Effect & Mechanism of Xylitol on Early Childhood Caries (Metagenomics) Study

Early childhood tooth decay or caries is often caused by bacteria on the teeth that release acids to dissolve the tooth.

These bacteria feed off the sugar or starch in the foods we eat.

In the past, researchers and dentists measured the levels of bacteria such as mutans streptococci (MS) to determine a person's risk for tooth decay.

However, different bacterial species have different properties.

Some species are more harmful and cause cavities.

Others are less damaging.

Predicting a person's risk for tooth decay by only assessing their MS bacteria levels is inadequate.

The purpose of the Effect & Mechanism of Xylitol on Early Childhood Caries (Metagenomics) Study is to identify the genes that cause tooth decay.

To do this, researchers will genetically sequence bacteria previously collected and processed from saliva and swab samples from children in three previous studies.

The first study compared MS bacteria in children with severe tooth decay against cavity-free children.

The second study was a randomized, controlled, clinical trial that compared children whose parents used xylitol wipes or regular wipes to clean their young children's teeth.

The third study collected swabs from inside the cheeks of children with and without cavities

Xylitol seems to influence the virulence of MS bacteria.

Researchers also plan to investigate the relationship between the microbial composition of MS bacteria and the bacterial genes associated with tooth decay.​

To do this, researchers will compare previously collected MS samples from children with cavities and from those without.

This approach has been impossible until now due to the high cost and difficulty of data analysis.

However, new, metagenomic techniques developed at UCSF have now made this method feasible.

Studying the genetic profile of microbes that cause tooth decay and the mechanisms by which xylitol acts to prevent tooth decay can help researchers identify those genes susceptible to disease and amenable to therapy.

These findings may aid in formulating new approaches toward the identification, diagnosis, prevention, and treatment of tooth decay.