Most antimicrobial approaches to the mouth work like a blunt instrument. Mouthwashes, antibiotics, and radiation reduce harmful organisms but also eliminate beneficial ones. In cancer patients, that collateral damage is a recognized problem because radiation disrupts the healthy oral microbiota and can allow pathogenic yeast to expand.
Which is why the most consequential detail in a University of Pennsylvania chewing gum study is not the headline percentage. It is what the gum left alone.
