Oral microbe study could lead to personalized oral care

13-Dec-2010 - Last updated on 13-Dec-2010 at 16:45 GMT

Related tags Bacteria

For the first time, a team of scientists have performed a study of a bacterial immune system in humans over time, finding that the defenses of the oral microbiome are unique and traceable, which could help personalize oral health care in the future.

Studies in the past have looked at viral communities of the respiratory and digestive tracts, suggesting viruses may influence the microbial ecosystem and health of the human host, however less is known about the effect on the oral microbiome, which could have significant implications for diseases of the oral cavity, according to the study.

"We knew that bacteria developed specific resistance to viruses," said David Pride of the University of California, and lead author of the report.

"But before this study, we had no idea of the extent to which certain oral bacteria in humans have utilized these resistance mechanisms against viruses.”

Tests carried out on ‘healthy’ subjects

Pride and his colleagues at the San Diego-based institution carried out the tests on four healthy subjects over the course of 17 months, by obtaining saliva samples from each and analyzed specific bacterial DNA elements that confer acquired immunity against viral attack (known as CRISPR), and sequenced them with corresponding streptococcal repeats.

The study of the CRISPR (clustered regularly interspaced short palindromic repeats) and spacer sequences revealed that although there is a set of CRISPR maintained in each subject over time, ranging from 7 to 22 percent, there was a large amount of change observed even in short periods.

"Each time we sampled our human subjects, approximately one-third of the immune repertoire in the bacterial community was new," Pride explained.

"Which suggests that the development of resistance to viruses is occurring at least on a daily basis, if not more frequently," he added.

Track and trace bacteria

There was also traceable bacterial immune repertoires found, meaning that the scientists should be able to track the system within each person and also track the bacteria passed between subjects, which Pride suggests, could lead to more personalized oral care.

"Because these immune features can be used to track bacteria and their respective viruses in humans, it may open to door to more personalized oral health care, where lineages of microbes are traced as a part of routine health care for individuals," he concluded.

The full study can be found in the latest issue of Genome Research (December 2010, 20 (12)) online at www.genome.org