The oral microbiome and its impact on teeth has changed from the paleo era to the more recent agrarian one with its industrial revolution. That change has not been beneficial for our teeth.
At the Biomedx live hands-on workshops, you might know we use the lab microscopes not just for various live blood and dry layer perspectives, but for gingival scans as well.
The well defined spirochetes that are often found there definitely get people’s attention.
As I was assembling material for the Dental Microscopy module at edu.biomedx.com, a tidbit on plaque popped up which I thought might be of interest to you…
A team of researchers led by Alan Cooper of the Australian Centre for Ancient DNA at the University of Adelaide, decided to delve into ancient biofilms of the mouth – as well as more recent ones – to see what they could tell us about the evolution of the human diet and its impact on our oral ecology and health.
The researchers collected calculus samples from 34 human skeletons dating from between 400 (late medieval) and 7,500 years ago (mesolithic), as well as from 10 members of the research team for a modern comparison. They extracted and amplified specific diagnostic segments of microbial DNA from the 16S ribosomal RNA gene, and then sequenced what they found.
The result gave them a bacterial census indicating roughly the numbers and identities of the different kinds of bacteria present. (There’s actually a database of these sequences online; the Human Oral Microbiome Database lists some 600+ bacterial 16S ribosomal RNAs, and counting.)
When they plotted those sequences, the researchers could see a clear change in the nature of our oral microbiomes over the past eight millennia. The first change occurred as human society transitioned from hunting and gathering to farming, a change associated with an increase in grain consumption in our diet.
“The composition of oral microbiota underwent a distinct shift with the introduction of farming in the early Neolithic period, with the earlier hunter-gatherer groups having fewer caries and periodontal disease-associated taxa,” they wrote.
Following that shift, oral microbial communities remained mostly stable until relatively sometime after the medieval period, when overall bacterial diversity in the mouth declined and the prevalence of pathogenic bacteria (those associated with dental disease) rose.
In particular, “modern” mouths have much higher levels of Streptococcus mutans and Porphyromonas gingivalis, two known oral pathogens, a change the authors attribute to the Industrial Revolution.
“The Industrial Revolution saw the production of refined grain and concentrated sugar from processed sugar beet and cane, generating mono- and disaccharides, which are the main substrates for the microbial fermentation that lowers plaque pH and causes enamel demineralization.”
Overall, the authors write, the human mouth has become “a substantially less biodiverse ecosystem” over the past few hundred years.
“In both human-associated microbiota and macroecological contexts, higher phylogenetic diversity is associated with greater ecosystem resilience and productivity. Therefore, the modern oral environment is likely to be less resilient to perturbations in the form of dietary imbalances or invasion by pathogenic bacterial species.”
“What you’ve really created is an ecosystem which is very low in diversity and full of opportunistic pathogens that have jumped in to utilize the resources which are now free.”
As the research infers, where this leaves us today is with oral microbiotic ecosytems that are markedly less diverse than historic populations. And I would guess as Westin Price might have suggested, we need to cut down the carbs and eat more like our ancestors.
Is that some positive commotion I hear from the paleo side of the aisle?
Oh, maybe it’s just grumbling from the overly carbed vegetarian and vegan side.
Either way, I think it’s time to have some steak.
Oh wait, dang, I’m blood type A.
I guess it’s a veggy burger then…
Naaahh, I’m thinking about my teeth.
Please pass those enzymes and HCL…