Mouth Microbes Are All the Talk in Rochester This Week

Jun. 12, 2011
S. mutans

Scientists from around the nation will come to the University of Rochester Medical Center this week to trade data and swap the latest insights about the activities of hundreds of species of microbes that live, thrive, reproduce, jockey for a foothold, and die – all in our mouth.

The conference, hosted by the Center for Oral Biology, focuses on the “oral microbiome” – the genetics of all the microbes that take up residence in our mouths. The meeting brings together approximately 100 scientists from around the world who are making it their business to take a collective look at the organisms that live in our oral cavity and figure out ways to understand their genes in ways that will improve our health.

The conference takes place this Thursday through Saturday, June 16-18, at the Medical Center.

“We’re bringing together people who have made it their lives’ work to understand the members of these microbial communities,” said Robert Quivey, Ph.D., Dean’s Professor of Microbiology and Immunology and director of the Center for Oral Biology. “The long-term goal is to improve human health, perhaps by understanding why some people are more susceptible to certain diseases than others.”

The meeting dovetails with a nationwide effort launched in 2008 known as the NIH Human Microbiome Project, which aims to learn more about the genetics of the microbes found at five different sites in the human body: the nasal passages, the oral cavity, the skin, the gastrointestinal tract, and the urogenital tract. Scientists around the nation are studying microbes collected from thousands of healthy people and unraveling their DNA sequences in the effort to learn how these microbes play a role in our health and in diseases we develop.

Many people are familiar with the Human Genome Project, which has decoded the basic human DNA sequence. Not far behind are efforts to understand the genomes of a variety of other creatures – scientists have deciphered the genetic codes of dozens of species, including certain fish, worms, bacteria, flowers, dogs, fruit flies, and rats.

In Rochester this week, the focus will be on the genes of organisms that make their home on the teeth, the tongue, the gums, and the rest of the human oral cavity.

The scientists have their work cut out for them: Collectively, the species in our mouths likely have more than 2 million genes, perhaps many more, all composed of billions of base pairs of DNA.

“We’ve learned that there are more than 500 and probably less than 1,000 species that live in our mouths,” said Quivey. “Now we need to find out how all those organisms – each with a different set of genes – survive in our mouths, and how they interact, and what their role is both when we’re healthy and when we’re ill. In some cases, perhaps we can learn to tip the balance so that we can boost the balance of good bacteria, and keep at bay the bad bacteria that make people prone to disease.”

Scientists will discuss new ways to try to bring down the molecular fortresses that bacteria build in our mouths, ultimately allowing them to rot our teeth; whether some bacteria make people more prone to developing throat cancer; why normally good bacteria in the mouth sometimes go bad, causing life-threatening illnesses; and how bacteria in the mouth signal each other to form communities that sometimes harm us and sometimes help us.

Quivey himself is studying Streptococcus mutans, the bacteria responsible for forming the majority of cavities. S. mutans lives in our mouths, munches on our food, and then churns out acid that destroys our teeth. The bacterium has adapted to this environment, thriving while literally sitting in its own acidic juices.

Quivey’s team is carrying out an unprecedented analysis of s. mutans’ 1,963 genes, creating hundreds of mutant strains by knocking out each gene, one by one, and then studying the effects. One goal is to learn exactly how s. mutans protects itself against acid, then disarm the bacterium so it destroys itself before harming our teeth.

The entity pulling the conference together – the Center for Oral Biology – has a long history of being at the forefront of dental research nationally. Rochester has played a leading role in understanding how fluoride protects teeth, for instance, and has demonstrated that the presence of low levels of fluoride in the mouth can help prevent cavities in children. Rochester dentists also developed ways to make dental sealants better adhere to tooth surfaces. These developments have helped reduce cavities worldwide dramatically. Currently the center is among the five top-funded research programs supported by the National Institute of Dental and Craniofacial Research.

The center is part of the Medical Center’s Eastman Institute for Oral Health, a world leader in research and post-doctoral education in general and pediatric dentistry, orthodontics, periodontics, prosthodontics, and oral surgery. 

This week’s conference is supported in part by Colgate-Palmolive Co., Wrigley, Applied Biosystems/Ion Torrent, the National Institute for Dental and Craniofacial Research, and the University of Rochester.