Ever had that feeling in your gut that something isn’t right or the feeling of “butterflies in your stomach”? Well, those feelings might be more literal than you think. Introducing you to the fascinating connection of our Gut-Brain axis filled with heaps of unique bacteria and wonderful coordination between our gut microbiota and brain to ensure an easy and happy digestion for us humans.
Our journey starts from the introduction of the Gut-Brain Axis. This complex bi-directional pathway connects the Central Nervous system to the Enteric Nervous system. The connection is not only anatomical in nature but it also involves the endocrine, metabolic as well as immune route of communication.
Moving onto our next stop, we have our little second brain, which scientists call the Enteric Nervous System. A little secret: It’s actually not that little. The enteric nervous system is 2 thin layers lining the GI tract from the esophagus to the rectum. It comprises close to 600 million neurons that help in a multitude of functions ranging from motor to secretory in addition to absorptive and sensory. Moreover, its ability to work in a semi-independent state from the brain has earned it the moniker “second brain”.
Our ‘second brain’ and our actual brain are always on call with each other, with our brain helping the ENS perform its job efficiently and smoothly. The landline, or in this case the bodyline, connecting the
two brains is the Vagus Nerve, additionally known as the 10th cranial nerve. Starting its journey from the medulla oblongata, it takes its first stop in our lower brainstem before moving to the rest of the body. This is a crucial part of our connection between the 2 brains as it is the primary information carrier, any damage to this would lead to drastic consequences.
While our ENS may not be able to do basic maths or compose symphonies, it does control the body’s digestion, from managing the release of enzymes to the movement of the bolus from the esophagus to the rectum. For quite some time, scientists used to believe that our mental health was intertwined with our gastrointestinal tract. They thought that a degradation in our mental health caused us to experience a dire change in our gut health as well.
Recent studies done by Johns Hopkins, Harvard, and Loma Linda University as well as some leading researchers in the gastrointestinal field such as Elizabeth Thursby, Xiao Chen, Michael Schemann, etc, have their research pointing towards a theory that baffles us. Their research suggests that any disturbance in our gut microbiota can also lead to a disturbance in our mental health such as depression, anxiety, insomnia, etc. This seems to be the opposite of what we have seen up until now. Truly a captivating discovery.
Research on Irritable Bowel Syndrome (IBS), done by Johns Hopkins, has found evidence that IBS may send signals to the CnS which causes us to have mood changes. This evidence is still untested, but this does create a new foundation for us to build upon. This, while somewhat inadequate, explains how people with IBS develop depression and anxiety more than the general population, an increase of around 30-40%. This can also point toward the fact that some medicines that upset our gut microbiota can, instead of improving our mental health, cause us more harm than good.
While these theories are still in their testing phase, we can see that this path holds countless secrets about our body and is a step towards understanding our mind and body more effectively and efficiently, a path towards understanding the magnitude of the complexity of the homo sapiens.