The human mouth is home to a teeming community of microbes, yet still relatively little is known about what determines the specific types of microorganisms that live there. Is it your genes that decide who lives in the microbial village, or is it your environment? In a study published online in Genome Research (www.genome.org), researchers have shown that environment plays a much larger role in determining oral microbiota than expected, a finding that sheds new light on a major factor in oral health.
Our oral microbiome begins to take shape as soon as we are born and sees a myriad of bacteria introduced to our mouth during childhood and later in life, yet little is known about whether nature (your genes) or nurture (your environment) has a stronger influence. Because of variations in the oral microbiome in both health and diseases like bacteremia and endocarditis, understanding the determinants of oral microbiota communities might lead to better prevention and treatment strategies.
In this study, a team of researchers from the University of Colorado sequenced the microbial DNA present in the saliva samples of a cohort of twins, and matched the DNA sequences in a database to determine which types of bacteria were present in each individual. In their data set, they utilized samples that were gathered over a decade of adolescence from the same individuals to observe how the salivary microbiome changes with time.
By comparing the salivary microbiomes of identical twins, who share the same genetic make-up and live in a common environment, the group found that their salivary microbiomes were not significantly more similar than the salivary microbiota of fraternal twins, who share only half of their genes, suggesting genetic relatedness is not as important as environment. "The conclusion that genetic relatedness plays at most only a small role in microbial relatedness was really a surprise," said Dr. Ken Krauter, senior author of the study.
"We were also intrigued to see that the microbiota of twin pairs becomes less similar once they moved apart from each other," added Simone Stahringer, first author of the study, explaining further evidence for the influence of environment on oral microbiota. Interestingly, in the samples obtained from the same individuals over time, they found that the salivary microbiome changed the most during early adolescence, between the ages of 12 and 17. This suggests that factors such as puberty or prominent behavioral changes at this age might be important.
Krauter explained that their work uncovered another unexpected finding, that there is a core community of bacteria that are present in nearly all humans studied. "Though there are definitely differences among different people, there is a relatively high degree of sharing similar microbial species in all human mouths."
The authors suggested that this report has established a framework for future studies of the factors that influence oral microbial communities. "With broad knowledge of the organisms to expect to find in mouths," said Krauter, "we can now better understand how oral hygiene, environmental exposure to substances like alcohol, methamphetamines and even foods we eat affect the balance of microbes."
Stahringer SS, Clemente JC, Corley RP, Hewitt J, Knights D, Walters WA, Knight R, Krauter KS. Nurture trumps nature in a longitudinal survey of salivary bacterial communities in twins from early adolescence to early adulthood. Genome Res doi: 10.1101/gr.140608.112.
Cold Spring Harbor Laboratory: http://www.cshl.org
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
A veteran EMT and ambulance driver in Boston, Ed McCarthy is in a great position to understand his hometown spatially. But he’s also a history geek, and while constantly driving around the city’s neighborhoods, he loves recognizing the streets, buildings and other locales from the history books he so often buries his nose in.
The extinction of the biggest shark known to science may have triggered whales to grow to their current hefty sizes, a study suggests.
The UK's chief scientist says the oceans face a serious and growing risk from man-made carbon emissions.
Modifying neurons to flash as electrical impulses pass along them lets researchers grow light-up brains in a dish and eavesdrop on their chatter
They lived on a remote dot of land in the middle of the Pacific, 2,300 miles (3,700 km) west of South America and 1,100 miles (1,770 km) from the closest island, erecting huge stone figures that still stare enigmatically from the hillsides.
In a bleak, treeless landscape high in the southern Peruvian Andes, bands of intrepid Ice Age people hunkered down in rudimentary dwellings and withstood frigid weather, thin air and other hardships.
A viral video shows people lauding fare billed as an "organic" fast-food option that was actually McDonald's. It wasn't just pranksters playing tricks on these poor folks, but maybe their brains, too.
Deinocheirus mirificus, or unusual horrible hand, had long, clawed forearms, a sail on its back and a duck-like bill
Open letter says claims made for brain games are not based on sound evidence and that playing them may have opposite effect
A significant Bronze Age pottery find is made during an archaeological dig on the east side of Lewis, in Scotland.