MEET YOUR SECOND BRAIN
Frederik B O Nel (February 2018)
In the magazine, Very Interesting (issue 39, Jan/Feb 2018), an article titled “Meet your second brain” by Robert Matthews, is based on a book called The Mind-Gut Connection (2016, by gastroenterologist Dr Emeran Mayer.
This so-called “second brain” is a reference to our enteric nervous system (ENS), or, what we would describe as our digestive system. The point is that our ENS is in constant communication with our brain by way of the vagus nerve. What happens in our gut and our brain is in constant communication with each other. It seems as if this constant flow of signals between our ENS and brain can influence our decisions, mood and well-being.
There are various theories on how this relationship between our gut and brain could play a role in obesity, clinical depression, rheumatoid arthritis, and even Parkinson’s disease. Our ENS system is made up of 50 to 100 million nerve cells – apparently as many as in our spinal cord. The ENS also contains neurotransmitters (like serotonin) and other biochemicals that are vital to brain activity.
A lot of research is being done on what is known as the microbiome. This refers to a vast array of bacteria, viruses and other organisms that is found throughout the body, but with the biggest and most diverse collection in the gut. Although the task of these microbes is focused on the complex task of digestion, their behaviour in the gut is constantly monitored by the ENS, with the information being relayed via the vagus nerve to the brain.
Questions on the role of our diet in some illnesses is part of this research. Much research also focuses on developing devices that could monitor what is going on in the human ENS over longer periods of time.
There continues to be many unresolved issues and much more research is required to confirm or reject some of these theories. What is important, is that research is looking into these connections.
It is still early days and clear answers remain elusive, even though some of the research dates back to the 1980s. Certainly, some people are likely to jump to conclusions based on the limited information available and will promote specific diets to “cure” depression or many other illnesses. But the information now available indicates that we really should think holistically about how our bodies function and, specifically, about the important link between the human spirit and our bodies.
Vagus Nerve (Insert link to PDF here)