Cheesy date pushed back
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Researchers have discovered the world’s oldest cheese.
Scientists in China have unearthed samples of cheese dating back approximately 3,600 years.
The cheese was found alongside mummies in the Tarim Basin in Northwestern China. This ancient find not only sheds light on Bronze Age food practices but also challenges long-held beliefs about the origins of kefir, a fermented dairy product.
The mummified remains were first uncovered about two decades ago in the Xiaohe cemetery, where archaeologists noted strange white substances smeared on the necks and heads of several mummies.
At the time, the exact nature of the substance remained a mystery.
Recent advances in DNA analysis, however, have allowed a team of researchers, led by Qiaomei Fu of the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences, to finally identify the substance as kefir cheese.
“This is the oldest known cheese sample ever discovered in the world,” Fu stated.
Scientists have noted the rarity of such preservation, as food items like cheese typically decompose over time.
The team successfully extracted and analysed mitochondrial DNA from the cheese samples, revealing the presence of cow and goat milk.
Furthermore, the researchers identified the DNA of Lactobacillus kefiranofaciens, a microorganism still used today in the production of kefir.
This discovery provides new insights into the cultural practices of the Xiaohe people, who were producing cheese from both cow and goat milk in separate batches - a practice distinct from other ancient cheese-making traditions, such as those in the Middle East and Greece.
The identification of Lactobacillus kefiranofaciens in the ancient cheese sample also suggests that kefir-making may have been an ongoing tradition in China since the Bronze Age.
The findings, published in Cell, also cast doubt on previous assumptions that kefir originated in Russia's Caucasus mountains.
Instead, the study suggests that kefir-making may have developed independently in China, with the microbial strains used by the Xiaohe people most closely related to modern strains found in Tibet.
“Our observation suggests kefir culture has been maintained in Northwestern China’s Xinjiang region since the Bronze Age,” Fu said.
The genetic analysis of the ancient microorganisms has also provided valuable information about the evolution of probiotic bacteria.
Compared to ancient strains, modern Lactobacillus species have become less likely to provoke immune responses in humans, indicating thousands of years of adaptation to human hosts.
These insights not only enrich the understanding of ancient diets but also underscore the role of human activities in shaping microbial evolution.
“This is an unprecedented study, allowing us to observe how a bacterium evolved over the past 3,000 years. Moreover, by examining dairy products, we’ve gained a clearer picture of ancient human life and their interactions with the world,” Fu said.
The discovery adds a new chapter to the history of kefir, demonstrating its deep roots in Central Asia and suggesting cultural exchanges between the Xiaohe population and neighbouring regions.
The team hopes this research will pave the way for further exploration into ancient human diets and microbial interactions.