Sterile, bacteria-free mice with damaged guts can have their insides healed by a common rodent virus, providing the first evidence of internal, beneficial, virus communities.
Let me introduce a new word to your vocabulary: virome. The word’s made up of ‘vir’ from virus, and ‘ome’ as in genome – all of the genes in a creature.
You have your very own virome. Chances are that you have at least one virus in you right now, at least, and all of the dozens of genes in these viruses make up your virome.
The viruses you are harbouring might be disease-causing, they might be benign, or they might just be ‘passing though’, so to speak.
A previous study showed that an individual’s diet can affect their virome, but otherwise, we don’t know how stable our viromes are.
Of course, we are interested in studying disease-causing viruses, but of the benign viruses, we still know relatively little.
Microbiologists at the Langone Medical Centre at New York University have potentially found the first evidence of a virome promoting health in a mammal: not humans, but mice.
In both mice and humans, bacteria (not viruses) also live in guts and are known to be important for digestion and regular health.
For the study, the team fed antibiotics to mice, completely wiping out their gut bacteria, forming a blank slate. The researchers then fed a chemical to the mice, which damaged the tissues in their gut.
Half of the mice were then treated with a common rodent virus, Murine norovirus or MNV, while the others were not.
The mice treated with MNV lived longer, had healthier intestines, and less gut damage than mice free from the virus. The virally infected mice also showed better water retention during diarrhoea than uninfected mice.
MNV, like other viruses, has markers on its surface, which informed the mice’s immune systems of its presence. The immune system then gets activated by the virus, which then helps to restore the damaged gut.
Future studies will make moves to catalogue the variety of virus species in our bodies – the nasty ones, the passive ones, and the ones that can be either, under the right conditions.
And since a bulk of virus species infect bacteria, future studies will also have to figure out how our internal viruses interact with our all-important gut bacteria.
Research into the viral community of our guts is in its infancy, and if this field of study begins to blossom like the research into gut bacteria, it may well be a good idea to remember that new term: virome.
First published on Think Inc.
Feature photograph: Tom Thai/Flickr
Story source: Science Daily/