Please note that you are acquiring a summary of the book. All the author's key ideas are presented in sammari format, which you can read in 30-40 minutes without missing anything important. The summary was prepared for your convenience by the authors of the online library Sokratko. Alanna Collen (Alanna Collen) - biologist, doctor of science, who contracted a dangerous infection in the rainforest and underwent serious antibiotic treatment, which greatly undermined other processes in her body. This motivated her to study the human microbiome. The result of research is this book. This book is intended both for people interested in biology and medicine, and for those who simply want to better understand their own bodies. It details the effect of microflora on human life and its relationship with diseases of the 21st century: obesity, allergies and autoimmune diseases.