COVENTRY, ENGLAND—Microbial genomist Mark Pallen of Warwick Medical School and his colleagues used “shotgun metagenomics” to sample all of the DNA present in the bony nodules on a 700-year-old skeleton unearthed in Sardinia. They thought that the man had suffered from tuberculosis, but the results showed the DNA signature of Brucella melitensis, a microbe caught from working with livestock or consuming contaminated milk or cheese. The disease, known as brucellosis, causes chronic fatigue and recurring fevers, and has been diagnosed in other ancient skeletons, including a possible case in the human ancestor Australopithecus africanus. Pallen’s team is now using “shotgun metagenomics” to test other historic tissue samples. “We’re cranking through all of these samples, and we’re hopeful that we’re going to find new things,” he told Live Science.