Biologist Alanna Collen's remarkable work summarizes the latest research on the human microbiota and their far-reaching effects on our development and health.

We are just beginning to learn about the incredible world inside our intestines and its profound effect on our physical and mental health.

Could many of our modern ailments – obesity, asthma, hay fever, diabetes, and depression – be affected by the balance of microscopic organisms that reside in our gut?

In 10% Human, British biologist and science writer Alanna Collen opens the door to the world of our microscopic inhabitants.

Drawing from the latest research and her personal experiences, Collen explores our coevolution with microbiota and their complex role in our physical and mental wellbeing.