Gut-Health Brain Axis: Uncovering the Link

The linkage between brain functions and intestinal functions has frequently surfaced as a popular topic in the wellness industry. In the past 10 years, numerous research initiatives were undertaken to investigate the Gut-Brain Axis. So, let’s talk through some of the research findings.


The National Library of Medicine published results of a study showing that 95% of 5-HT receptors (5-hydroxytryptamine receptors), or serotonin receptors, are produced in the gut; Since serotonin regulates your mood, researchers recognized that mood and cognitive functions are related to the digestive tract. Capitalizing on this discovery, researchers looked more deeply into the enteric nervous system, a quasi-autonomous part of the nervous system which supports digestion and the GI tract.


What can we learn from this? Since these mood-regulating neurotransmitters are found in the gut, researchers concluded that there must be a biological connection between the gut and brain. Ultimately, researchers discovered a connection between the enteric nervous system, found in the gut, and the central nervous system, present in the brain. These two nervous systems are connected by the vagus nerve, a main nerve of humans’ parasympathetic nervous system. Thus, the vagus nerve is responsible for the GUT-BRAIN AXIS: the constant communication between the enteric nervous system and the central nervous system.


Through researchers’ in-depth study of the gut, it was found that there are more mood-related neurotransmitters in the gut than just precursors to serotonin; both dopamine and Gamma aminobutyric acid (GABA) are stored in the gut. Dopamine and GABA both largely impact human emotion, anxiety, happiness, and mood regulation!


Ultimately, the bidirectional communication between our gut and brain is extremely useful to understanding how our gut regulates the production of neurotransmitters and body functions. 


Critical to the gut-brain axis is the acknowledgment that the gut, also known as the gastrointestinal (GI) tract, is responsible for digestion. Since the gut is connected to the brain, we can learn how stress negatively affects our gut. Stress and depression inhibits the vagus nerve, thereby altering the gut-brain connection. Ultimately, this weakens the gut’s function, leading to increased motility, slower digestion, and can also cause the gut to favor the growth of harmful bacterias. 


The gut microbiome, home to a collection of microbes like bacteria, is just one of the many factors that can influence the gut-brain axis. Mental distress reshapes the gut bacteria’s composition, in turn, causing the gut bacteria to release these harmful toxins and neurohormones that impact overall human functioning. So, how can we improve our gut-brain axis?


Reports show that the following practices help support optimal gut-brain function:

  • Progressive muscle relaxation
    • Progressive muscle relaxation (PMR) is a relaxation technique that involves tensing and then relaxing muscle groups in a systematic and progressive manner.
  • Restful music
  • Cognitive behavioral therapy (CBT)
  • Eating fermented foods


We once thought the GI tract was a single organ that solely functioned to support digestion. Now, we know that present in the gut are neurochemicals that impact human food and functioning. Ultimately, we’ve learned that the vagus nerve serves to connect the enteric nervous system and central nervous system. We also now know how mental distress impacts our gut and GI tract, and how to aid optimal functioning- I suggest working on these research-proven techniques to support your gut-brain axis.

More than 50% of Americans struggle with mental health.

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