Characterizing phage-host interactions in a simplified human intestinal barrier model

An intestinal epithelium model able to produce mucus was developed to provide an environment suitable for testing the therapeutic activity of gut bacteriophages. We show that Enterococcus faecalis adheres more effectively in the presence of mucus, can invade the intestinal epithelia and is able to translocate after damaging tight junctions. Furthermore, Enterococcus phage vB_EfaM_A2 (a member of Herelleviridae that possesses virion associated immunoglobin domains) was found to translocate through the epithelium in the presence and absence of its host bacteria. Phage A2 protected eukaryotic cells by reducing mortality and maintaining the structure of the cell layer structure. We suggest the mammalian cell model utilized within this study as an adaptable in vitro model that can be employed to enable a better understanding of phage–bacteria interactions and the protective impact of phage therapy relating to the intestinal epithelium.