Are there good viruses? - Big Questions - (Ep. 204) | Mental Floss

Hi, I'm Craig. I contracted the beauty virus, and this is Mental Floss on YouTube

Today, I'm going to answer Akali Baby 808's big question. Are there good viruses? Let's get started

It turns out that virus doesn't necessarily mean disease. In fact, there are actually trillions of viruses in our bodies, and they're not all bad

A virus just is a microorganism that can only reproduce if it's in a living organism

And often they're the cause of disease and disease spread, but some viruses might be good for us

For centuries, people have found ways for viruses to be advantageous. For instance, in the 1700s it was discovered that milkmaids who had a mild version of cowpox were immune to virulent smallpox

Because of this discovery, scientists were able to develop a smallpox vaccine with the vaccinia virus, which is related to the cowpox virus

It's possible that viruses might be crucial to the development of healthy organs. In 2011, immunologist Ken Cadwell conducted an experiment to learn more about the microbiome

a group of about 100 trillion microbes in our bodies. The microbiome has a lot of important roles, like aiding the development of intestines

And I love my intestines, both large and small. Dr Cadwell found that raising young mice in a completely sterile environment affected the microbiome so that their intestines didn develop normally But when he gave the mice a murine norovirus similar to the one that affects humans their intestines and immune system developed normally

That's the virus you get on a cruise ship, right? So did he give the mice, did he put the mice on a cruise ship

I don't want to be on that cruise ship. This study may apply to people, meaning exposure to viruses at a young age might be good for us

But Cadwell notes that viruses affect people differently, so it won't work the same way for everyone

There are also viruses known as phages, found in our body's mucus, like in the mouth, nose, digestive tract. Eww

And phages actually kill unwanted bacteria. A 2013 study in the Proceedings of the National Academy of Sciences, or PNAS, found that when

a phage was put with an E. coli bacterium in a culture, the phage was able to kill the bacteria

Another interesting virus that's currently being studied is known as GBvirus C. Over a billion people alive today have already been infected with it at some time in their lives

And a few experiments suggest that when someone infected with HIV also gets infected with GBVC

the spreading of HIV might decelerate. Some experts also believe that GBVC might help a person survive Ebola, although there's

not a lot of data on that at the moment