I Contain Multitudes

 This was a pick by one of the two book groups I’m in and I’m wondering why. Published in 2016, it’s already well out of date. Reading it is like coming across someone’s newspaper clippings on the subject of microbes they compiled from 2010 to 2015. Much of what’s in this book has been covered and updated in the semi-popular press.
 There are other problems with it.
• The title is misleading. You think it’s going to be all about the microbes humans carry inside them, but at best, just twenty percent of it’s about that. Most of it is about microbes in general, and we learn a lot about microbes in insects. For some reason, there’s a long part about the degradation of coral reefs, an important topic, yes, but it’s been well covered elsewhere.
• There are far too many notes (376 over 264 pages), and you don’t know which ones add enough to the text to bother flipping to versus ones that just provide citations without reading them. You can try looking at the notes before beginning a chapter and remembering when to go to the ones you should read, but that’s hard. (Was it 23 or 25?) Many of the notes could have easily been incorporated into the text without breaking the flow or slowing things down. Doing it the way Yong has makes the book seem like a weird mix of academic writing and popular science writing. He clearly tried to make it readable to the layperson, which you can tell by the title and by the way all the chapter titles are either directly or derived from familiar phrases.
• There are more errors and typos than I like to see in a professionally published book like this, but that’s the old crank in me speaking. For much of one chapter, the note numbers and the notes don’t match.
• Much of what is advocated in this book is laughable now due to the pandemic, as sound ideas as they may be. It’s unlikely that anyone these days will try to incorporate more bacteria into their lives than they do now. In one passage, Yong even suggests that cleaning toilets as often as we do does more harm than good, a concept no single man should ever hear.
 When the book is good, though, it is informative.
 An excerpt:

To control a microbiome is to sculpt an entire world—which is as hard as it sounds. Remember that communities have a natural resilience: if you hit them, they bounce back. They are also unpredictable; if you tweak them, the consequences ripple outwards in capricious ways. Add a supposedly beneficial microbe, and it might displace competitors that we also rely on Lose a supposedly harmful microbe, and an even worse opportunist might rise to take its place. This is why attempts at world-shaping have so far led to a few magnificent successes, but also many puzzling setbacks.

Years ago, I read [b:Life On Man|9347542|Life On Man|Theodor Rosebury|https://images.gr-assets.com/books/1437958401s/9347542.jpg|3805548] by [a:Theodor Rosebury|1602817|Theodor Rosebury|https://s.gr-assets.com/assets/nophoto/user/u_50x66-632230dc9882b4352d753eedf9396530.png]. (and also his [b:Microbes and Morals|3971855|Microbes and Morals|Theodor Rosebury|https://s.gr-assets.com/assets/nophoto/book/50x75-a91bf249278a81aabab721ef782c4a74.png|4017612]) yet I remember little about them. I remember liking them (why I read two of them). I bring them up because Mr Roseburry is frequently quoted in I Contain Multitudes, a book that is in a very real sense it's predecessor. Interestingly, Rosebury was a scientist and researcher while Ed Yong is a journalist yet Rosebury is the better writer of the two (if I recall my reading experience correctly). I say this because at times Mr. Yong gives too much detail for a lay reader such as myself and I found it hard to follow what I probably didn't need to follow at all.

There is so much I learned from this book. Multitudes, perhaps. Much has been discovered since Rosebury's day thanks to advances in genetics technology, primarily gene sequencing and genomics. (The one review I read of Microbes and Morals on Goodreads declared it as "dated" though my guess is that the reviewer was talking more about changes in morals than in our knowledge of microbes)

Still, the most surprising thing about this book is how it changes our view of who we are in the same way Roseburry's did (which didn't last and I needed it to be done again.) Only about 50% of our cells are "human," the remainder belonging to various colonies of microbial life without which we wouldn't be able to survive. For example, they are part of our immune system and our digestive tract. They evolved along side us in cooperation with us (preceding us for millions of years) and yet we tend to think of them as enemies, characterizing them by the tiny percentage of them which cause disease. Even as I sit here typing on a computer keyboard that is swarming with them, there are millions more microbes hanging out on my face and hands, living in the forest of my hair and the tropic beach of my mouth crossing the unpatrolled borders of my lips like undocumented aliens when I breathe in and out. We continually exchange our microbes with strangers, on light switches and doorknobs, and with intimates more directly in other ways.

One of the reasons people become ill in hospitals is not merely because of the proximity to sick people but because the internal environment is over-cleaned removing those microbes that protect us. The same antibiotics that kill the germs that make us ill also make us more vulnerable to an influx of different pathogens from which we previously had been protected. In fact, those toilet seats that are sanitized for our protection soon after have more bacteria than before they were cleaned because they lack the "good" microbes that had been killed of in the sanitizing process. Florence Nightingale, Yong tells us, would open windows in hospitals because she noticed that the health of patients near them would improve. We now know that this is because it allows external bacteria into the oversanitzed environment.

Along with this change in how I view myself (and my cats) I learned about the kinds of research being done, e.g. the effects of gut bacteria on anxiety and depression, the project to eliminate dengue fever, studies investigating the relationship of our microbial partners to hypertension and obesity, how the rise in autoimmune diseases my be related to the eradication of many childhood diseases.

I recently tried to discuss some of these ideas with a germaphobe of my acquaintance but he found what I was saying toxic and refused to listen. Don't be like him. Read this book.

I'll never think of bacteria the same way again.
We tend to think of bacteria as contaminants, as carriers of disease, something to be eliminated as much as possible. Yong helps us see them in a much different light: bacteria comprise most of the life on this planet; they're everywhere, and only a small fraction of bacterial species cause us harm.
Since bacteria are ubiquitous, it makes sense that evolution would have made use of them. Given how versatile bacteria are, it's no wonder that many organisms harbor them and make use of them to digest food, or produce other important chemicals. You can look at your intestinal flora as a garden or a farm, where you provide food and shelter for bacteria that help you digest, or crowd out harmful bacteria. In fact, we can even go farther and see certain collections of bacteria as separate organs, ones that have been outsourced to a different species, and can sometimes be upgraded, replaced, or discarded wholesale.
But of course biology is much messier than that, and the relationships between living beings aren't as neat as the above may suggest. Nor can pairs of living beings always neatly be classified as "allies" or "enemies".
With his characteristic enthusiasm and clarity, Yong guides us through some of the complexity and wonder of this microscopic world, and I, for one, have a new appreciation for microbes.

One weakness, I found, is that for all the discussion of what bacteria do, the book doesn't really show what they look like. Perhaps the color plates in the middle of the book can be updated in the next edition to maybe show fewer mice and pangolins, and more bacteria.