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  • Masarat Jilani

What do you mean I have two brains?

Everyone is born with two brains: the brain in their head… and their gut brain! Our language is filled with phrases such as “I’m gutted” or “gutsy” which all link the gut with emotions, and as it turns out, it’s not just a figure of speech. However, scientists learnt about the importance of the gut brain and how it communicates with our brain not that long ago. Nevertheless, it’s fair to say that this unique connection could have the power to change the way we approach diseases forever!


What is the gut-brain connection?


Your brain and spinal cord form the central nervous system, whereas your gut has a collection of nerves called the enteric nervous system. The enteric nervous system is your second brain - experiments have shown it can act independently, even when its connection to the brain is severed. The enteric nervous system contains 500 million nerve cells, which is 5x more than those in the spinal cord, supplying the rest of the entire body. Our two brains communicate with each other through a mechanism known as the gut-brain axis. They “talk” through hormones, the immune system and your nerves. This way, your brain can control the gut and your gut can also control the brain. Doesn’t this give the phrase “following your gut” a whole new meaning?!



Historically, we might have thought the gut was like a machine which digests our food and produces waste. This begs the question - why would such a simple system need its own brain?

Both the gut and the brain use the same chemical messengers to control how nerves send signals throughout the whole body. For example, serotonin, also known as the “happy hormone” (since it can combat depression), lives mainly in the gut! Another hormone, called dopamine (which is involved in motivation and addiction), lives 50% in the gut, too. But why do these hormones, associated with high-level mental functions such as mood and motivation, live in our food processor?


The answer may lie with another feature of the gut which has been exciting scientists and patients alike. And that is the gut microbiome.


The gut-brain microbiome axis


Just to blow your minds further (get it?) - most of your body is formed of bacterial cells rather than human cells. That’s right - most of you actually is bacteria! These bacteria, along with other microorganisms, including fungi and viruses, live on your skin, lungs, inside your mouth and many other places. And the largest group of these microbes live in the gut. This may be why the gut requires its own brain - to send signals from these trillions of bacteria back to the brain.


Microbes have a bad reputation in causing illnesses and diseases (and even worldwide pandemics). But you might have heard about “good bacteria”, and it is these bacteria along with other microbes which live in the gut. The collective genes from all these gut microbes form a microbiome and help us stay healthy. However, an imbalance in this microbiome may cause disease. It’s actually these microbes which have been shown to form the chemical messenger like the happy hormone which controls our mood.



The gut microbiome receives signals from both the gut brain and the brain itself. It also communicates back and helps keep the systems in check. This is why a brain imbalance can affect your gut and a gut imbalance can affect your brain. For example, stress and anxiety release chemicals from the brain that react in the gut by changing the microbiome. This in turn causes the microbiome to decrease the important chemicals it produces. These then feedback to the brain and can alter our behaviour as well as causing local effects in the gut, such as cramping and discomfort. The result is an imbalance of chemicals in the gut, which may be linked to disorders like irritable bowel syndrome (IBS).


Addressing the gut-brain link to help IBS


Ever heard of the phrase “you are what you eat”? A recent research paper from the University of Oxford showed that the microbiome of people who were more sociable was different from those who were not! Could this be a case of people eating different foods which then makes them more sociable? Or could it be that a sociable brain alters your gut bugs? It is probably a bit of both. But it is crazy to think that the bugs in our gut can shape our personality!


The knowledge about the second brain and the microbiome has the potential to change the way we view healthcare, as it may be imbalances in this communication system which cause a range of diseases. So far, the microbiome has been shown to play a role in the immune system of babies and possible roles in autism, sleep, anxiety and depression. Crucially, it could contribute to causing IBS.


If you want to learn more about the gut-brain connection, and more importantly, use this knowledge to maintain your IBS, try Zemedy. With a 6-week CBT program designed specifically for irritable bowel syndrome, Zemedy addresses the gut-brain link and helps you tackle physical and psychological symptoms of IBS from within.

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