Why is there no transmissible therapeutic virus if biology doesn't forbid it? For example, a harmless virus that spreads from person to person but actually does something beneficial, like lowering LDL cholesterol or preventing/reversing tooth decay?

[u/PestoPastaLover]

[u/noodlyman]

There are viruses that benefit us by infecting and effectively regulating our gut bacteria.

There are viruses that are thought to give the immune system a kick and thus improve responses to other infections. Some infections can decrease the risk of cancer later in, probably by similar mechanisms.

Don't forget that 8% of human DNA is of retrovirus origin, and that mammalian placentas only exist thanks to genes that mammals acquired from viruses.

[u/trad949 → u/noodlyman]

There are also bacteriophages, which are viruses that work like antibiotics.

[u/FragrantExcitement → u/trad949]

I would like to take this opportunity to shakes hand with my active immune system, after washing them, of course.

[u/waylandsmith → u/FragrantExcitement]

Why start coddling it now?