The 5,300-year-old Ötzi the Iceman has long fascinated researchers, offering a glimpse into the life of a hunter frozen in the Alps in 1991. A team of scientists has now made a groundbreaking discovery, using yeast from Ötzi's gut to create sourdough bread.
Researchers examined colonies of yeast taken from Ötzi's stomach, uncovering new insights into the complex microbial ecosystem surrounding the mummy. They separated microorganisms from his lifetime from those that colonized his remains after death, both in the ice and during modern preservation. The team found continuity in the yeast, which has accompanied Ötzi on his long journey through the millennia.
The study demonstrates that Ötzi is not a static relic, but a dynamic biological system. Scientists reproduced one of the strains of yeast found in Ötzi's gut, keeping it alive for three months before producing sourdough bread. This unusual experiment highlighted the potential applications of the microorganisms, which could be used in low-temperature fermentation processes.
The investigation involved an extensive analysis of Ötzi and his surroundings, including ice from the surface of the body, meltwater, and swab samples. The team supplemented this with data from previous studies of intestinal tissue and stomach contents. A soil sample collected from the site where Ötzi was discovered was also examined to help trace environmental influences.
The presence of genetic material from Ötzi's original gut microbiome in both the intestinal tract and stomach contents was a significant finding. This ancient microbiome closely resembles the limited number of known gut microbial communities from early human populations, offering a rare glimpse into humanity's microbial past.
The newly identified yeasts were isolated from skin samples, meltwater from inside the mummy, and stomach-content samples. These highly specialized organisms are adapted to survive in extremely cold conditions, showing similarities with strains found in some of the coldest places on Earth, including Antarctica.
The study expands our knowledge of the preservation conditions for glacial mummies, highlighting the need for further research and conservation efforts. The findings were published in the journal Microbiome, offering new insights into the complex microbial ecosystem surrounding Ötzi the Iceman.
