More than 5,000 years after his death, Ötzi the Iceman continues to provide scientists with valuable insights into prehistoric human life. A new study has now revealed unprecedented details about the microbial communities associated with the famous mummy, offering a deeper understanding of both his biology and the environment that preserved him.
Discovered by hikers in 1991 in a glacial region of the Tyrolean Alps, Ötzi is regarded as the oldest and best preserved naturally mummified human ever found. Researchers led by the Italian scientific institution Eurac Research employed advanced genetic analysis techniques to investigate the microorganisms linked to his remains.
The team examined ice collected from the mummy’s surface, meltwater obtained from its interior, and numerous swab samples. They also incorporated data from previous studies involving intestinal tissue and stomach contents, while analysing soil samples recovered from the original discovery site to assess potential environmental influences.
By combining multiple sources of evidence, scientists were able to distinguish between microorganisms that were part of Ötzi’s body during his lifetime and those that colonised the mummy after death, either during its millennia within the glacier or throughout more than three decades of modern preservation.
One of the study’s key findings was the confirmation of Ötzi’s original gut microbiome. Researchers identified genetic traces of bacterial communities that closely resemble those found in some of the earliest known human populations. Such microorganisms are now rarely present in the digestive systems of people living in industrialised societies, making Ötzi an exceptional window into humanity’s microbial past.
Another striking discovery was the presence of cold adapted yeast species capable of surviving in extremely low temperatures. These microorganisms were detected in skin samples, meltwater from within the mummy, and stomach contents. Genetic analyses linked them to strains currently found in some of the coldest environments on Earth, including Antarctica.
Scientists identified both heavily degraded ancient DNA and well preserved modern DNA from these fungi, suggesting that the organisms have not merely survived as biological remnants but may still persist in a dormant state under the mummy’s current storage conditions of approximately minus six degrees Celsius and high humidity.
According to Frank Maixner, director of the Institute for Mummy Studies at Eurac Research, the findings demonstrate that the mummy should not be viewed as a static archaeological object but rather as a dynamic biological ecosystem that continues to host microbial activity.
The study also suggests that historical conservation methods may have unintentionally influenced the microbial community. Several of the identified yeast species possess the genetic ability to break down phenol, a chemical once used to remove fungal growth from the mummy’s surface, potentially providing them with an unexpected nutrient source.
Beyond their archaeological significance, these cold-tolerant microorganisms could hold promise for industrial and biotechnological applications. Their ability to function efficiently at low temperatures may support the development of energy-saving processes, including cold-environment fermentation technologies.