You've probably heard we're in a spot of trouble as a species due to our over-use of antibiotics. Hard to say how we'll save ourselves, but one of the big research directions are bacteriophages, which are tinier creatures that eat bacteria.
Here's a crowd-pleasing animation video explaining bacteriophages that, well, probably everyone should watch: Video (rumor is, this was funded by the Bill & Melinda Gates Foundation).
The idea of exploiting bacteriophages isn't new (is there anything new under the sun?) - the Russians have been doing it for about a century. (Notably, the history of science in 20th century Russia was a bit high-variance - ranging from brilliant work that helped them pioneer space travel to tragically-flawed dogmatism, perhaps most famously and politically, that of the anti-geneticist Lysenko).