‘Everyone is whizzpopping, if that’s what you call it,’ Sophie said. ‘Kings and Queens are whizzpopping. Presidents are whizzpopping. Glamorous film stars are whizzpopping. Little babies are whizzpopping. But where I come from, it is not polite to talk about it.’
- Roald Dahl, The BFG
Before we go any further, I have to tell you this: I hear these little voices, and they tell me what to do. I can see your eyes dart in bewilderment, so let me explain. You must know that your body contains countless biological machines. They’re of different shapes and sizes, and they coordinate in an exquisite manner to keep you alive. But although the machines in your body are largely similar to those in anyone else’s, human behaviour is notoriously unpredictable. You’re likely to find that two people will respond to exactly the same circumstances in vastly different ways. Machines don’t strategize - they just do what they’re designed to do. Our bodies are just meaty marionettes, and your strings are not pulled in the same manner as mine. What exactly is it in you that makes you behave differently from me? Your eyes are a bit more relaxed, but your nose still shrivels in confusion. At this point you decide that I must be talking about the brain, and the neurons within. You wonder, with trepidation, if I hear voices in my head. No, the machines actually speak to my other brain. Trillions of them.
In her extraordinary first book, Giulia Enders shines a spotlight on one of the least-appreciated, and surprisingly under-examined, parts of our body, which is responsible for a lot more that we give it credit for. I can’t recall the last time I read something so tightly packed with scientific information, while also being humorous and thoroughly enjoyable. In addition to providing a comprehensive overview of every step involved in digestion, the book introduces us to some tiny friends who are dedicated to making our lives better. Our digestive tracts are little ecosystems, containing around a 100 trillion bacteria, most of which play essential roles in digestion. It is also possible that some of them might make you less depressed, while others could make you fat! There is still active research on the extent to which your gut flora can impact your body, but they cannot do so without the enteric nervous system (ENS), which spans the gut. The ENS, colloquially known as the second brain, is unexpectedly sophisticated, and it sends signals to the parts of our brain responsible for “self-awareness, emotion, morality, fear, memory, and motivation”, thereby playing a key role in shaping our experiences. One of the tenets central to everything that we believe in is that human beings are individuals, capable of independently making decisions. It boggles the mind to imagine that perhaps some of our putatively autonomous decisions may in fact be made in collaboration with things living inside us. Enders convincingly argues that “[o]ur self is created in our head and our gut”.
Unsurprisingly, this book is filled with facts that I was completely unaware of; for example, that saliva contains a painkiller stronger than morphine. That the appendix, long believed to be mostly useless, “acts as a storehouse of all the best, most helpful bacteria”. That the composition of everyone’s saliva is slightly different, and that it can hence be used to test for diseases. That there are broadly three different types of guts (enterotypes), based on the family of bacteria that is dominantly found. I was also intrigued by the fascinating insight that balancing your diet also means balancing your amino acids! And as someone who suffers greatly from travel sickness, it was illuminating to learn that it is likely due to a mismatch between the signals received by the brain, similar to those symptoms experienced as a result of alcohol poisoning, for instance.
Gut is a rare science-themed book I would enthusiastically recommend to a casual reader, simply for its arresting style (“The first thing a sea squirt does after setting up home is to eat its own brain”!). Enders’ text is beautifully complemented by the absolutely delightful illustrations (by her sister, Jill), which depict the inherently weird and wonderful facets of the digestive process. I’m fairly confident that you don’t treat your gut with anywhere near the level of respect that it deserves, or have an appreciation for the complexity of the tasks it carries out. The first step towards rectifying that would be to read (and then re-read) this book!
