What the average person knows about viruses is pretty bad. We know they can only reproduce by invading a cell of a different species and usurping its normal function. We know that some of the worst disease ever are caused by viruses: Ebola, polio, AIDS, hepatitis, influenza, etc. So how could we ever think of a virus as beneficial? Dr. Marilyn Roossnick of Pennsylvania State University tells us that, just as we carry around a biome of beneficial bacteria, we also carry our own population of funguses and viruses that don’t make us sick.
Many of Roossnick’s examples focus on plants and insects as there is more information on the symbiosis in this realm than in the human environment. But she does point out several critical factors already known about viruses in the human body. We have a population of viruses in the gut, the skin, and even in the blood. This particular fact has been known for well over forty years. This viral collection even has its own name to counter the bacteria-centric focus of the microbiome; it’s called the virome.
The virome appears at a very young age and appears to be dynamic in the first months of life. But, eventually the population tends to settle. Each of us has a unique collection of viruses although there are some species common to us all.
There are three ways viruses can be beneficial: some attack invading bacteria instead of human cells, some compete with pathogenic viruses and keep them at bay, and some have even contributed to our DNA somewhere along our evolutionary line. Read about how this happens and how it benefits us at Popular Science. -via the Presurfer