbiology Committee. 

“Oysters have evolved remarkable immune defenses as a matter of survival in their challenging environments because they live in coastal waters teeming with bacteria, viruses, and parasites, but can’t rely on antibodies or adaptive immunity like humans do, since they don’t have a sophisticated immune system,” says Angelo Falcone, MD, an integrative medicine physician and founder of Dignity Integrative Health and Wellness. Instead, oysters have developed robust immune responses, including antimicrobial proteins that provide an arsenal of compounds working through various mechanisms to neutralize pathogenic threats, he explains. 

Here’s everything you need to know about the power of oyster blood and how it fights drug-resistant superbugs.

What are drug-resistant superbugs?

The term “drug-resistant superbug” is somewhat non-specific; however, it refers to bacteria that have developed the ability to endure antibiotics that once effectively eliminated or halted their growth, according to Falcone. 

“Think of them as bacteria that have developed armor against our medical weapons,” he says. “They’ve learned to neutralize antibiotics, pump them out of their cells, or modify their structures so antibiotics can’t recognize them anymore, but what makes them truly dangerous is that infections caused by these superbugs often don’t respond to standard treatments, leaving doctors with fewer — and sometimes no — effective options.”

Some of the most concerning drug-resistant superbugs include methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, and extensively drug-resistant tuberculosisHowever, more of these microbes are developing over time, posing a serious threat to human health, Rhoads says. “When microorganisms can grow in the presence of an antibiotic instead of having its growth inhibited, the microbe is described as being ‘resistant’ to the intended effect of the antibiotic, and these infections can lead to longer hospital stays, more complications, and higher mortality,” he explains.

Another way to think about it is that drug-resistant superbugs evolve through the survival of the fittest. “When we use antibiotics, we kill susceptible bacteria, but bacteria with random mutations that provide even slight protection can survive,” Falcone explains. “These survivors then multiply, passing their resistance genes to offspring, and what accelerates this natural process is our overuse and misuse of antibiotics, such as using antibiotics when they’re not needed, not finishing prescribed courses, or using broad-spectrum antibiotics when targeted ones would suffice.”

How does oyster blood fight drug-resistant superbugs?

Oyster blood contains specialized proteins that combat bacteria through mechanisms distinctly different from conventional antibiotics. “The study identified several potential active proteins, with ‘cystatin B-like protein’ being the most promising candidate, and these proteins likely work by inhibiting essential bacterial enzymes or disrupting bacterial cell membranes, essentially poking holes in bacterial defenses,” Falcone says.

These proteins are particularly valuable due to their ability to enhance conventional antibiotics through synergistic action, which occurs when the combination of two or more drugs produces a greater effect than that of each drug alone. 

“When combined with antibiotics, oyster proteins may help antibiotics penetrate bacterial defenses more effectively, allowing lower doses to achieve the same bacteria-killing effect,” Falcone says. The proteins also penetrate bacterial biofilms — the protective slime layers formed by bacteria, which typically shield them from antibiotics and host immune defenses — allowing antibiotics easier access to the bacteria to do their work, Rhoads adds. 

Oyster extract alone wasn’t effective against bacteria like Staphylococcus aureus, but it did dramatically enhance the effectiveness of conventional antibiotics against harder-to-kill species, according to Falcone. For instance, when antibiotics were combined with oyster extract, they were up to 32 times more effective against bacteria like Pseudomonas aeruginosa and Klebsiella pneumoniae, which are notoriously resistant to multiple drugs. 

Additionally, Falcone says that oyster blood extract exhibited significant activity against Streptococcus bacteria (even when the bacteria were embedded in biofilms), including various strains of Streptococcus pneumoniae, which are responsible for pneumonia, meningitis, and ear infections.

How can you reap the benefits of oyster blood?

Unfortunately, consuming more Sydney rock oysters won’t provide antimicrobial benefits because the active proteins will be digested in your stomach before they have a chance to work against infections, says Falcone. 

Instead, researchers are developing oyster proteins as potential pharmaceutical products and antimicrobial peptide medications, which may be administered either as inhalation therapy for respiratory infections or as an injectable drug alongside antibiotics, he says. These proteins could also be formulated as a topical treatment for skin infections or wounds. 

This study marks the initial phase in exploring the potential of an oyster byproduct for human therapy. Rhoads says that the development process will probably require years of further research, safety testing, and clinical trials before any product can reach the market. In the meantime, keep following this promising research. 

“What I find particularly exciting about this study is how it represents a shift in our approach to fighting superbugs, because rather than simply developing new versions of existing antibiotics — a strategy bacteria quickly adapt to — we’re exploring entirely different mechanisms of action inspired by nature,” Falcone says. “We shouldn’t expect oyster-derived antibiotics on pharmacy shelves tomorrow, but this research opens promising new avenues in our ongoing battle against antibiotic resistance, which is a crisis that demands exactly this kind of innovative thinking.”