I got a lump in my throat. Gut feeling. Trust your gut. I feel sick to my stomach. Hard/bitter pill to swallow. Gut instinct. Butterflies in your stomach. Emotional eating. Gut-wrenching. Misery guts. Gut reaction. You’ve got guts. Kick in the guts. Hate your guts. Love your guts. Hangry. Comfort food. I don’t have the stomach for <something>. Eat your heart out!
Look at all the idioms we have in the English language that relate our gut to our emotions and behaviours! The list could keep going, and I’m sure that there are even more phrases in other languages around the world… so it’s clear. There has to be some sort of connection between the gut and the brain. We call this the gut-brain axis. The gut is also referred to as the “second brain”.
First of all, what is the “gut”? Sounds pretty vague, doesn’t it? The gut, or digestive tract, is a long tube that starts at your mouth and ends at your anus. Gut health has been all the rage these last few years, and mainly refers to the small and large intestines – this is where all the magic happens.
So, how is the gut and brain connected? There is a complex network of nerves that are embedded between the layers of the gut tube, collectively known as the enteric nervous system. These nerves all join together to form a larger nerve called the vagus nerve, which travels up to the brain to pass on messages from the gut. This communication system goes in both directions – the brain can communicate back to the gut.
My knowledge of the gut from medical school is outdated, so I’ve taken it upon myself to read recently published books and articles from medical journals, and break it down for you (pun totally intended.. and yeah, you’re welcome).
When we think of the gut, we think about digestion of food, absorption of nutrients, and excretion… but this is an antiquated view. We now know that the gut is responsible for so much more than that, including skin health, immune function, hormonal balance, sleep regulation, and mood.
A Bug’s Life
You may have heard the word “microbiome”, as well as wondered what all the fuss is about kombucha and probiotics that all these hipsters are consuming… and what on earth is kefir? And how does this have anything to do with the gut?
The microbiome describes the population of “good” bacteria that live in your gut – a hundred trillion of them. They are involved in various regulatory systems that are responsible for our overall health and wellbeing, so we need to look after these tiny little friends. Whenever you take antibiotics for a bacterial infection, it wipes out both the good and bad bugs. However, the good news is that you can increase the amount of good bacteria.
This is where the probiotic stuff comes in. Probiotics are live microbes that can be found in yogurt, kombucha, kefir, and other fermented foods. They’re a great way to top up your good bacteria. There are also prebiotics, which are high fibre foods that our bodies can’t digest, but provide fodder for the good bacteria.
In the process of breaking down prebiotics, the microbiome produces short-chain fatty acids that are essential for our metabolism of sugars and fats, and therefore diseases like type 2 diabetes and obesity are linked to imbalances in the microbiome.
For me, the most interesting thing was learning about the role of the microbiome in serotonin. Depending on the source you read, 90-95% of the body’s “happy hormone” – serotonin – is produced in the gut, with the remainder made in the brain. The microbiome activates the transport protein that releases serotonin from the gut into the body’s circulation. Serotonin is not just important for good mood, but also helps with sleep, cognition, and appetite (and therefore weight management).
This made me understand why the life I was (not) living when I was working my guts out at the start of the year contributed to my burnout, and explained all of the physical, mental, and emotional symptoms I suffered from (and still do).
So, how can we look after our microbiome, so that it can look after us? Three things: a healthy and varied diet that includes pro- and pre-biotics, adequate sleep, and reduced stress – none of which I was able to do because of the workload that was forced upon me… which leads me to introduce you to two future posts I’ll be writing:
- The ugly side to becoming a surgeon: the preamble to deteriorating health
- How stress leads to physical and mental illness
I hope that this post has been informative and made you appreciate the magical world of your microbiome.
Take care (of your gut),