Compounds found in maple can inhibit the bacteria that cause cavities, according to a newly published study by University of Wyoming researchers.

The study, titled “Maple polyphenols inhibit sortase and drastically reduce Streptococcus mutans biofilms,” was published in the journal Microbiology Spectrum earlier this month.

Many oral health products include toxic ingredients. This new research may offer a safe, cost-effective direction for oral health products.

Postdoctoral researcher Ahmed Elbakush was the lead author of the study, along with professor of molecular biology Mark Gomelsky and doctoral student Oliver Trunschke.

Gomelsky has been studying Listeria monocytogenes, a deadly foodborne pathogen, for over a decade. His lab discovered that Listeria bacteria form a protective biofilm, a “shield” made of specialized sugar-based polymers. Biofilms can protect Listeria from dehydration and from chemicals that would otherwise kill the bacteria. Biofilms also allow the bacteria to cling to other bacteria or to surfaces, particularly plant matter like fresh produce.

While studying Listeria biofilms, Elbakush found that Listeria struggles to cling to maple wood, in contrast with other plant surfaces. This led to the discovery that certain natural compounds found in maple sap disrupt biofilm formation, preventing Listeria from clinging to plant surfaces and leaving it much more vulnerable to dehydration and disinfectants.

The recent study uncovered what part of the bacteria these compounds inhibit. These maple compounds target sortase A, a protein necessary for Listeria bacteria to form their protective biofilm and to cling to surfaces.

The UW researchers also identified the specific compounds in maple that inhibit sortase A. These compounds are known to be non-toxic, since they have been consumed for centuries in products like maple syrup and green tea. The newly published study reveals that one compound, epicatechin gallate or ECG, was especially effective at inhibiting sortase A.

Sortase A proteins are also present in Streptococcus mutans, a species of bacteria that causes cavities. S. mutans bacteria need sortase A to stick to teeth surfaces. If sortase A is inhibited, the bacteria cannot stick to teeth and therefore cannot cause cavities.

“After years of research, we have figured out what compounds in maple are active and what they target in Listeria,” says Gomelsky. “Once we understood that, we realized that other bacteria that are related to Listeria, like Streptococcus, have the same target protein, sortase A. So, we wondered whether we can prevent the bacteria that cause dental decay, Streptococcus mutans, from attaching to teeth just like we can prevent Listeria from attaching to fresh produce.”

Different people have different strains of S. mutans in their mouths. The natural compounds the researchers tested affect multiple strains of S. mutans, which suggests that the compounds can fight cavities in all people.

Research funding for the study was provided by the New Mexico Start-Up Factory, the National Institutes of Health (NIH), the National Institute of Food and Agriculture, and the University of Wyoming Seed Translational Acceleration of Research (STAR) Project.

For more information, contact Gomelsky at gomelsky@uwyo.edu or (307) 766-3522.