Thoughts on “I Contain Multitudes”

This book talks about microbes in great detail.
* Microbes are our oldest, truest friends, when they’re not killing us. They don’t just help us digest our food, but they affect just about everything in our bodies, including our mood. They can even help us cope with stress.
* Microbes don’t just help us, they also shape us. There’s a complex relationship between our immune system and our microbes. Our microbes calibrate how alert our immune system is: if it’s too relaxed you get infections and if it’s too strict, autoimmune disease. And in turn, our immune system keeps our microbes in check, keeps their numbers within range and evicts undesired inhabitants.
* Mother’s milk is super important for the development of babies, and again, this partly has to do with microbes. It contains a complex sugar which is used to feed -not the baby!- but the baby’s gut bacteria. In turn the baby’s fed and protected by the bacteria. The bacteria also releases a nutrient called sialic acid, which helps the brain grow faster during the first year of its life. Of course, after reading this bit of information I asked my mom how long I was breastfed: 6 months. Make what you will of this information. (My sister says: adam olana çok bile.)
* How did we come to know all this stuff? Well, mice. Scientists grow mice in completely sterile environments, free of all microbes. These mice turn out pretty troubled. Messed up immune systems, anxious, prone to infections and autoimmune disease. You name it. Then they transplant different microbes into these sterile mice and see what happens. For example: they transfer microbes from obese mice and see if these lab mice also become obese (they do). A note here: yes, obese people and lean people have different gut microbe communities. Lean people cultivate good gut microbes which help them put on less weight. But they still have to take care of the microbes by feeding them the stuff they like, healthy stuff. Especially fiber is super important, it seems. If you starve your fiber-hungry bacteria, they start attacking the mucus on your gut walls. Luckily I always put oats in my smoothies.
* There’s a trade-off between infectious and allergic disease. If you create a super sterile environment by constantly disinfecting your house, you won’t have the right microbes around, and your immune system will be panicking over nothing, like pollen. This comic comes to mind (bear with the Turkish, I’m sure you’ll figure it out):

* Eating probiotics don’t help with much it seems, at least at the time this book was written. They help with diarrhea, reduce the side effects of taking antibiotics (mass destruction for your gut bacteria, by the way), and necrotising enterocolitis, which is not something you need to worry about unless you are currently a premature baby. And that’s it. So, unless you really like it, you can stop with the probiotic yoghurts and the kefir and the kombucha (I love kombucha). What makes more sense is to take prebiotics, which are the stuff that feed your gut bacteria and help them flourish.
* What does work though is a good old poop transplant (don’t do this at home though). It’s the process of taking poop from a person with healthy gut bacteria and transplanting the poop directly into the colon of the patient. The results are promising, It cures some crippling bacterial infections at unprecedented rates. All you have to do is keep an open mind really. Scientists have now moved on to removing the poop part and just transferring the healthy microbiome via a pill. It’s whimsically called the RePOOPulate. It’s speculated that in the future, we will have personalized versions of these.
* One step further is engineering synthetic bacteria with the genomes we need. This is where it gets real sci-fi, but also, I can see it happening. Your own personal E. coli, a superbug to give you all the nutrients you need, and fight all the pathogens. Throw in some anti-anxiety genes too, would ya doc? As the saying now goes: An e. coli a day keeps the crazies away.
* This book is a mixture of fascinating and dull. If you’re not obsessed with reading a book from start to finish, then I recommend starting from the Body Builders chapter. Skip The Long Waltz, Mutually Assured Success and Allegro in E Major, unless you’re interested in the joint evolution of microbes and the animal kingdom. Personally, I found these chapters a bit slow, and the anecdotes I mostly already forgot. I guess I’m a self-centered human-centered gal, after all.
* I think with this review I deserve an “Overselling the Microbiome” Award as well. Yes yes I know. Microbes are not necessarily good, they’re not bad, they just are. And they’re everywhere. But they are pretty neat, aren’t they?