The findings show that "bacteria have a very important role to play in our immune defence," said Richard Gallo from the University of California, San Diego.
Researchers looked at patients with eczema, a condition which causes itchy, red, inflamed skin. They found that the patients who had persistent eczema tended to be deficient in the friendly bacteria that kill a type of bacteria called Staphylococcus aureus. In contrast, people without eczema have an abundance of the helpful bacteria.
The researchers swabbed the patients' skin, and cultured the few friendly strains of bacteria they could find. They grew more of these bacteria in the lab, and added the microbes to a lotion. They had the patients apply their own personalised microbe-containing lotion to one arm and regular moisturiser to the other.
After 24 hours, in all five patients, only the arms treated with the microbe-containing lotion showed near total improvement, and in two patients, the staph pathogens were destroyed entirely. The study was published in the journal Science Translational Medicine.