Pearl ‘blood’ may hold key to ‘imminent’ health crisis

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

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

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

Growing superbugs

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

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

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

Researchers at Southern Cross University believe Sydney’s 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’re 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 a previous study, the team found that the protein found in hemolymph (aka oyster blood) was effective in killing Streptococcus pneumoniae and Streptococcus pyogenes, the bacteria responsible for pneumonia and strep, respectively.

Normally, bacteria evade antibiotics and the immune system by forming clusters called biofilms, which are enclosed in a sticky, protective coating.

The 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 laboratory tests, oyster protein increased the effectiveness of antibiotics against a variety of dangerous respiratory pathogens by up to 32 times.

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

Most importantly, the researchers said the oyster hemolymph protein was not toxic to healthy human cells, suggesting it could one day be used to develop natural products to treat bacterial infections. However, they cautioned that further study is needed in animals and humans.

“Meanwhile, oysters can help keep breathing bugs away,” Benkendorff said. “Osticas contain zinc, which strengthens the immune system, and they have polyunsaturated fatty acids and really good vitamins that also help modulate immunity.”

Clams 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 is no scientific evidence that oysters increase libido, they have long been considered a natural aphrodisiac.