New research indicates that arginine, an amino acid that is already present in saliva, helps protect enamel and prevent cavities.
The key to preventing tooth decay may already be present in the human mouth. A new clinical study suggests that increasing levels of arginine amino acid in saliva can transform harmful bacterial biofilms into a more protective state, reducing the acidity that leads to cavity formation.
Tooth decay not caused directly by sugarbut rather by the bacteria that feed on it. These microorganisms metabolize sugars and release acids that gradually erode tooth enamel. Over time, dense bacterial biofilms form on the surface of the tooth, which can trap acid against the enamel and accelerate decay.
A new published in The International Journal of Oral Science reveals that arginine, an amino acid naturally present in saliva, can change this process. In people with active cavities, regular exposure to arginine reduced the acidity of bacterial biofilms, altering both the microbial composition and the sugars present in these biofilms, explains .
“Our results revealed clear differences in acidity, with biofilms treated with arginine showing a significantly greater protection against acidification caused by sugar metabolism,” said Yumi Del Rey, a microbiologist involved in the study.
While previous laboratory studies have suggested that arginine may help prevent cavities, the new research aimed to test its effects in real human mouths. Ten participants with active tooth decay participated in the study. Each wore dentures with small panels that allowed the natural formation of bacterial biofilms over four days.
Three times a day, the prostheses were removed and treated. The biofilms were initially exposed to a sucrose solution to simulate sugar ingestion. One side of each prosthesis was then treated with an arginine solution, while the other side was rinsed with distilled water as a control.
After four days, the researchers analyzed the biofilms in detail. When exposed to sugar again, the arginine-treated biofilms consistently maintained a higher pH level, meaning they were less acidic and less likely to damage enamel.
Additional analysis revealed that arginine treatment altered both the sugars and bacteria within the biofilms. Levels of the sugar fucose were lower, while galactose was more concentrated in the outer layers of the biofilm, away from the tooth surface. DNA analysis also showed a reduction of bacteria Streptococcus acid-producing bacteria and a slight increase in bacteria capable of metabolizing arginine.
The researchers noted that responses varied between individuals and that not all participants experienced the same level of benefit. The reasons for this variability remain unknown.
Despite open questions, the findings suggest that arginine may be a promising addition to toothpastes or mouthwashes.
