Ed Yong‘s I Contain Multitudes gives you the secret tour of the amazing world of beneficial microbial-host interactions and the passionate, quirky scientists driving the work. The importance of microbes to humans hit the media with a superhero-sized *TWACK* 5 to 7 years ago, when data from the Human Microbiome Project began to be published. Since then, the human microbiome has been implicated in everything from obesity and diabetes to anxiety and autism. Scores of books, good and not so, have been written in these early years of the microbiome, yet they all focus on the HUMAN microbiome. As a science blogger for National Geographic and writer for The Atlantic, Ed became engrossed with microbial-host interactions. If you’ve read a recent article on the human microbiome, chances are it was one of his. Here’s the secret  – people have been studying microbial-host interactions in insects, squid, plants, lichens, corals, and other mammals – for centuries! We often know MORE about how these other microbes interact with their hosts during development, on a molecular, cellular, ecological, and evolutionary aspect than we do with human-microbe interactions. In fact, it’s this amazing field of non-human-microbe interactions that is the foundation the human microbiome work often stands upon. Clearly, Ed Yong has become as entranced by these non-human symbiosis stories as those of us who have been working on these symbioses for decades.

Multitudes of Interactions

I Contain Multitudes opens up the world of microbes and their larger hosts to the world. Ed writes eloquently about everything from the coffee berry borer, an insect that eats coffee beans due to its gut bacteria that detoxify caffeine, to the luminous relationship between the Hawaiian bobtail squid and its Vibrio mutualists. Ed takes the reader on tours through many research labs including aphid-Buchnera-infested greenhouses with Nancy Moran, germ-free mouse facilities with Jeff Gordon, and a microbial-focused tour of Chicago with Jack Gilbert. Through these tours, he not only accurately captures and relays the science, but also the passion and excitement of the scientists. I laughed when he described Takema Fukatsu as “an infectiously enthusiastic entomologist hell-bent on studying every insect that exists”. Dr. Fukatsu most certainly is and is well on his way. As the Fukatsu lab studies these different insects, they have upended many of the dogma of insect-bacterial interactions and expanded our understanding of different strategies microbe-host interactions employ. It is rare to see the enthusiasm, drive, and passion of scientists described so well.

New Tales for a New Century

The aphid, bean beetle, squid, and other amazing symbioses studied in great detail today were first mentioned in Paul Buchner’s book Endosymbiosis of Animals with Plant Microorganisms. Buchner’s book is the ultimate fairy tale collection of the symbiosis research done from the first part of the 20^th century. As a first year doctoral student, I read about the olive fly-Erwinia symbioses examined first by Petri in 1909. I knew immediately I’d found the symbioses to study for my dissertation. I Contain Multitudes is the symbioses fairy tale collection of the 21^st century. Ed Yong takes the reader on a journey through the current state of symbiosis knowledge and identifies some of the gaps that remain. I Contain Multitudes will certainly entrance a new generation of scientists and non-scientists with its fabulous, yet accurate storytelling.

Without sounding like a textbook, Ed teaches the readers fundamentals and definitions of the field of symbioses and rightly puts us in our place as merely a habitat for microbes. While many of the interactions Ed highlights in this book are beneficial ones, he emphasizes that not all symbioses are beneficial. Symbiosis is simply the living together of two or more different organisms. This simple definition gets misused frequently, so it’s nice to see symbioses discussed accurately. For microbes, the situation makes a difference. Microbes aren’t heroes or villians. Cinderella is in a sparkly dress at the ball, but in sooty clothes at the fireplace. Same person, different situations. As Forest Rohwer is quoted in the book, “When you die, they’ll eat you. They don’t care. It’s not a nice relationship. It’s just biology”. Microbe-host interactions are “just biology”, but they are fascinating and provide insight into how our world evolved and continues to change.

Stories of Swapping Genes and New Powers

Yet I Contain Multitudes is more than a collection of symbiosis fairy tales and their storytellers. Ed Yong delves how symbiotic interactions change over time as microbes and hosts come together and change due to their interactions. Stories of horizontal gene transfer, genes being moved from one organism to another, explains the how bacteria can allow their hosts to quickly gain new abilities. A gene for degrading seaweed that was first found in the gut bacteria of Japanese people, entire genomes of viruses that help parasitoid wasps feed on their caterpillar prey, and many other stories. Throughout the book, Ed embraces the process of science and the many questions that remain. One such example is with Ed’s favorite bacterium, Wolbachia. Julie Dunning Hotopp, my post-doc mentor, found an entire Wolbachia genome inserted into a Drosophila fruit fly genome. Although the bacterial genome is transcribed, what the bacterial genome does within the fly is still unknown.

I Contain Multitudes is a beautiful balance between interesting natural history of symbioses, our current state of knowledge, and the exciting path left to travel.  It highlights the importance of microbes not only to humans, but that of a wide variety of organisms and our planet as a whole. Additionally, it has extensive footnotes, citations of the scientific literature, and is indexed extremely well. This additional level of detail makes I Contain Multitudes an ideal springboard for book club or classroom discussion or solitary contemplation. Whether you need an intriguing new non-fiction book for bedtime reading or a book to recommend or use with your classes, I Contain Multitudes should be at the top of your list.

For a sneak peak of a few chapters:

Breast-Feeding the Microbiome – The New Yorker

Microbes have no morals – Aeon

How Miraculous Microbes Help Us Evolve Better, Faster, Stronger – The Smithsonian

The publisher provided me with a copy of the book reviewed above. Any links within the post to purchase the books are Amazon Affiliate links. Whatever you purchase at Amazon within 24 hours of clicking on the affiliate link will provide a small commission (less than sales tax) to support the costs of maintaining this blog.