Gut Brain Connection

How gut health affects mental health

The connection between your gut and your brain is real.  So if you are suffering from Anxiety, Depression, Brain Fog, Fatigue or insomnia consider looking at your gut health. 

Digestive issues can affect your mood and impact your mental health, in some cases severely.  There are a lot of conditions which are labeled “Mental Health” problems that are resolved when we start treating the cause of origin i.e. the gut.

So if you are suffering from mental health issues and you have a gut disorder, it is really worthwhile investigating and trying to resolve them to see how this improves your mental health.

Vagus Nerve

The Vagus Nerve is the connection between our gut and our brain.  It runs from our brain right down through our body, to the bladder. For many years we have considered the brain to be the most superior organ inside the body.  However, in the last 10 years there has been an explosion of research that has shown us how critically important the gut is to human health.  That the gut is connected to so many parts of the way that we work as human beings.  We can debate “Is the gut more important” or “Is the brain more important”.  That debate is not necessary because they are working together.  They are intimate friends and literally communicate with each other.

The VN is sensitve to short change fatty acids which are produced by the microbiome, so in essence, your gut is telling your brain how to function.

This communication pattern, the way that they can influence each other and we call this the gut brain axis.  This is so important because the reality is that when you affect the gut, you will affect the brain and vice versa.  You cannot separate the two.  So if we want brain health, then the way we start brain health is by taking care of our gut and optimizing that.

The Gut and the Brain are both autonomous systems, they work on their own but they are intimately connected and have a huge influence on one another.  

The Gut and the Brain are connected in a number of ways.  

  1. Through the neurological system.  The Gut is lined with the enteric nervous system (ENS) , a dense set of nerve endings that line the entire digestive tract – all the way from the mouth to the bottom.  The ENS has more nerve endings than your spinal cord, a very elaborate neurological system.  This system is connected to the brain via the Vagus Nerve which connects the ENS to the brain directly.
  2. Through the immunological system.  There is a lymphatic system that is present in your brain that was recently discovered.  The Brain has its own Lymphatic circulation and the immune system has a huge influence on the brain, both inflammatory and anti-inflammatory.  So things that happen in your gut where around 70-80% of your immune system exists, has a direct impact on the immunological response in the brain.
  3. Through the normal circulatory system – the blood. There are things such as neurotransmitters and small molecules that are made in your gut and directly absorbed into the circulatory system through the gut lining that can end up in your brain.

So your gut can be the biggest supporter of your brain or become the most toxic thing for your brain over time.

Seratonin – Dopamine – GABA are just three of the many
neurotransmitters synthesized by the microbiome

There are over 30 neurotransmitters that are produced in the gut.  90-95% of serotonin the “Happy Hormone” which affects our mood, focus, energy levels – is produced in the gut.  Around 50% of Dopamine is produced in the gut.

The bottom line, your gut is producing neurotransmitters every minute of every day.  They can affect your mood, focus, energy levels and brain health.  You cannot separate your brain from your gut.

When we suffer a damaged gut then we should expect to see consequences in the brain.  It is surmised that there are links between a leaky gut or dysbiosis with Anxiety, depression, PTSD, autism, parkinson’s disease, alzheimer’s disease.

Stress and the Gut

Stress of any kind releases cortisol, a natural steroid, and this can create havoc with the bacteria in the gut. Stress will reduce poliferation of the gut microbiome and reducing our capacity to digest food with the knock on effect of causing food reactivity and sensitivity. Cortistol and Adrenaline are stress hormones that run through our system and cause overgrowth of undesirable bacteria.

Quiet your mind – reduce your stress
This will have a positive impact on your microbiome

The roll of the microbiome.

Your brain produces neurotransmitters which communicate with your microbiome.  The Microbiome also produces neurotransmitters involving gamma, dopamine and serotonin production.  So you can see how an unhealthy gut can affect your mood.

What are the risks of gut health deterioration?

Dysbiosis is another way of describing an imbalance in the microbiome leading to health and disease issues. A loss of balance within the gut microbes – less diversity or overpopulation of certain species over others. When this happens – it infects the lining of the gut.

Fundamental problems include:

  1. Lack of diversity.  We need thousands of different species of organisms.  We should have between 3-4 hundred different species of bacteria.  Tests of the average westerner have shown only 115-120 species compared to the diversity of the hunter gathers.  Hadsa tribes in Tanzania, tribes in Papuya New Guinea the people live like our ancestors.  They have 2-3 times more bacterial diversity.  We are suffering from a mass extinction of critical microbes that perform critical functionality.
  2. Significant loss in critical micro-organisms called “Keystone Strains”.  KS are really important species that not only support the rest of the ecosystem but also directly impact the disease process.  Akkermansia Muciniphila is a very well known and studied strain.  It protects everything that comes under the cardio metabolic syndrome which contains 60 different diseases e.g. diabetes, obesity, heart disease, certain types of cancers and emotional issues such as anxiety and depression.  AM this one organism in the gut, protects against all of those different dysfunctions. Faecalibacterium prausnitzii another keystone strain protects against all kinds of inflammatory conditions of the bowel.
  3. Leaky gut.  This creates huge problems in the barrier structure of the intestinal lining is the ground zero for most health disorders.  You can trace back the vast majority of illnesses to some dysfunction of the barrier structure in the gut.  This is now being acknowledged by research projects by the National Institution of Health.
Cognition and Memory

The microbiome plays a huge role in cognitive diseases which have increased rapidly over the last 10 years. The microbiome has the potential to process macro / micro nutrients that we ingest and convert them into neuro active compounds. These compounds cross the blood brain barrier and impact our cognitive functions.

Studies have found that when looking at Parkinsons disease patients, the vagus nerve is enriched with Lipopolysaccharides with constipation being one of the first symptoms for a patient, because the Vagus Nerve plays a significant role in motility in the gut.

The Enteric Nervous System surrounds the bowel and all of our neuro transmitters are manufactured in the bowel, so the bacteria are essential for producing neurotransmitters for our brain to function well.


When we get constipation, we have waste products sitting in the bowel and as a result, the bacteria start to break down this waste, recycling toxins back into the system. It is not normal to be constipated and this is a piece of the puzzle when it comes to neuro degeneration. Of course it’s true that not everyone with constipation has Alzheimer’s disease, but the process of inflammation affecting the brain is all too clear. Constipation can cause brain fog, irritability and trouble sleeping. It has been found that by addressing this one symptom, it changes people’s mood and reduces anxiety and more importantly it is removing waste from the body.

Improving Neuro Inflammation

There is some evidence that Parkinson’s Disease can start 20 years before symptons appear so it is never too late to make changes to improve and reduce neuro inflammation. By improving your diet and lifestyle thereby, rebalancing your microbiome, reducing inflammation of the gut and consequently the brain, we can improve our future outcomes in terms of Parkinson’s Disease, Dementia and Alzheimer’s.

Addressing dysbiosis, healing leaky gut and rebalancing our microbiome, we can potentially reduce and even eliminate a lot of mental health problems.