Our hygiene practices can have surprising and unintended effects, as this informative and entertaining introduction to the new science of skin microbes and probiotics reveals

Keeping skin healthy is a booming industry, and yet it seems like almost no one agrees on what actually works. Confusing messages from health authorities and ine¬ffective treatments have left many people desperate for reliable solutions. An enormous alternative industry is filling the void, selling products that are often of questionable safety and totally unknown effectiveness.

In Clean, doctor and journalist James Hamblin examines how the health of our skin is influenced by the world around us in unexpected ways. He argues that a major part of the picture has been missing: a little-known ecosystem known as the skin microbiome-the trillions of microbes that live on our skin and in our pores. These microbes are not dangerous; they're more like an outer layer of skin that no one knew we had, and they influence everything from acne, eczema, and dry skin to how our bodies smell.

To determine how this new understanding of skin will change our hygiene and skin-care habits, Hamblin talks to dermatologists, probiotic researchers, allergists, immunologists, estheticians, bar-soap enthusiasts, venture capitalists, Amish people, theologians, and straight-up scam artists. He even experiments with giving up showers entirely, and discovers that he is not alone. Along the way he realizes that most of our standards of cleanliness are less related to health than most people think. Embracing a new definition of "clean" could mean doing much less, saving time, money, energy, water, and plastic bottles in the process.

Lucid, accessible, and deeply researched, Clean explores the ongoing, radical change in the way we think about our skin, introducing the emerging science that will be at the forefront of health conversations in coming years.