Gut-Brain Connection (Part 1)

THE GUT-BRAIN CONNECTION reaffirms the Naturopathic Tenet……”All disease begins in the gut” – Hippocrates. 


Currently the Australian Bureau of Statistics demonstrate 1 in 2 Australians suffer a mental health issue in their lifetime and 1,000,000 Australians live with low mood each year. 

According to The Gut Foundation at least 1 in 2 Australian’s report digestive issues over a year.  The rates of digestive disorders such as IBS, IBD and GIT cancers are also increasing.  


Traditionally recognised risk factors for mental health issues have included:

  • Stress or traumatic events
  • Family history
  • Personality traits
  • Serious and/or chronic physical illness
  • Substance use and abuse

Poor diet and poor digestive health have now been identified as risk factors for poor mental health. 


The gastro-intestinal (GI) system has been called the second brain with the largest nervous system outside the brain.  However, it could not perform its job without the constant communication and actions of the single layer of intelligent cells that line the gut.  In the intestine the internal lining of the gut is one cell thick with a thin layer of connective tissue below it.  This single layer performs a remarkable amount of critical functions including very elaborate communication with friendly microbes, as well as immune cells.   


There is a functional communication between the gastro-intestinal (GI) system and central nervous system (CNS).  This is a two way communication which involves the vagus nerve (involved with the actions of the heart, lungs and digestive tract), the immune system and the hypothalamus-pituitary-adrenal (HPA) axis (our central stress response system).  In addition, there is increasing evidence suggesting another key player in this interaction: the intestinal microbiota.  This has led to the proposal of what is now recognized as the microbiota-gut-brain connection/axis.  Research now suggests that any interference in this connection/axis could be an underlying cause of a variety of functional bowel disorders including irritable bowel syndrome (IBS).

The brain may influence microbiota composition indirectly through changes in gastrointestinal motility, secretion, and intestinal permeability; or directly, via substances secreted by certain nerves and immune cells.  Intestinal motility is considered one of the most important control systems of the intestinal microbiota, by controlling its removal.  On the other hand, intestinal microbiota also play a role in network signals involving gut function, particularly when there are changes in intestinal permeability.

Integral to these communications are cells which produce gastric acid via the release of histamine.  Histamine has a local immune response.  It also communicates important messages from your digestive system to your brain.  There is some suggestion that the interaction between the gut microbiota and these cells may play a role in the regulation of intestinal pain.   The correct mechanisms of the action of this currently remain unclear. 

The Effects of Stress

Stress induces alterations in motility, secretion, intestinal sensitivity, intestinal permeability and local inflammatory responses in the gastrointestinal (GI) tract.  Stress appears to be involved in the initiation and relapse of experimental colitis.

There are a type of white blood cells in the intestinal mucosa which act as master regulators of the gut-brain connection/axis.  These cells are involved in inflammatory and allergic reactions within the connective tissue of the intestinal tract.  Hence, when under stress conditions, there may be further disruption to the intestinal barrier increasing permeability and subsequent stimulation of the immune system. 

Stress has a complex way of activating pathways which ultimately inhibit immune cell functions and promote intestinal inflammation. 

Heart rate variability, a non-invasive test commonly used to assess the nervous system which controls heart, lung and digestive function confirms the link between the central nervous system and human GI disorders.   


Do you feel like something may be out of order in your gut &/or your brain??

Contact us today for an appointment with one of our dedicated Naturopaths.




 Watch out for our next blog for further information…

Disclaimer:  The advice on this website is of a general nature only and Nurtura Health expressly disclaims all liability arising out of the improper use of the information provided.  Nurtura Health actively discourages any self-diagnosis or self-medication.  Please consult your health practitioner regarding these important health issues.  All rights reserved.