Arginine, a natural amino acid in saliva, helps neutralize tooth-damaging acids and reshapes dental plaque to be less harmful. A clinical study found it reduces acidity, weakens plaque’s structure, and nudges mouth bacteria toward a healthier balance. Credit: Shutterstock When bacteria in the mouth break down sugars from food, they release acids that gradually erode tooth enamel and cause cavities. These bacteria do not live alone. They form dense, plaque-like structures known as "dental