Researchers from the Australian Centre for Ancient DNA in the University of Adelaide have discovered a change in the bacteria responsible for tooth decay. The change occurred as our diet changed over the centuries. Compared to our mouths now, Mesolithic hunters and gathers had healthier mouths with almost no oral health problems such as cavities and gum disease.
Researchers saw this difference by taking DNA from dental plaque belonging to thirty-four prehistoric Northern European skeletons. They noticed that there was a change in the composition of bacteria that causes tooth decay when farming was introduced and then again during the Industrial Revolution.
In prehistoric times, bacterial diversity was higher in people`s mouths, which meant they were more resilient to stresses and less likely to develop diseases. Bacteria associated with dental cavities like S. Mutans became more common around the Industrial Revolution. On the other hand, the amount of bacteria associated with periodontal diseases like gingivitis has not changed since farming began.
This is good news to those who have a diet that is high in meat and low in grains. Most of us eat more processed flour and sugar and both contribute to modern day oral health problems, which is an interesting comparison.
If you wish to learn more about this study, click here: http://www.abc.net.au/science/articles/2013/02/18/3691558.htm.