Generally, human feces do not tend to last for thousands of years, except in a few specific places such as dry caves, desert areas, waterlogged environments, and frozen habitats.
But by studying the ancient poo – the paleofeces – found in prehistoric salt mines in the UNESCO World Heritage area of Hallstatt-Dachstein in western Austria, the team uncovered “surprising evidence “: the presence of two fungal species used in the production of blue cheese and beer in historical samples. The high salt concentrations and the constant annual temperature of around 8 degrees Celsius inside the mine preserved the samples well, and the researchers say their results show the first molecular evidence for blue cheese and beer consumption. in the Iron Age in Europe.
“We were able to show that fermented foods have an important role in human history over a long period,” study author Kerstin Kowarik, archaeologist at the Natural History Museum in Vienna, told CNN. .
“The culinary practices were sophisticated, relying on complex food processing techniques such as fermentation and most likely aimed not only at preserving food, but also obtaining a specific taste,” she said. added.
“Through our study, we have also added to the long history of cheese and dairy products, by demonstrating that blue cheese was already produced in Iron Age Europe nearly 2,700 years ago”, she declared.
The researchers used in-depth scans to explore the microbes, DNA and proteins present in these poo samples, and reconstructed the diets of people who once lived in the area.
Bran was one of the most prevalent plant fragments in the samples, along with plant material from different grains. This very fibrous, carbohydrate-rich diet was supplemented with protein from beans and fruits, nuts, or animal foods, the researchers said.
When the researchers extended their microbial investigation to fungi, that’s when they got their biggest surprise: an abundance of DNA from Penicillium roqueforti and Saccharomyces cerevisiae – fungi found in cheese, beer and bread, respectively – in one of their Iron Age samples. .
“The Iron Age salt miners in the Hallstatt Salt Mountain appear to have intentionally applied food fermentation technologies with microorganisms that are still used in the food industry today, 2,700 ago. years, ”Kowarik added.
Author Frank Maixner, microbiologist and coordinator of the Eurac Institute for Mummy Studies in Bolzano, Italy, told CNN that the genomes of the fungi found in the samples “appear to have already undergone a screening process that makes food suitable for fermentation “.
“Therefore,” he added, “we assume that this fungus was part of an early fermentation culture.”
Experts say the ancient miners, who had a diet rich in plants, had gut microbiome structures similar to modern non-Westernized people, who mainly ate fresh fruits, vegetables and unprocessed foods.
In their findings, published Wednesday in the journal Cell Press, the team says their research suggests a more recent shift in the Western gut microbiome as eating habits and lifestyles have changed.