In an extraordinary advancement, scientists have sequenced DNA from a 3,600-year-old cheese, marking it as the oldest cheese in the archaeological record.
This intact cheese, found alongside mummified remains in China, offers profound insights into ancient food production and microbial utilisation.
Discovery in the Tarim Basin
The astonishing discovery was made in the Xiaohe cemetery within the arid Tarim Basin of China’s Xinjiang region during the 1990s. Hundreds of well-preserved mummies were buried with cheese scattered around their heads and necks, potentially as provisions for the afterlife. These remains, with discernible facial features and hair, date back up to 4,000 years.
Scientists have recently extracted and sequenced DNA from this ancient cheese, revealing significant details about how the Xiaohe people produced and utilised dairy products. The findings have opened a new frontier in ancient DNA studies, showcasing technological advancements that were unthinkable a decade ago.
How the Xiaohe People Made Kefir
The research highlighted that the Xiaohe people made cheese similarly to modern kefir cheese production, without mixing different types of animal milk, a common practice in the Middle East and Greece. This method utilised previously made kefir grains, transferred through familial and social networks, akin to the use of kombucha mothers or bread starters.
These findings underscore that while the Xiaohe people were genetically isolated, they were willing to incorporate new ideas and technologies. This discovery gives us valuable insights into how microbial commodities were distributed and preserved across Asia.
Evolution of Probiotic Bacteria
Analysis of the cheese samples revealed the presence of bacterial and fungal species, including Lactobacillus kefiranofaciens, which are commonly found in modern kefir grains. Researchers sequenced bacterial genes within the ancient kefir cheese, offering a glimpse into the evolution of probiotic bacteria over 3,600 years.
Fu’s team found that the ancient kefir cheese contained a less common group of Lactobacillus bacteria that originated in Tibet. This challenges the belief that kefir originated exclusively in the Caucasus Mountains, suggesting a more complex geographical history of fermentation practices.
These results provide unprecedented insights into ancient human life and their interaction with the environment, revealing much about the evolutionary journey of these essential microbes.
Implications for Ancient and Modern Food Production
The cheese’s ability to survive over millennia and yield sequencable DNA is a testament to the durability of dairy products and their historical importance. This research gives us a deeper understanding of how ancient peoples harnessed and controlled fermentation, an essential skill for preserving food before modern refrigeration.
Ancient cheese-making processes likely formed the foundation of many food preservation techniques that are still in use today. Ensuring milk could be stored safely was crucial, necessitating microbial degradation through fermentation to make it digestible and to extend its shelf life.
Cheesemaking: An Age-old Tradition
Cheesemaking is an ancient practice that predates this discovery. Evidence such as animal proteins in human dental calculus and milk residues on pottery suggests its origins lie around 9,000 years ago in Anatolia or the Levant.
The genomic analysis performed in this study highlights the complexity of dairy production and its role in ancient societies. Over the millennia, people have become adept at selecting specific microbes to create desirable fermentation effects, enhancing food’s flavour, texture, and nutritional value.
These findings not only enhance our understanding of ancient cheesemaking practices but also illuminate the enduring importance of dairy products throughout human history.
Future Directions for Research
Further research is needed to expand on these groundbreaking discoveries, as they represent just the beginning of our understanding of ancient microbial utilisation and food production.
Continued exploration of ancient DNA could reveal more about how early humans interacted with their environment, offering a broader picture of human development and technological advancements.
The DNA sequencing of a 3,600-year-old cheese from China offers unprecedented insights into ancient dairy production and microbial evolution, opening new avenues for research.
This discovery not only sheds light on past human practices but also enhances our understanding of how crucial microbial interactions were for the survival and advancement of ancient societies.
