The gut mobile metagenome comprises mobile genetic element (MGE) like bacterial viruses, known as bacteriophages. Although few studies showed that there is high interpersonal variation, little is known about how the gut microbiota react under phage attacks itselfs.
Reyes and colleagues used gnobiotic mouse to improve the understanding of viral-bacterial dynamics. They built an artificial microbiota using 15 bacterial sequenced strains and submitted them to original virus like particules extracted from human microbiota in mice.
Using deep shotgun sequencing, they found that some bacteria from their articfial microbiota became resistant to phage attack without genomic mutation. They hypothesized that this resistance came from an ecological resistant rather that genetic mutation.
Changes in community structure observed after attack were transient. Furthermore, a specific prophage induction confers to a bacterial strain an advantage to resist under fecal phages attacks from teh community and permit to maintain a relative high abundance.
Although this study make a lot of assumption using mice models and artificial community, there is no doubt that phage dynamics is an important factor to shape the struture and the dynamics of human gut microbiota. Furthermore, this study could be the first step for discovering phages as potential therapeutic agents.