In 2012, an American collaboration of researchers took a closer look inside the mouth and found close to 100 million phages per milliliter of saliva. To suggest there was no biological function was no longer an option; the viruses were there and doing something. Unfortunately, there were still no hard answers to determine what those functions were. But last week, a Californian team of researchers including one of the authors from the 2012 study unveiled some of the mystery behind the contribution of the oral virome to health. The group looked at the saliva as well as the supra- and sub-gingival plaque of 16 volunteers. But in this study, half of them had periodontal disease. The hope was to identify a difference in the nature of the oral virome. The results provided more than they expected.