Regular readers will know that I am enthralled by the microbes that share our lives, collectively known as the microbiome. I’m even writing a book about them and the influence they exert, upon us and the animal kingdom (out in 2016). But I am also antsy about the runaway hype that surrounds the microbiome, and our attempts to manipulate it to improve our health.

This weekend, I wrote an op/ed for the New York Times in which I argue that the quest for a “healthy” microbiome is an illusion, based on a poor and  oversimplified understanding of the complex ecosystems within our bodies. The piece is my attempt to add a bit of nuance to discussions of the microbiome, and