The human virome is a collection of all viruses, both eukaryotic and prokaryotic, present in and on the human body. It includes viruses that infect human cells, but also those that infect bacteria (bacteriophages) and other microorganisms that make up the human microbiome. Different body parts contain different viruses. Gut virome is the best explored and it is dominated by phages, especially Caudovirales and Microviridae. Virome is formed soon after birth and initially consists of bacteriophages, but, gradually during the early life of newborns, eukaryotic viruses begin to appear in its composition. The composition of the virome is influenced by numerous factors such as diet, geography, age, genetics, environment, etc. How the virome interacts with organism is not yet fully understood. It is known to cause infections and stimulate immune responses. It is also known that phages can prevent bacterial infections by lysis of bacteria, but also that they can transmit on bacteria some new properties, such as resistance to antibiotics. Significant virome studies has only recently begun and much research is still needed in this area.