Figure 4.

Diagram of the gut and bacterial and phage concentrations in the lumen, mucosa and epithelial cells. In the human gut, multiple different host-prey dynamics are theorised to occur dependent on the proximity to the gut mucosa. At the top of the mucosa, viruses take a lysogenic strategy or “piggyback-the-winner” as hosts are abundant here. Deeper within the mucosa, the viruses switch to a lytic or “kill-the-winner” strategy as at this point the bacteria are less abundant (Silveira and Rohwer, 2016). (Right) Some phages encode Ig-like domains that allow them to bind to the mucosa and evade the immune system, (Left) Phages can undergo transcytosis and be engulfed and transported through epithelial cells.