If you've ever felt "butterflies in your stomach" when nervous or "gone with your gut" when making a decision, you're getting signals from an unexpected source: Your second brain. Masked behind the walls of your digestive system, this "gut-brain" helps us understand our mood, health, and digestion.
The human body's stomach and brain connection is a truly remarkable feature. To learn more about this, see the comprehensive guide below:
How does the stomach and brain connection work?
The stomach and brain connection operates through the gut-brain axis (GBA), which is a bidirectional link between the enteric nervous system (ENS) and the central nervous system (CNS).
Throughout this bidirectional link, it has direct and indirect routes between emotional and cognitive centres in the brain with peripheral intestinal functions. To increase its influence on our brain, it also has complex crosstalk between the immune (cytokine and chemokines), endocrine (hypothalamic-pituitary-adrenal axis), and autonomic nervous system (ANS).
The GBA primarily combines the parasympathetic and sympathetic arms of the autonomic nervous system (ANS), driving efferent and afferent neural signals from the gut to the brain. Located in the ANS is where the nerve connecting the stomach to the brain is located. This is called the vagus nerve.
With help from the vagus nerve, it facilitates feedback from the intestinal end to the brain system. Having this enables us to engage the limbic and hypothalamus system, which is responsible for regulating emotions. For this reason, the gut can trigger happiness, stress, and anxiety, depending on its health.
When the nerve connecting the stomach to the brain is healthy, it triggers a positive response. What makes an impact on this is the gut's microbiome.