NPJ: Eliminating bacterial “noise” in the mouth helps prevent tooth decay

Interfering with the chemical “communication system” of oral bacteria can shift the composition of dental plaque toward a healthier state and prevent the development of tooth decay. This conclusion was reached by scientists from the University of Minnesota. The study was published in NPJ Biofilms and Microbiomes.

According to the researchers, bacteria in the oral cavity do not exist in isolation: they exchange signaling molecules through a mechanism known as quorum sensing. These chemical signals allow microbes to coordinate their behavior, regulate gene activity, and determine which species dominate within the bacterial community. This balance largely determines whether the microbiota remains in a “healthy” state or shifts toward tooth decay and gum disease.

The researchers studied laboratory models of dental plaque and focused on signaling molecules called N-acyl homoserine lactones (AHLs), which are used by certain bacteria. They found that specific enzymes can block these signals, effectively “silencing” bacterial communication.

Such interference reduced the activity of microbes associated with gum inflammation while simultaneously promoting the growth of bacteria characteristic of a healthy oral cavity.

As the authors explain, the formation of dental plaque resembles the development of an ecosystem. Initially, the surface is colonized by relatively harmless bacteria, but under unfavorable conditions more aggressive species appear, including Porphyromonas gingivalis, which is closely linked to periodontitis.

“By disrupting the chemical signals that bacteria use to communicate, it is possible to steer the dental plaque community toward a state associated with oral health,” notes the study’s author, biochemist Mikael Elias.