Morning routines can feel small until you picture what happens right after breakfast. Sugar hits your mouth. Bacteria in plaque go to work. They ferment those sugars and release acids that soften enamel. If those acid attacks repeat, cavities follow. A clinical trial from Aarhus University in Denmark suggests a simple helper already present in your body may blunt that acid drop. The helper is arginine, an amino acid found in saliva. In the study, arginine made dental biofilms less acidic after sugar, shifted their sticky carbohydrate makeup, and slightly reshaped which bacteria thrived. The work matters because it moves beyond lab dishes. It tests biofilms in real mouths, in people with active tooth decay. It also looks at plaque as it truly exists, layered, uneven, and full of tiny “hot spots” where acids can pool. Study design. (CREDIT: International Journal of Oral Science) Why Plaque Turns Sugar Into Tooth Damage Dental caries starts with chemistry. You carry many bacteria in your mouth. When sugars arrive, some bacteria ferment them and generate acids. Those acids …