Salivary mucin glycopolymers reduce virulence traits of cavity-causing Streptococcus mutans

Dry mouth is a condition characterized by an underproduction of saliva that affects one in five American adults. This reduction in salivary mucus is associated with higher incidences of cavities, oral ulcers, and microbial infections in the mouth. Saliva’s protective effects are derived from mucins, gel-forming proteins. These natural brush polymers display over two-hundred unique glycan motifs. Reconstituted salivary mucin gels have been shown to prevent biofilm formation of Streptococcus mutans, bacteria whose adherence to teeth causes cavities. Here, we show that mucin affects other virulence behaviors of these bacteria, reducing population-level signaling and gene transfer, which can spread antibiotic resistance. This evidence points to mucin gels’ unique ability to regulate the phenotypes of potentially pathogenic microbes. We also present our continuing efforts to design synthetic mucin-mimetic glycopolymers and test their efficacy at reducing microbial virulence. We hope that these principles can be used to develop mucin-inspired therapeutic polymers that could potentially alleviate the severity of dry mouth related symptoms based off of saliva’s natural protection mechanisms.