5.) The Wild Life of Our Bodies by Rob Dunn: This book takes a broad look at the role that hangers-on have on human life.
4.) The Psychobiotic Revolution by Scott C. Anderson et. al.: This book focuses on the role that our gut microbiota have on our mental well-being–which increasingly appears to be substantial.
3.) Missing Microbes by Martin J. Blaser: The focus of this book is on how our love of antibiotics in every form– from pills to antimicrobial soaps–is killing us by denying us microbiotic diversity and robustness.
2.) 10% Human by Alanna Collen: Collen’s book addresses many of the same issues as the other books mentioned, but–as the title suggests–it emphasizes the fact that a human has 10 times as many hangers-on of other species as it does cells that are contiguous to the body. (If you’re wondering how this could be, it’s because the human body has some pretty big cells [some macroscopic, in fact] and the bacteria and other single-celled species tend to be relatively tiny.)
1.) I Contain Multitudes by Ed Young: This is probably the most highly-regarded of the books on this subject. It was considered one of the best science books of 2016.