I Contain Multitudes: the Microbes Within Us and a Grander View of Life

By Ed Yong

Published by HarperCollins publishers
ISBN: 9780062368621

Book review by Antonio Gomes da Costa, Independent Consultant - Science Communication and Education, Lisbon, Portugal.

Warning: DON’T TRY THIS AT HOME! (but do read this book and tell people about it!)

If you google “faecal transplant” you might be surprised at the number of sites that come up with explanations of how it may be a good idea to collect poop from someone and place it in the intestines of another person. And if you have some scientific literacy, or just good sense, you will be terrified and rightfully worried that some of the sites offer instructions on how to do this at home, using a kitchen blender and… well, I’ll leave the details for another occasion. The same applies to the many sites recommending vaginal swabs for new-born babies that were born through C-section: some parents are demanding from doctors that they collect vaginal fluids from the mother’s vagina and apply these to the mouth, eyes and skin of the new-born baby; if the doctors are reluctant to do so at the maternity, some parents are taking things in their own hands and plan to do the procedure later, at home.

Before even considering trying any of these procedures – and before refusing them upfront – it is strongly advisable to read I contain multitudes: the microbes within us and a grander view of life, by Ed Yong. It is a fascinating book, a delight to read, and an excellent example of science communication and popularization. And if you read this book, you will know better than trying those things at home.

As the title indicates, the book deals with microbes. We know they are everywhere, we know they cause diseases, some of us are aware they may be useful (think of wine and cheese…), and we know our immune system is designed to fight them. This book shows how wrong we are: they are much more “everywhere” than we realize, a lack of microbes and excessive disinfection will cause diseases, they are not only useful but fundamental to our survival, and our immune system is not designed to fight and kill them, but rather to carefully ensure that a healthy mix of microbes thrives in our bodies.

The book deals with microbiomes: the whole ecological landscape of the micro-world, the dynamics of populations of different microbes, and how they flourish, evolve, change and adapt to the life in our guts, our skin, armpits, belly button, feet… After reading this book, we become aware how microbes are influential, needed and vitally important, how they are such an integral part of our physiology and how possibly they affect the way we behave. When we say “we”, we should in fact be referring to an entity that includes all the microbes that are living within us. We do contain multitudes.

Further than a brilliant and fascinating exploration of the microbiomes in us (and around us), this book is a very good example of how to do science popularization. Each discovery and each ongoing study is accompanied by a vivid description of the scientists and their work: in a few sentences, Ed Yong gives us a glimpse of the scientists’ personalities, of what drives them in their quests, how they relate with their peers, and of the efforts and sometimes extreme experimental approaches they use. While reading it, one realizes that the book is not simply about a subject, it is really about research: Ed Yong is showing us a recent scientific field that has “exploded” when new technological and scientific approaches made possible to quickly identify all the microorganisms existing on a sample without having to grow them in petri dishes (a process that makes it difficult, if not impossible, to reveal all the microorganisms, since it selects for those adapted to the growing conditions). Most of what we are reading is relatively recent and the author does make it abundantly clear that many of the things he describes are still uncertain, that there are contradictory claims and confusing data – it is, after all, a book about science in the making.

This does not diminish the interest of the book, quite the contrary: we feel accomplices of the whole endeavour, our curiosity is sparked, and after reading the book we start looking at the news about microorganisms and microbiomes in a completely different light. For instance, we are now equipped with enough knowledge to understand why faecal transplants are being tested in hospitals and are a new hope for treating certain conditions; and we understand that during birth the babies are “seeded” with the vaginal microbes of the mother and that this may be very useful, but we also understand that there are a lot of things that scientists and doctors are still figuring out regarding this subject.

For science communicators, this topic and this book may be good starting points for a much-needed debate: ongoing scientific studies are now easily accessible to everyone, which is something we have rightfully been fighting for; but sometimes this has a consequence that ongoing research results and possible (notice: possible) conclusions are prematurely taken as facts – many develop into “miracle cures” – and become very dangerous fashionable practices. How to deal with this?