The microscope gave humans our first glimpse into the hidden world of microbes. Then along came germ theory, and war was declared against these invisible organisms.
Fast forward to today and we're starting to realise how much we need bacteria and yeast to stay healthy; they could even be important to our mood and mental health.
In his book I, Superorganism (Icon Books) the science writer Jon Turney goes on a journey through our inner ecosystem. On the way he finds out there's lots to love about our the hidden microbial communities we play host to.