The genes that enable lactose digestion are found mainly among white people. The Chinese use the name kefir cheese, because that is the name of the bacterium that ferments milk to form kefir. Amazingly there are still people who question the Europeanness of these people. In a previous study, scientists took tiny samples of 3,500-year-old cheese that adorned the necks of mummies. Protein analysis of the fragments revealed the presence of Lactobacillus kefiranofaciens, a microorganism used to make a fermented cheese called kefir. It was "really amazing," says Qiaomei Fu, a paleogeneticist at the Chinese Academy of Sciences in Beijing. Having had experience with ancient human DNA, she wanted to study the DNA of the fermenting microorganism.