I first began posting about beneficial viruses at the following location: https://www.growspice.com/Beneficial-virus-helps-plants-including-tomatoes-tolerate-high-heat-td1765.html
This thread is for more articles about the beneficial impact of viruses:
The above article tell about how viruses helped us be able to digest starch, among other things.
I read another about how they help (not as in past tense) proper intestine development. I don't have the link offhand.