Yeast Found in Gut Turned Into Very Good Sourdough

Even after his death in the Alps, a famous frozen mummy is still helping scientists make new discoveries − and even bake fresh bread. 

Researchers studying Ötzi the Iceman have identified living, cold-adapted yeast inside and around his preserved body and used one strain to bake sourdough bread, according to a study published June 03, 2026 in the journal Microbiome. 

The findings offer a rare glimpse into ancient human life and the microscopic organisms that have survived alongside the mummy for thousands of years. Scientists say the research also raises new questions about how best to preserve one of the world's most famous archaeological discoveries. 

"Our study reveals that Ötzi is not a static, biologically inert relic", lead author Mohamed Sarhan (right) of Italy's Eurac Research Institute told Reuters. "He is a dynamic ecosystem". 

Ötzi died roughly 5,300 years ago in the Alps near what is now the border of Italy and Austria. Research found he was probably killed by an arrow and was left preserved in glacial ice until hikers discovered his body in 1991. 

Today, the mummy is kept at minus 6 degrees Celsius (21 degrees Fahrenheit) in a special chamber at the South Tyrol Museum of Archaeology in Italy. The conditions closely match the icy environment that naturally preserved his remains for millennia. 

Scientists analyzed samples from Ötzi's skin, tissues and water collected from inside the mummy, according to Scientific American. They found evidence of ancient gut bacteria that helped digest food during his lifetime, along with yeasts that appear to have colonized the body shortly after his death. 

The study found several types of bacteria linked to high-fiber, pre-industrial diets. Some of these microbes still exist in modern humans, while others have become extremely rare, Reuters reported. 

Researchers said the findings support earlier studies showing Ötzi's diet included wild meat and cereals. According to Sarhan, some of the gut microbes found in the mummy are now seen mostly in non-industrialized populations, offering a snapshot of what the human microbiome looked like before processed foods, antibiotics and modern living changed it. 

The researchers were particularly surprised to find living, cold-adapted yeast. After reproducing the yeast in laboratory conditions, they used it to make sourdough bread. Sarhan told AFP that after several months of experimentation, the result was a "very, very good sourdough". 

The discovery may have implications beyond baking. Scientists found that some yeast species capable of breaking down phenol, a chemical used to disinfect the mummy after its discovery, have increased over time despite the freezing temperatures. Researchers say the finding could help improve preservation efforts for Ötzi and other frozen remains. 

"The main motivation of this study was the microbiological conservation of the mummy", Sarhan told Scientific American. "We wanted to understand whether the current conditions of the preservation are good enough". 

For now, the research suggests Ötzi remains more than a window into the distant past. Even after five millennia, scientists say, his body continues to reveal new secrets.