Researchers have reported that an analysis of the dental calculus, also called tartar, of ancient skeletons shows that the parasitic bacteria that cause cavities and gum disease in our mouths has been essentially unchanged for thousands of years.

Ancient Tartar Reveals “Microbial Pompeii”


Researchers began analyzing the tartar in ancient skeletons knowing that tartar preserves a great deal of evidence about the living animal and expected to find information about parasitic bacteria.

Tartar occurs when the plaque on your teeth becomes mineralized. The combination of hyaluronic acid protective gel and dead bacteria essentially become fossilized in your mouth because they take up some of the mineral ions in your saliva that also help repair the enamel of your teeth. This is why you can’t remove tartar yourself, but have to have it removed in a professional dental cleaning. Because they are already fossilized when you are buried, they can preserve and protect genetic information, unlike bones, which usually lose this information quickly.

However, they were unprepared for the amazing amount of information they discovered, as they were not only able to identify 40 different species of parasitic bacteria–all of which are still found in our mouths today–they were able to reconstruct the complete genome of one bacterium and found evidence of more than 300 human and bacterial proteins.

They were even able to identify plants in the human diet whose existence was otherwise unknown.

The finds were so complete that they compared it to a “microbial Pompeii,” preserved in calcified tissue rather than in falling ash.

Surprising Resistance?

One thing that they discovered about the genetic profile of the bacteria they discovered is that they seem to have in them the genetic basis of resistance to antibacterial medication at least 800 years before these antibacterial agents were identified and used therapeutically.

However, this shouldn’t be too surprising, because antibacterial agents are probably at least as old as bacteria themselves. Remember that our first antibiotics (such as penicillin) were derived from natural toxins produced by fungus in their ancient war against bacteria. Of course bacteria have been exposed to antibiotics over the millenia and have developed mechanisms to counteract and overcome them.

With this long history of parasitism, and with the obvious success of these parasitic bacteria, it does seem increasingly unlikely that we will ever fully eliminate these bacteria.