Ancient DNA Reveals Secrets of 3,600-Year-Old Cheese Found in Western China

Recent discoveries in northwest China have shed light on a remarkable aspect of the Bronze Age, revealing that individuals buried in the region were accompanied by cheese strategically placed on their heads and necks, likely intended as sustenance for the afterlife. This intriguing find, unearthed from remarkably well-preserved mummified remains, has sparked scientific inquiry into the production and cultural significance of cheese in ancient times. Researchers have successfully extracted and sequenced DNA from the 3,600-year-old cheese, making it the oldest of its kind in the archaeological record. The groundbreaking analysis not only sheds light on the methods employed by the Xiaohe people in cheese-making but also underscores the profound impact of microbes on food production throughout history.

Published in the esteemed journal Cell, the findings open new avenues for ancient DNA studies, as noted by Christina Warinner, Associate Professor of the Social Sciences and Anthropology at Harvard University. Emphasizing the groundbreaking nature of this research, Warinner pointed out that it represents a paradigm shift in our understanding of ancient food production methods. The study of fermented foods has predominantly revolved around a limited number of commercial strains of bacteria and yeasts, neglecting the diverse range of heirloom microbes that shaped iconic foods in the past, from bread to cheese and beyond.

Unraveling the Past: The Discovery of the Xiaohe People
 

To delve deeper into the intricacies of ancient cheese-making, a team led by Chinese paleogeneticist Qiaomei Fu embarked on a quest to investigate the DNA of the cheese unearthed from the renowned Xiaohe cemetery in the Tarim Basin. This desolate region, characterized by its harsh environmental conditions, witnessed the discovery of hundreds of mummified individuals with facial features and hair color remarkably preserved despite their antiquity, dating back up to 4,000 years. The meticulous excavation revealed not only the remains of individuals but also their cultural heritage, encapsulated in unusual boat graves adorned with felted and woven clothing, captivating archaeologists for decades. The newfound insights challenge preconceived notions about the genetic isolation of the Xiaohe people, suggesting their receptiveness to adopting innovative ideas and technologies.

Notably, the research unveiled that the Xiaohe people employed a distinct approach to cheese-making, refraining from mixing different types of animal milk, a practice commonly observed in traditional Middle Eastern and Greek cheesemaking. Instead, they crafted cheese using previously made kefir grains, akin to modern practices, thereby emphasizing the continuity of knowledge transmission across generations and social networks.

Deciphering the Microbial Landscape: A Window into Evolution
 

The remarkable analysis conducted by Fu's team unveiled the presence of specific bacterial and fungal species in the ancient cheese samples, closely aligned with those found in contemporary kefir grains. This revelation not only underscores the enduring nature of microbial communities in food production but also provides a unique lens through which to observe the evolution of probiotic bacteria over the past 3,600 years. The comparative analysis between ancient and modern Lactobacillus species challenges established paradigms about the origins of kefir, opening avenues for further exploration into the historical trajectory of fermentation practices.

Illuminating the Past: Insights into Early Dairy Production
 

While the discovery of the ancient cheese is undoubtedly significant, it also prompts a reevaluation of the timeline of cheesemaking. Warinner affirms that the fermentation of milk to produce cheese is a practice that likely predates the Xiaohe civilization, suggesting its integral role in human subsistence for millennia. The insights garnered from this research not only enrich our understanding of culinary traditions but also underscore the profound interconnections between food production, culture, and societal advancement throughout history.