A new study published in Cell Host & Microbe  of mice with a defined gut microbiota, led by scientific por Brigham and Women´s Hospital at Harvard Medical School (Massachusetts, USA), characterizes the impact of bacteriophages in gut bacterial populations at composition and metabolome levels.

The researchers administered 4 lytic phages to mice previously colonized with a defined set of 10 selected bacterial species, which include species from Firmicutes, Bacteroidetes, Proteobacteriaand Verrucomicrobia phyla that usually inhabit the human gut microbiome.

Murine fecal samples were collected for 44 days with the aim of longitudinally tracking and characterizing changes in gut bacterial populations before and after phage administration. Both phages and their targeted bacteria were detectable in stool samples throughout the experiment.

The authors also determined in vitro that, whereas a subsample of Enterococcus faecalis present in the mice gut microbiota was sensitive to phages, another population acquired resistance 2 and 10 days after phage administration. Just like gut bacteria may be involved in transferring antibiotic resistance genes, bacteria residing in the in the gut can also acquire resistance to phages.

Read more: Gut microbiota for health