A pithy, vibrant, accessible exploration of the least-understood organ in the human body, broken down into 60 bite-sized topics.

The human digestive system, or gut, can be understood like the hole of a doughnut. In other words, it's not really us at all, but a vast ecosystem of bacteria, yeasts, fungi, viruses and other micro-organisms collectively weighing up to two kilograms. And the gut does a lot more than simply break down our food it impacts our immunity, stress levels and even our moods. The connection between the brain and the gut is one of the most exciting research areas of biology today, changing the way we manage our mental health. This book traces our understanding of the gut, from ancient medicine to modern day, examining the enormous impact this little-understood organ has on our lives.