You might have heard of your microbiome, but did you know you also have a virome? That’s right, there are more than a trillion active viruses within you right now.

Viruses exist in every organism, in every environment. There are at least ten times more viruses on Earth than all other biological entities combined.

A virus is a tiny packet of RNA or DNA, about 1500 times smaller than a grain of salt.

They lack the ability to reproduce or the ribosomes to make energy. Many scientists don’t even consider them to be alive. They can only flourish within the cells of their hosts.

When a virus enters a cell, its genetic code instructs the cell to replicate it. Not really reproduction, but duplication.

When the cell is spent, it releases these newly created viruses to repeat the process.

Most viruses are symbiotic and beneficial to the host.

Some attack bacteria, as in our gut. Some provide genes the host can use, like those that protect plants from drought or cold. Others leave behind bits of genetic code that have helped hosts evolve, something we talk about on other episodes.

Pathogenic viruses harm or kill the host, but there are only about 200 that infect humans, like the coronaviruses that cause the common cold and COVID-19.

Though these rogue actors have given viruses a bad name, the truth is, we couldn’t live without our friendly virome.