Australian oyster blood could be the secret to tackling a ‘looming global health crisis’

Slurping oysters may soon do more than just satisfy your seafood cravings. 

Australian scientists discovered a protein in the blood of Sydney rock oysters that not only kills bacteria but also boosts the power of conventional antibiotics.

The finding could be a game changer in the fight against antimicrobial resistance, which has been called a “looming global health crisis.”

Superbugs on the rise

Antimicrobial resistance occurs when bacteria and other germs evolve to become stronger than the antibiotics designed to kill them, often due to their overuse and misuse.

Infections caused by these so-called “superbugs” are tougher, if not impossible, to treat, claiming more than 1 million lives worldwide each year since 1990.

The situation is only expected to get worse. A 2024 study predicted that antibiotic-resistant infections could cause more than 39 million deaths by 2050 — three fatalities every minute — without intervention. 

Researchers at Southern Cross University believe that Sydney rock oysters could play a role in combating the growing health crisis.

Nature’s secret weapon

When developing new drugs, scientists often look to nature for inspiration, focusing on organisms with built-in defense mechanisms against infection. In fact, more than 90% of the antibiotics we rely on today come from natural sources.  

“Oysters are constantly filtering bacteria from the water, so they are a good place to look for potential antibiotics,” Kirsten Benkendorff, a study co-author and an interdisciplinary marine scientist at Southern Cross, said in a statement. 

In an earlier study, the team discovered that the protein found in hemolymph (aka oyster blood) was effective at killing Streptococcus pneumoniae and Streptococcus pyogenes, the bacteria responsible for pneumonia and strep throat, respectively. 

Normally, bacteria evades antibiotics and the immune system by forming clusters called biofilms, which encase themselves in a sticky, protective layer.

Researchers found that the oyster hemolymph protein helped block biofilm formation and could penetrate existing biofilms, allowing antibiotics to target the bacteria more effectively.

In lab tests, the oyster protein increased the effectiveness of antibiotics against a range of dangerous respiratory pathogens by as much as 32 times.

The results were particularly promising for Staphylococcus aureus (golden staph), a major cause of drug-resistant skin and bloodstream infections, and Pseudomonas aeruginosa, which poses a significant threat to immunocompromised patients with cystic fibrosis.

Importantly, researchers said the oyster hemolymph protein wasn’t toxic to healthy human cells, which suggests it could one day be used to develop natural products for treating bacterial infections. However, they cautioned that further study in animals and humans is needed. 

“In the meantime, slurping oysters could help keep the respiratory bugs away,” Benkendorff said. “Oysters contain zinc, which boosts the immune system, and they have really good polyunsaturated fatty acids and vitamins that also help modulate immunity.”

The slimy mollusks and their shells have long been a staple in traditional medicine to treat everything from inflammatory conditions and insomnia to high blood pressure and heart palpitations. 

And while there’s no scientific evidence that oysters increase sex drive, they’ve long been considered a natural aphrodisiac.