London: Oetzi the Iceman, Europe`s oldest known natural mummy of a man who lived around 3,300 BCE, indeed suffered from periodontitis, examination of its non-human DNA confirmed.
This finding supports the computer tomography based diagnosis that the Iceman suffered from periodontitis, a set of inflammatory diseases affecting the tissues that surround and support the teeth.
Much of what we know about Oetzi - for example what he looked like or that he suffered from lactose intolerance - stems from a tiny bone sample which allowed the decoding of his genetic make-up.
Now, however, a team of scientists has examined more closely the part of the sample consisting of non-human DNA.
"This `non-human` DNA mostly derives from bacteria normally living on and within our body," said Thomas Rattei, professor of bioinformatics at University of Vienna in Austria.
Only the interplay between certain bacteria or an imbalance within this bacterial community might cause certain diseases. Therefore, it is highly important to reconstruct and understand the bacterial community composition by analysing this DNA mixture, Rattei noted.
The researchers detected in the DNA mixture a sizeable presence of a particular bacterium - Treponema denticola, an opportunistic pathogen involved in the development of periodontitis.
What is surprising is that the analysis of a tiny bone sample can still, after 5,300 years, provide the information that this opportunistic pathogen seems to have been distributed via the bloodstream from the mouth to the hip bone.
The bacteria did not colonise the body after death, the scientists indicated.
The findings appeared in the journal PLOS ONE.