The world’s oldest known cheese found in China!

In a groundbreaking discovery, scientists have successfully extracted DNA from a 3,600-year-old cheese, making it the oldest known cheese sample ever found. This ancient cheese, identified as kefir, provides fresh insights into the history of kefir and the development of probiotic bacteria.

The cheese was initially found almost two decades ago in the Tarim Basin, China, when archaeologists unearthed hundreds of mummies. Unusually, a white substance had been smeared across the heads and necks of several mummies. At the time, researchers were unable to determine what this substance was, but recent advances in DNA analysis have allowed a team, led by Qiaomei Fu from the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences, to confirm its identity as kefir cheese.

Photo Credit: Y, Liu et al., Cell.

Fu explained, "This is the oldest known cheese sample ever discovered in the world." The preservation of food like cheese over thousands of years is extremely rare, making this an invaluable find. According to Fu, studying these ancient remains offers important clues about the diet and cultural practices of our ancestors.

DNA extracted from the cheese revealed that the ancient people of Xiaohe used cow and goat milk separately to make their cheese, a process different from the mixed milk traditions found in regions such as Greece and the Middle East. Further genetic analysis uncovered bacterial and yeast species, including Lactobacillus kefiranofaciens and Pichia kudriavzevii, which are common in modern kefir grains used for fermenting milk into kefir cheese—similar to the process used for sourdough bread.

One of the most surprising findings was that the ancient Lactobacillus kefiranofaciens strain found in the cheese closely resembled a strain still present in Tibet today. This challenges the belief that kefir only originated in the Caucasus Mountains of Russia. Fu's research suggests that kefir culture may have been maintained in northwestern China since the Bronze Age.

Photo Credit: Y, Liu et al., Cell.

Interestingly, the ancient cheese had higher levels of Lactobacillus kefiranofaciens than modern kefir, which likely made it more reactive to the human immune system. Over the past 3,600 years, the bacteria have evolved alongside humans, becoming less likely to trigger immune responses. Fu described the study as "unprecedented," allowing scientists to observe how bacteria have evolved over millennia. These genetic adaptations have improved the bacteria's ability to ferment milk, enhancing the stability of kefir production.

The discovery also raises intriguing questions about why the cheese was smeared on the mummies. While the exact reason remains unclear, one theory suggests that the cheese was a delicacy intended for the afterlife. The Xiaohe people might have believed that the rare cheese could nourish the spirits of the deceased or play a ceremonial role in their burial practices.

This extraordinary find not only deepens our understanding of ancient food preservation but also reshapes the history of kefir and probiotic bacteria, offering a rare glimpse into the diets and cultural beliefs of ancient civilisations.