Saint Louis University

Researchers at SLU's Center for Advanced Dental Education took samples from different areas of the oral cavity from healthy adults to learn more about the normal bacterial make-up of the mouth as a part of the National Institutes of Health's $173 million Human Microbiome Project.

D. Douglas Miley, DMD, director of periodontics and Nathalia Garcia, DDS, clinical professor of periodontics

Reports from the project's consortium members - made up of nearly 80 institutions and 200 individuals -- were published this week in Nature and Public Library of Science (PLoS) journals, providing a first look at the five year effort to catalogue the normal microbial make-up of healthy adults.

Samples from 15 body sites were collected from 242 study volunteers in the U.S. and then analyzed with DNA sequencing machines. Computers sorted through the data and used a bacterial marker to ignore human genome sequences and single out only bacterial DNA. Researchers report that more than 10,000 microbial species live in healthy humans.

At SLU, principal investigator and assistant clinical professor of periodontics Nathalia Garcia, DDS, and periodontics program director, D. Douglas Miley, DMD, collected specimens from multiple locations within the mouth, saliva, soft tissue and hard tissue sites.

From her vantage point in periodontics, Garcia says the information generated by the study will provide resources to enable comprehensive characterization of the human microbiota and analysis of their role in human health and disease.

"This new reference data is a very important tool to help us know what kind of microorganisms live in our mouths. Many oral diseases, like periodontitis, for example, are infectious diseases that will be better understood once we know about the normal microbial makeup of the mouth.

"The data provided by the Human Microbiome Project offers an important tool for the research community to continue its work."

Read more about the NIH's Human Microbiome Project here.