The human oral phageome is highly diverse and rich in jumbo phages

Until recently, the contribution of bacteriophages to the composition and function of the human microbiome has been largely overlooked. Recent developments in discovering novel bacteriophages from human metagenomes have been mostly focused on the gut. Here we profile and compare the phageome of 633 human oral sites and 221 paired gut phageomes acquired from countries worldwide. Phageome profiles are specific to oral sites and the gut across individuals, with the largest separation between the oral cavity and the gut. The differences in phage genotypes is bolstered by distinct phage host compositions between these sites. The greatest diversity of phages is found on the tongue and in dental plaque. Notably, 37 unique circular jumbo phage genomes were identified in oral sites, particularly on the dorsum of the tongue, whilst none were found in the gut. Oral sites provide conducive environments, such as robust biofilms, that can harbour genetically diverse phages.