Putting an end to antibiotic use on poultry farms by breeding super chickens could help.

Some chickens are naturally better at fighting off dangerous bacteria than others. And now that scientists have found a way to identify those birds, the production of flocks of super chickens—and a safer food system as a result—could be imminent.

Researchers at the US Department of Agriculture were able to identify roosters with strong immune systems by testing to see which ones had naturally high levels of two particular chemicals in their blood: cytokines and chemokines. Those chemicals, when released, effectively operate as sentinels in the body, by (among other things) alerting white blood cells as to where malignant invaders are located. They mobilize the birds’ immune systems, and birds with high levels of these chemicals have an increased ability to ward off dangerous pathogens.

With that knowledge, commercial breeders—already masters of selective breeding—will be able to test and single out birds for their immune-system strength, then breed whole flocks of them. That could be a huge boon to public health, and could save billions of dollars along the way.

Consider campylobacter, just one of the many dangerous foodborne pathogens that threaten human health every year. This bacterial infection affects an estimated 1.3 million people annually in the US. Once it infects a person, it can cause diarrhea, fever, and in some rare cases, life-threatening illness. It typically lives in the intestinal tracts and livers of chickens and cows, and can spread to humans through meat produced in slaughter facilities or through crops that have come into contact with soil fertilized with animal feces. Public health officials estimate the overall economic burden of the bacteria hovers around $2 billion each year.

The bacteria has grown increasingly resistant to antibiotics, in part, because of how regularly farmers feed their animals antibiotics to prevent illness. The medicines were designed as tools for treatment, not prevention. But public backlash to the overuse of antibiotics on farms has food producers, including the poultry industry, looking for alternatives. The scientists behind this new research, first published in the journal Poultry Science, say birds with stronger immune systems would likely have fewer pathogens physically on their bodies as they enter slaughter facilities. And if that’s the case, it could mean a safer food product on grocery-store shelves.