The gut & brain are connected via the vagus nerve, enteric nervous system, and gut-brain axis.

  • The vagus nerve, part of the central nervous system, runs from the brain stem to part of the colon. It helps regulate heart rate, speech, sweating, and various gastrointestinal functions.
  • The enteric nervous system, the ‘brain in your gut’, is embedded in the lining of the gastrointestinal system beginning in the esophagus and extending down to the anus. The enteric nervous system consists of a mesh-like system of neurons that governs the function of the gastrointestinal tract.
  • The gut-brain axis consists of bidirectional communication between the central nervous system via the vagus nerve and the enteric nervous system, linking emotional and cognitive centers of the brain with gastrointestinal functions of the gut.

Growing Evidence Suggests a Direct Relationship Between Gut and Brain Health

 Following are excerpts from recently published scientific articles as examples of the growing body of evidence suggesting a connection between gut and brain health.

The Gut Brain Connection: How Gut Health Affects Mental Health,

Current thinking in the field of neuropsychology and the study of mental health problems includes strong speculation that bipolar disorder, schizophrenia, and other psychological or neurological problems may also be associated with alterations in the microbiome. Researchers speculate that any disruption to the normal, healthful balance of bacteria in the microbiome can cause the immune system to overreact and contribute to inflammation of the GI tract, in turn leading to the development of symptoms of disease that occur not only throughout your body, but also in your brain.

Gut Bacteria Can Influence Your Mood, Thoughts, and Brain,

Studies show that gut bacteria are related to various states of mental health. The human gut is lined with more than 100 million nerve cells, more than in the spinal cord or in the peripheral nervous system. Yes, we have brain cells in our large intestines!  What has become evident is that patients with psychiatric disorders have different populations of gut microbes compared to microbes in healthy individuals. Also, stress and stress hormones such as cortisol can have a negative impact on our microbiome.

Surprising Link Between Depression, Anxiety, and Gut Health,

Research has shown the gut microbiota influences brain chemistry and behavior. For example, people who suffer from irritable bowel syndrome (IBS) and the associated cramping, abdominal pain, bloating, gas, diarrhea, and constipation, commonly suffer from depression and anxiety as well.

IBD may disrupt mental health by breaking gut-brain link,

Around 30% of patients with inflammatory bowel disease (IBD) experience depression, anxiety, or both. A new study in mice suggests that impaired communication between the gut and the brain may be partly responsible. The study found that a gateway between the bloodstream and cerebrospinal fluid may close to protect the brain from inflammation during flare-ups. This may disrupt the gut-brain axis, a communication channel between the gut and brain with possible links to mental health.

(Carloni, S., Bertocchit, A., Mancinelli, S. et al..( 2021). Identification of a choroid plexus vascular barrier closing during intestinal inflammation. Science, 374 (6566)

Campbell-McBride, N. (2020). Gut and Physiology Syndrome. Medinform Publishing.

Our gut has been called ‘the second brain’. Some researchers even call it ‘the first brain’ because of the complexity of its nervous system, production of hormones, neurotransmitters and many other active substances. Recent research in microbiome has discovered that our gut flora is a major part of that ‘brain’. Through producing various active substances, our gut microbes can dictate our behavior and mood, and even our thoughts! Many of our desires, food preferences and mood changes are not our own; they are imposed upon us by the microbes in our gut… Every food addiction you have is likely to be imposed on you by your gut flora; the microbes in your gut are addicted to that particular food and are demanding it by giving you an irresistible urge to eat it*. This is particularly the case in people with obesity, diabetes, autoimmunity and mental illness, and the typical addictions are to processed carbohydrates (sugar, chocolate, bread, pasta, snacks, etc.).

*Alcock J, Maley CC, Aktipis CA. Is eating behavior manipulated by the gastrointestinal microbiota? Evolutionary pressures and potential mechanisms. Bioessays. 2014 Oct;36(10):940–9.

In Conclusion

Growing evidence suggests the health of the gut and the brain are symbiotic in nature. In other words, their relationship is interdependent; a healthy gut supports improved cognitive, emotional functioning of the brain and a healthy brain supports improved gastrointestinal functioning of the gut.

When suffering from distress, disorder, or disease the gut-brain relationship is out of balance.

Focusing on the ‘gut side’, a fundamental principle underlying the GAPS nutritional protocol is to help bring the gut-brain relationship into balance. The GAPS Nutritional Protocol is designed to reduce inflammation, support the gut lining, and restore a thriving microbial (gut flora) ecosystem within the digestive tract through dietary intervention and detoxification.

Your gut is your second brain – remember to trust your gut when it comes to restored health & well-being!