"This book discusses the community of microbial species (the microbiota, microbiome), which inhabits the large bowel of humans. Written from the perspective of an academic who has been familiar with the topic for 40 years, it provides a long-term perspective of knowledge about this high profile and fast-moving topic. Building on general ecological principles, the book aims to help the reader to understand how the microbiota is formed, how it works, and what the consequences are to humans."--Provided by publisher.