Ancient Cheese DNA Reveals 3,600-Year-Old Kefir-Making Practices in China's Tarim Basin

Ancient cheese DNA reveals 3,600-year-old kefir from Xiaohe mummies, showing goat/cattle milk use and probiotic history.

Discovery of Ancient Cheese in the Tarim Basin

Archaeologists working in the Xiaohe cemetery within China's Xinjiang region uncovered remarkably preserved mummies and artifacts over a decade ago. Among the grave goods were fragments of cheese, which have now been confirmed as the oldest known cheese samples in existence. The naturally mummified remains date back up to 4,000 years and were accompanied by woven textiles, felted garments, and distinctive boat-shaped burial pits. Recent DNA extraction and sequencing from these cheese remnants have provided unprecedented insights into the dietary habits of the Xiaohe people, with results published in the journal Cell.

DNA Analysis Reveals Kefir Production

Genetic analysis of the cheese showed that it was produced from both goat and cattle milk. The microbial composition—including Lactobacillus kefiranofaciens and Pichia kudriavzevii—confirmed the cheese was a fermented kefir, a type still consumed in many cultures today. Interestingly, the study found no evidence of milk mixing; the Xiaohe people appear to have maintained separate batches for each animal type, differing from traditional Middle Eastern and Greek practices that often combine milks. This distinct technique sheds light on the unique culinary methods of this ancient desert society.

Cultural and Technological Insights

The Xiaohe cemetery mummies have long fascinated researchers due to the population's genetic isolation and the diverse cultural signals in their burial practices. The adoption of cheese-making technology suggests that despite their isolation, the Xiaohe people were receptive to new ideas and techniques. This discovery enriches our understanding of how they adapted to and interacted with their arid environment.

Evolution of Probiotic Bacteria Over Millennia

The ancient cheese DNA also provided a rare look at how probiotic bacteria have evolved over the past 3,600 years. The Lactobacillus kefiranofaciens strain from the Xiaohe cheese shows deep roots in the Tibetan Plateau, in contrast to the widely used Russian strain common in modern yogurt and cheese production. This finding highlights a long-standing tradition of microbial culture use in fermentation and offers a historical timeline for the spread of beneficial bacteria.

Implications for Ancient DNA Research and Modern Science

This successful sequencing opens new avenues for studying ancient foods and their microbial communities. By analyzing the microorganisms involved in early fermentation, scientists can reconstruct historical dietary practices and trace the development of food technologies. Moreover, the research underscores the power of ancient DNA studies to reveal complex cultural and biological interactions between humans and their environment. As similar studies expand, we can anticipate deeper knowledge of how fermented foods have shaped human health and cuisine throughout history.

For further reading, refer to the original study in Cell.