Researchers discovered the world’s oldest cheese, a 3,600-year-old kefir cheese, on mummies in China’s Tarim Basin. DNA tests revealed it was made from cow and goat milk and contained bacterial and fungal species found in modern kefir grains. This discovery, published in Cell, offers insights into ancient diets and cultures. The cheese’s preservation is rare, and its study helps track the evolution of probiotic bacteria over millennia. The findings suggest kefir culture has been maintained in Northwestern China’s Xinjiang region since the Bronze Age.