The analysis of the oral DNA virome reveals which viruses are widespread and rare among healthy young adults in Valencia (Spain)

We have analysed oral wash samples from 72 healthy young adults in Valencia (Spain) for a metagenomic analysis through the construction of shotgun libraries and high-throughput-sequencing. The oral viral communities have been taxonomically characterised as well as and the gene content from the latter. The majority of viruses are found in few individuals, with single occurrences being the most widespread ones, whereas universally distributed viruses, while present, are relatively rare, with bacteriophages from families Siphoviridae and Myoviridae, and Streptococcus phages, as well as the eukaryotic viral family Herpesviridae amongst the most widespread viruses. No significant differences were found between females and males for either viruses and bacteria in abundance and alpha and beta diversity. The virome show similarities with other oral viromes previously reported for healthy individuals, suggesting the existence of a universal core of oral viruses, at least in the Western society, regardless of the geographical location.