Gut-Brain Connection

The Science Behind Mind-Body

Dr. Mallory Harris, ND

We often use mottos like, “gut-wrenching, butterflies in your stomach, gut instinct, listen to your gut, gut feeling,” without thinking deeper into what they really mean.  Only recently have neuroscientists been able to reveal the science behind the connection between our gut physiology and our brain function, also known as the Gut-Brain Axis.

Gut-Brain Axis

The Gut-Brain connection explains why when we feel nervous, we get butterflies in our stomach and why when our stomach is bothering us we tend to feel irritable. This is a bi-directional relationship and research has started to uncover how it works, providing exciting clinical implications on how we should treat digestive complaints like irritable bowel syndrome (IBS) and stress, anxiety and low mood.

Our gut microbiota is the key player in controlling the gut-brain axis, creating a new term called the Microbiota-Gut-Brain Axis.  

What is the gut microbiome?

Our gut microbiome is comprised of mainly bacteria but also yeast and parasites that regulate our digestion and immunity. They first colonize with exposure to the mother’s vaginal microbiota at birth. Studies have shown that the core colonization of bacteria differs between vaginal birth and C-section babies, the latter having an impact on digestion, immunity and allergy tendencies. Microbial cells outnumber our human cells and weigh similarly to the weight of our brain. The composition of our microbiome is constantly being influenced by the food we eat, sleep patterns, antibiotic exposure and gastrointestinal distress such as travellers diarrhea.

Altered gut microbiota influence the body’s stress response, anxiety and depression-like behaviours. This is because gut microbiota communicate with the brain or central nervous system (CNS) through a few different mechanisms, the most important neural pathway being the vagus nerve, a nerve that helps regulate our parasympathetic system or “rest and digest” system.

What can you do?

In a nut shell, in order to truly address stress, anxiety and low mood you need to optimize your gut health. Similarly, to have a real impact on your digestion, IBS or bloating, you need to put the work in and invest in your mental health and learn stress management strategies.

See my blog on stress management strategies to learn how to activate your vagus nerve in order to help rest and digest.

Diet, probiotics and prebiotics (food ingredients that promote growth of good bacteria) have been shown to help modify the microbiome in order to optimize the gut and address the mind.

Food Sources of Prebiotics Include:

Comprehensive Stool Analysis

Every individual is different and has a different composition of gut microbiome. You can tailor your diet and probiotic treatment by seeing a Naturopathic Doctor and running a Comprehensive Stool Analysis which can tell your which bacteria, yeast and possibly parasites you have in your gut as well as provide markers of digestion and absorption, inflammation and immunology.