Mind Those Mouth Microbes

Colorado State University microbiome research published in Scientific Reports found a correlation between not visiting the dentist on a regular basis and an increased presence of the pathogen Treponema that causes periodontal disease in experiments carried out on a wide cross section of volunteers who submitted to a cheek swab as well as answering questions about their lifestyles, demographics and health habits. Microbial DNA sequencing data revealed that oral health habits affect the communities of bacteria in the mouth, underscoring the need to think about oral health as being strongly linked to the health of the entire body. 

"Our study also showed that crowdsourcing and using community scientists can be a really good way to get this type of data, without having to use large, case-controlled studies," said Zach Burcham, a postdoctoral researcher and the paper's lead author. Senior author Metcalf is an associate professor in the Department of Animal Sciences and a member of CSU's Microbiome Network.

Co-author Nicole Garneau trained volunteer scientists to use large swabs to collect cheek cells from a diverse population of 366 volunteers aged 8 and up who consented to determine whether and to what extent oral microbiome contributes to how people taste sweet things. CSU scientists used sequencing and analysis tools to determine which microbes were present in which mouths. 

"Together, we had a dream team for using community science to answer complicated questions about human health and nutrition, using state-of-the-art microbial sequencing and analysis," Garneau said.

Participants were grouped by those who flossed and those who didn’t floss, all reported brushing their teeth. Those who flossed were found to have lower microbial diversity which is likely due to physical removal of bacteria that can cause inflammation and disease. Adults that had seen a dentist in the past 3 months had overall lower microbial diversity as well as less of the pathogen (Treponema) that causes periodontal disease. Youths tended to have had more recent dental visits than adults. 

Oral microbiomes differed among youth males and females; and obese children had distinct microbiomes compared to those who were not obese based on BMI. Obese children tended to have higher levels of Treponema which is the same pathogen found in adults who hadn’t seen a dentist in over a year. The researchers think there may be a link between childhood obesity and periodontal disease. 

"This was very interesting to me, that we were able to detect these data in such a general population, with such a variable group of people," Burcham said.

Oral microbiomes in those that were younger had more diversity than adults, but adults varied more widely from person to person; and those who lived in the same household also shared similar oral microbiomes. 

"When you look at families who live together, you find they share more of those rare taxa, the bacteria that aren't found as often in higher abundances," Burcham explained. It was a data point that underscored the relevance of one's built environment in relation to the microbial communities in our bodies.

"I think how our lives are essentially driven by our microbiomes, and affected by our microbiomes, is interesting, no matter what system we're looking at," Burcham said.