Studies on the preservation of the intestinal microbiota's DNA in human mummies from cold environments.

Analysis of ancient microorganism DNA represents one of the newest and most promising branches of molecular archaeology. In particular, microbial DNA associated with human remains can provide direct evidence of the occurrence and frequency of infectious diseases in historic times. Human mummies represent very interesting subjects for palaeomicrobiological investigations as they retain soft tissues. Recently reports on the identification of ancient bacterial pathogens in human mummies by DNA analysis are steadily becoming more numerous. However, despite this favourable trend, the analysis of ancient microbial DNA is still a contentious issue. As a model system, we studied the preservation of the intestinal microbiota's DNA in two naturally freeze-dried human mummies found on the Alps. This kind of mummy is an ideal subject for ancient DNA investigations. The first is a male body historically dated 1918 A.D. while the second is the famous Tyrolean Iceman (3.350-3.100 BC).