Since the advent of germ theory in the 1870s, our approach to dealing with microbes has been to eradicate them whenever possible. The result has been an upsurge of antibiotic resistance and a host of other disorders that result from the disruption of our microbiomes: diabetes, obesity, depression, all kinds of inflammatory diseases.
But most bacterial infections are caused by bugs that live peacefully with us most of the time, and only flip into attack mode in response to a disturbance. New therapies – and some old ones – seek to make these bacteria good citizens again rather than eradicate them. Here’s what I wrote for New Scientist (paywall)