Ed Yong, author of 'I Contain Multitudes'

There are billions of microbes both in and on our bodies. These invisible organisms form complex ecosystems, which are passed on to us as infants through breast milk, help digest food in our guts, and may even be correlated with a growing list of health conditions like obesity, chronic fatigue syndrome, and autism. It’s no exaggeration to say that human life would not be possible without the microbiome. Science writer Ed Yong has been reporting on the microbiome for over a decade, and has just published his first book, ‘I Contain Multitudes: The Microbes Within Us and a Grander View of Life.’ In this conversation with producer Mike Osborne, he reveals the evolutionary roots of the microbiome, what we know – and don’t know – about microbiomes across the human population, and how we as humans both create an imprint and are imprinted upon by the microbes in the environment all around us. Photo credit: Urszula Soltys