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News / December 15, 2010

Study may lead to personalised oral care

by Guy Hiscott

A new study into the bacterial immune system reveals that the defences of the oral microbiome are unique and traceable – which could lead to personalised oral health care.
Studies in the past have looked at viral communities of the respiratory and digestive tracts, suggesting viruses may influence the microbial eco-system and health of the human.

But less is known about the effect on the oral microbiome which could have significant implications for diseases of the oral cavity, according to this recent study.

David Pride, of the University of California and lead author of the report, says: ‘We knew that bacteria developed specific resistance to viruses. But before this study, we had no idea of the extent to which certain oral bacteria in humans have utilised these resistance mechanisms against viruses.’

The team of experts carried out the tests on four healthy subjects over the course of 17 months, by obtaining saliva samples from each and analysed specific bacterial DNA elements that confer acquired immunity against viral attack.

They then 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 7-22% – there was a large amount of change observed even in short periods.
David adds: ‘Each time we sampled our human subjects, approximately one-third of the immune repertoire in the bacterial community was new. Which suggests that the development of resistance to viruses is occurring at least on a daily basis, if not more frequently.’

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 the team suggests, could lead to more personalised 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 personalised oral health care, where lineages of microbes are traced as a part of routine health care for individuals,’ the study concludes.

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