Several thousand years ago, an Iron Age salt miner took a dump in what is now the Hallstatt-Dachstein/Salzkammergut area of Austria. In all likelihood, the pooper never gave their little deposit a second thought, and would be rather surprised to learn that it has now become a scientific artifact, enabling researchers to discover that Europeans ate blue cheese and drank beer 2,700 years ago.
Reporting the ancient excrement in the journal Current Biology, the study authors reveal that the paleofeces has remained preserved in the region’s prehistoric salt mines over the past few millennia. Using a range of analytical techniques, they were able to identify the microbes, proteins and DNA present in the poop samples. This, in turn, allowed them to build a picture of the diet of Iron Age miners in this part of Europe, as well as the composition of their gut bacteria.
Their findings revealed a diet rich in carbohydrates and high in fiber, consisting of largely unprocessed bran and glumes of various cereals, which were most likely consumed “in a sort of gruel or porridge.” This staple was supplemented with proteins obtained from broad beans, as well as fruits, nuts, and animal products.
The study authors also noted that the ancient miners’ gut microbiome strongly resembled that of modern non-Western people, whose diet generally consists of fresh fruits, vegetables, and other minimally processed foods. By comparing these ancient fecal samples to those produced by more recent humans, the study authors suggest that “the modern industrialized human gut microbiome has diverged from an ancestral state, probably due to modern lifestyle, diet, or medical advances.”
However, the most striking findings emerged when the researchers extended their analysis to include fungi, and detected high concentrations of species such as Penicillium roqueforti and Saccharomyces cerevisiae, which are used in the production of blue cheese and beer respectively.
“Genome-wide analysis indicates that both fungi were involved in food fermentation and provide the first molecular evidence for blue cheese and beer consumption during Iron Age Europe,” explained study author Frank Maixner in a statement.
According to the researchers, the Iron Age miners probably employed a method of beer fermentation that would have yielded a final product resembling what is nowadays known as a pale ale. The use of fungi to ripen cheese, meanwhile, would have enabled the miners to prolong the shelf life of milk while also removing much of the lactose, thereby making it easier to digest by a population with high rates of lactose intolerance.
While the production of fermented alcoholic beverages is considered to have been widespread in pre-history, the authors say that their findings represent “the earliest known evidence for directed cheese ripening and affinage in Europe, adding a crucial aspect to an emerging picture of highly sophisticated culinary traditions in European protohistory.”