Q&A: Laura Weyrich

The associate professor of anthropology's study of ancient teeth could help modern dentistry.

dental illustration

Q: Most human microbiome research is focused on the gut but you study oral microbiomes—ancient ones, to boot.
: That’s right. Teeth have enamel, harder than bone in many cases, and they stick around for a long time. Dental plaque will actually harden in place into what we call calculus, or tartar. That’s a rock-hard matrix that survives through time, whereas the gut is made of soft tissue that decays over time. You can quite easily pop off the rock-hard calculus on teeth, dunk it in bleach to decontaminate it, then crack it open and see what’s inside.

Q: How do you do that?
: My team essentially performs Paleolithic dentistry. We scrape the teeth of past individuals, then we sequence the DNA inside and use that to reconstruct the types of microbes, bacteria, viruses, and fungi that lived in people’s mouths in the past.

Q: And what do you find?
: Well, Neanderthals, for instance, had amazing teeth. They had very few cavities, no periodontal disease. But through time and as we’ve gotten closer to today, we started getting really nasty bugs in our mouths. Most of our teeth would essentially rot and fall out of our mouths if we didn’t have dentistry, if we weren’t brushing our teeth twice a day. We’re trying to figure out that transition, describe how it occurred and is still occurring in some modern populations.

Q: Can your analysis of ancient teeth help to make our modern teeth better?
: Absolutely, our goal is to apply our findings to modern dentistry practice. I’m leading a grant in conjunction with the University of Adelaide in Australia that’s developing oral microbiome transplants. The idea is to develop a super healthy microbiome that we can use to treat disease. Perhaps one day we’ll develop a Neanderthal microbiome and transplant it into people’s mouths.

Q: How would you do that?
: We’re hoping to find collections of healthy bacteria that we know are in the mouths of really healthy people today, perhaps similar to microbes that we might find in Neanderthals or other really healthy ancient humans. We grow these microbes and then try to essentially paint them on people’s teeth. That’s basically transplanting a whole set of really good bacteria that could outcompete and push out the bad, modern bugs to hopefully create a healthy environment where you wouldn’t have to brush your teeth every day.


Laura Weyrich ’12 PhD Sci is an associate professor of anthropology and a principal investigator of paleomicrobiome research.