In the past years our current understanding of the role of phages in nature and their potential in medicine has shifted from mere “viruses of bacteria” that influence the number and functions of bacteria and could be used to combat bacterial infections to the notion of an important component of our organisms abundantly present in the intestines, from where phages can migrate to blood and tissues. Thus, it is becoming evident that phages can interact not only with bacteria but also with eukaryotic cells.
Research on the significance of such phage-eukaryotic cell interactions is at a very early stage. However, data obtained so far strongly suggest that phages may induce immunomodulatory effects which can be used in the clinic in PT.
Moreover, these novel findings highlight the potential protective role of “endogenous” phages present in the human body (“natural PT”). In this sense, a better understanding of mechanisms responsible for prophage induction in vivo and the significance of such phages may yield new and exciting data, including the possible role of HP in regulating this process in health and disease.