The Wall Street Journal reports that scientists at Pennsylvania State University and the University of Adelaide, in Australia, are working on a novel method to fight tooth decay. Different bacteria in the mouth can cause oral disease or prevent it, and the idea is to transfer bacteria from the mouth of a healthy individual to reduce tooth decay in another.

The researchers identified an individual that brushes only once a day, never flosses and has no cavities despite having not visited the dentist in five years. This super donor’s microbiome was so healthy that poor oral hygiene habits did not seem to matter. When the scientists applied plaque from the super donor to the teeth of rats, the animal subjects showed a significant drop in tooth decay. Clinical trials on humans will begin later this year.