In spring 2023, Egon Bech Hansen received an eagerly anticipated package of nine plastic plates, each with 3,456 small wells. Specifically, each well contained 0.1 microliters of an approved pharmaceutical, and these plates were intended to aid Egon Bech Hansen in conducting experiments to explore the unexpected connection between buttermilk and its potential to combat flesh-eating bacteria.

Yorgurt bacteria related to bacteria that causes illnesses

Breakfast yogurt contains beneficial probiotic bacteria known as Streptococcus thermophilus, which is related to Streptococcus pyogenes, the bacteria responsible for illnesses like sore throat, impetigo, erysipelas, and scarlet fever. Streptococcus pyogenes can become invasive, entering the bloodstream and producing toxins that cause blood clots and tissue necrosis, earning it the nickname “flesh-eating bacteria.” While this infection is rare, it can progress rapidly, destroying 5–10 centimeters of tissue per hour and posing a life-threatening risk.

The treatment for flesh-eating streptococcus infection involves administering high doses of antimicrobial drugs through the bloodstream or performing surgical removal of necrotic tissue. In severe cases, amputation of limbs may be required to stop the infection from spreading. Unfortunately, the fatality rate for this infection is as high as 25%.

Bacteria enzyme that acidifies milk similar to flesh eating bacteria

Egon Bech Hansen, a Professor at DTU Food, was surprised to find that an enzyme used by lactic acid bacteria to acidify milk was similar to an enzyme used by flesh-eating bacteria to deactivate the immune system. He discovered this similarity when he modeled the structure of the enzyme from a buttermilk bacterium. Although others had noticed this similarity before, no one had developed a method to combat flesh-eating bacteria using this knowledge.

A protease enzyme on the surface of streptococcal bacteria aids in breaking down proteins. In yogurt, this enzyme cuts milk proteins, facilitating bacterial growth and milk sugar conversion to lactic acid. Group A streptococcus employs a similar enzyme to sever immune system signaling molecules, evading immune cell detection. This renders the bacteria invisible to the body, allowing them to damage tissues without immune system interference.