Imagine the most complicated situation you could conceivably understand. For each and every discernible component of that situation, imagine a new situation just as complex. Now multiply all of those situations together. Still with me? Of course you’re not! It really doesn’t take much to leave a human brain stultified with incomprehension.

I Contain Multitudes by Ed Yong is a rightly popular book about microbiology. It is that multiplication operation. If you’re doing something "easy" in biology, like seeing how many rabbits get eaten by foxes, it’s amazing how this quickly explodes into some horrifically complex mess. In biology the Lotka–Volterra non-linear differential equations are easy. Relatively speaking. But what if we’re not talking about furry cute things like foxes and rabbits but rather invisible microorganisms. These are the "multitudes" of the book’s title and the complexity just goes up and up. Truly, none of us is properly equipped to even appreciate just how complex the natural world is.

The book is a best effort. It is incidentally a brutal reproach of mankind’s greatest monument to hubris and ignorance: the medical doctor. If you’ve visited one in the last 70 years, you know they are nothing more than sanitized drug dealers. The book doesn’t say that. I’m editorializing. But the book does talk a bit about how dangerous the medical profession’s foolhardy obsession with antibiotics has been. Why has it been so wrong? Because it’s complicated!

Rather than summarize this book, I’m going to let an expert do it.

For my ally is the Force. And a powerful ally it is. Life creates it, makes it grow. Its energy surrounds us and binds us. Luminous beings are we, not this crude matter. You must feel the Force around you. Here, between you, me, the tree, the rock, everywhere!

— Yoda

Just replace "Force" with "microbiome" and you’ve got this book’s message. A message which, while complex to the point of nebulous as mentioned, also seems pretty accurate. If you think you might be interested in learning about some of the marvels of modern microbiology I do highly recommend reading this book. It’s well written and the topic is fascinating.

For me personally, it was a little oppressive. The complexity that this book introduces to many readers isn’t really new to me. San Diego is a strangely backward place, but not when it comes to biomedical research. I have had a front row seat working for research labs for a dozen or so years now. Not only am I familiar with Aedes aegypti mosquitoes from hearing about them in weekly meetings, the lab I work in does another multiplication. It is a structural biology lab. This means that in addition to all the other complexity of biological systems, we’re interested in what every atom, literally, is doing. We’re a computational biophysics lab which is where I become slightly less useless. You could spend a million lifetimes just learning about the tools of the trade.

From my field observations of molecular biologists in the wild I have already absorbed the sense of overwhelming complexity. You see, it’s not just foxes vs. rabbits, or Wolbacia vs. wood lice. What is beyond the scope of this book is that there are many more levels of complexity. How do chemokines and their receptors interact? Don’t forget the near infinite variety of other molecules that complicate the relationship! That’s still not even probing the dark magic of atomic physics itself.

The natural world is overwhelmingly complex. Every person you’ve ever heard of who claimed to significantly understand it is a liar, an idiot, or both. I knew that going in. I even knew about the microbiome. I think the author was even a little reluctant to go as far down the microbial rabbit hole as I’ve gone. I have read Thomas Gold’s The Deep Hot Biosphere: The Myth of Fossil Fuels and I accepted its possible validity right away and have yet to see serious refutations. To me surface dwelling plants and animals are the earth’s extremophiles.

So what to make of it? How is this going to improve quality of life? The book mentions Florence Nightengale recommending, 150 years ago, something that is just now apparently being rediscovered to the horror of hospitals everywhere: for best convalescence, it might be good to open a window and get some fresh air. What a concept! My advice has been steady for a long time and it all seems coherent with the well-being of my multitudes. Live a wholesome life. Balance temperance with indulgence. Avoid filth but also avoid obsessing over it. Keep your mind active with wholesome pursuits. Eat only food. Avoid unnatural small molecule chemistry. Create a lifestyle that is physically active that you can maintain your entire life. Listen to your body. And, yes, get plenty of fresh air!

UPDATE 2018-05-14

See my long list of interesting miscellaneous things to speculate about related to microbiomes.

UPDATE 2018-12-14

Here is a recent article discussing tests of Thomas Gold’s conjectures and finding exactly what he predicted they would find, i.e. if you drill very, very deep holes, rather than seeing life fade away from its terrestrial comfort zone, you find that it’s richly distributed throughout the entire earth’s mass (which we can access).