UK - Household environment at the micro level may play a role in oral health

LONDON, UK: The role of the household may have an influence not only at the social level, but also at the microbe level. In a study conducted in the UK, researchers have discovered that early environmental influences are far more significant than human genetics in shaping the salivary microbiome, the group of organisms that determine oral and overall health.

Dr Adam P. Roberts, senior lecturer in antimicrobial chemotherapy and resistance at the Liverpool School of Tropical Medicine, pointed to periodontitis, which is associated with an altered microbiome, as a key example of how the study may be relevant to people’s oral and general health. “Once we understand the members of the microbiome that are responsible for health, our everyday behaviour could change to shift our microbiome favourably,” he said. Roberts co-led the study, which was conducted during his time at the UCL Eastman Dental Institute in London.

The study’s main objective was to discover how the salivary microbiome is established and what factors are most responsible for the mix of bacteria. With access to a unique sample set of DNA and saliva from an Ashkenazi Jewish family living in various households spread across four cities on three continents, the team asked how much of the variation seen in salivary microbiomes was due to host genetics and how much to the environment.

Owing to the family members adhering to ultra-Orthodox Judaism, they shared cultural diets and lifestyles that controlled for many confounding factors. Additionally, because the family members’ DNA had already been sequenced to the level of single changes in the DNA code, the research team had a unique and precise measurement of their genetic relatedness.

From this, UCL Genetics Institute graduate student Liam Shaw and the team of researchers sequenced the bacterial DNA signatures present in saliva samples from 157 family members and 27 unrelated Ashkenazi Jewish controls. Across all samples, they found that the core salivary microbiome was made up of bacteria from the Streptococcus, Rothia, Neisseria and Prevotella genera. “What that tells us is that the contact and sharing of microbes that goes on at the very local environment is what determines the differences between individuals,” said Shaw...............