This article is going to look at the gut brain connection. This is a topic that you could write a whole book on, so unfortunately it will only be a brief summary, a good refresher!
The Enteric Nervous System
Many studies over the years have demonstrated that there is a connection between the GUT and the BRAIN. Our gut has been described by some as having “a mind of its own”; this is referring to the enteric nervous system. Just like the brain in our head, researchers say, this system sends and receives impulses, records experiences and respond to emotions. Its nerve cells are surrounded and influenced by the same neurotransmitters. This means the gut can upset the brain just as the brain can upset the gut.
The enteric nervous system is located in the sheaths of tissue lining the oesophagus, stomach, small intestine and colon. It is considered a single entity, and is made up of a network of neurons, neurotransmitters and proteins that send messages between neurons and support cells (like those found in the brain), and a complex system, which enables it to act independently, learn, remember and, produce “gut feelings”.
The enteric nervous system contains many more neurons than the spinal cord. It acts under the direction of the autonomic nervous system but is also able to operate entirely independent of the brain. It controls bowel functions including peristaltic muscle movement, mixing/churning movements, peristalsis, intestinal blood supply, enzyme secretion, and water and electrolyte exchange. It also has a complex interaction with the gut and the immune system. The gastrointestinal associated lymph tissue is the largest immune compartment in the body. T-lymphocytes in the gastrointestinal epithelial layer account for 60% of all the lymphocytes in the body. (Lymphocytes are white blood cells, which are responsible for immune responses.)
Common Major Neurotransmitters in the Gut & Brain
All of the major neurotransmitters found in the brain are also found in the gut, such as serotonin, dopamine, glutamate and norephinephrine. Other signalling molecules including nitric oxide, certain neuropeptides (small brain proteins) and enkephalins (members of the endorphins family) are also found in the gut.
Serotonin is the main neurotransmitter of the bowel. With approximately 95% of the body’s serotonin being manufactured in the gut to help control intestinal movements. Serotonin regulates our mood, appetite, sleep, and muscle contraction. It also plays a role in some cognitive functions, including in memory and learning.
Gut permeability may also play a part in the gut brain connection. An increase in gut permeability, also known as leaky gut, can allow incompletely digested food proteins (for example gluten and casein) to move into the blood stream where they are then able to cross the blood brain barrier and affect behaviour, in certain individuals. (Please note – refer to our article Leaky Gut Syndrome for more detailed information on this condition.)
The Role of Gut Flora (Bacteria)
Another vital component of our gastrointestinal tract is our gut flora. There are over 100 trillion bacteria that colonize our gut, and over 400 of these species have been identified. Some of their important roles include; breakdown of nutrients (for example short-chain fatty acids, fibre and oligo-saccharides), regulation of fats, triglycerides and cholesterol, the production and absorption of vitamins, mucous production, and detoxification. Intestinal dysbiosis is defined as a state of imbalance in the gut, this term may be used when an individual has an overgrowth of unwanted/bad bacteria in the gut.
This may lead to incomplete breakdown of foods, excessive bacterial fermentation in the gut and “autointoxication” from endotoxins (toxins produced by undesirable bacteria in the body). Gut dysbiosis may also result in an array of behavioural symptoms, along with digestive disturbances and skin rashes, among other symptoms.
Incomplete elimination of waste products from our gut will also affect the gut brain connection. Regular stooling is essential to help eliminate the normal daily by-products of the body and to allow undesirable ingested items to pass through the body unabsorbed. Regular elimination also helps rid the intestines of undesirable microbes (such as bacteria, viruses, parasites and yeast). Constipation and faecal retention are two of the main problems linked with incomplete elimination.
Constipation is difficulty in passing stools which leads to incomplete and irregular elimination of stools. It is a common problem among many people; however it occurs in greater frequency in patients with neurodevelopmental disorders and food allergies. Faecal retention is incomplete elimination of stools and a tendency to retain excessive stool in the gut. (Please refer to our newsletter on faecal retention and constipation for more detailed information on this topic.)
Conclusion, Clean the Gut First!
The above information demonstrates the importance of maintaining a healthy gut. Most biomedical practitioners will agree that cleaning up the gut is the first priority in the treatment of many conditions. If you do not clean up the gut, the rest of the healing effort will be more complicated and less effective. Jon Pangborn (PhD) and Sidney Macdonald Baker (MD) go as far to say… “be wary of any report you read about this or that treatment that has not worked in children with autism, if the researchers have failed to address gut issues first”.
Please feel free to contact us with any queries you have regarding this topic or any other topic which I have discussed over the years.