Scientists successfully extracted and sequenced DNA from a 3,600-year-old cheese found smeared on mummies in the Xiaohe cemetery in Xinjiang, Western China. The cheese, discovered nearly two decades ago, is now confirmed to be the oldest known cheese sample ever found.
A study published in the journal Cell details the DNA analysis of cheese found around a mummy’s neck, confirming it as kefir cheese made from goat and cow milk, according to El Periódico.
“We’ve gained a clearer picture of ancient human life and their interactions with the world,” Professor Qiaomei Fu said, as reported by The Sun. Fu is the director of the Ancient DNA Laboratory at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing.
The cheese was found around the necks and heads of several mummies in the Xiaohe cemetery.
The substance has been identified as kefir cheese, a fermented food containing species of bacteria and yeast that contribute to its fermentation, Gizmodo stated. Bacteria played a fundamental role in the kefir fermentation process, with high levels of Lactobacillus kefiranofaciens indicating its importance in fermentation practices, Science Alert reported.
Analysis of bacterial specimens in the cheese enabled researchers to track the evolution of Lactobacillus species crucial to fermentation, particularly L. kefiranofaciens. The study revealed that Lactobacillus kefiranofaciens exchanged genetic material with related strains, improving its genetic stability and milk fermentation capabilities over time.
Cheese production, including the making of kefir cheese, significantly reduces lactose content and prolongs the shelf life of raw milk, making dairy more accessible to lactose-intolerant individuals, La República stated.
The Xiaohe people consumed dairy before the era of pasteurization and refrigeration, despite being genetically lactose intolerant, Sky News reported. They likely developed fermenting processes that allowed them to incorporate dairy products, like kefir cheese, into their diet.
The research challenges the belief that kefir originated solely in the Caucasus Mountains, indicating two geographic origins: one in Xinjiang, where it has existed since the Bronze Age, and another in the Caucasus.
“These incredible findings show us that cheese and other dairy products were truly the foundation of an entire way of life that would remain important for millennia and continues to be an important part of life today,” William Taylor, Assistant Professor of Anthropology at the University of Colorado Boulder, stated, according to CNN.
Compared with ancient Lactobacillus, modern-day bacteria are less likely to trigger an immune response in the human intestine, La República noted.
The article was written with the assistance of a news analysis system.
This article was originally published at www.jpost.com
