On Wednesday, a team of German microbiologists unveiled a new kind of antibiotic from an unlikely source: bacteria that call the human body home. Got questions about how they sniffed out the discovery? Here’s everything you need to know.

The team found a first-of-its-kind antibiotic, called lugdunin, that’s extremely effective against the bacterium Staphylococcus aureus, which can be resistant to many common antibiotics and can cause serious infections. For instance, Staphylococcus aureus is the species behind the notorious MRSA infections.

And, as the team points out in Nature, the drugmaker is all-natural: A bacterium called Staphylococcus lugdunensis secretes the antibiotic.

Here’s the cool part: S. lugdunensis lives in the human nose.

Well, technically, they weren’t looking in their noses. They were looking