The Gut-Brain Axis

“At our recent Open Day at Kangaroo Point Naturopaths and Wellness Centre I shared some understanding of the Gut-Brain Axis with the participants, and have included the transcript of the presentation here for those who were not able to make it.”
— Cathy Vanzanden, Naturopath

One of my passions is helping people with depression and anxiety through natural medicine. There are so many options available that can help with these symptoms.  There are many contributing factors to mental health issues – including trauma, genetic factors, lifestyle, but one of the major influences that not many people are aware of is what is going on in the gut.

Has anyone ever experienced butterflies in the stomach when they are a bit nervous or excited?  What about feeling sick or having diarrhoea when feeling really stressed?  These are examples of the connection between our brain and our gut, and there is a constant 2 way communication going on between digestive system and our brains, and whatever is going on in one will affect the other. The term for this is the Gut-Brain axis.

The communication between our central nervous system and our digestive system occurs via the gut microbiome, which is the collection of gut bacteria that lives in our colon.  The way that it communicates is via the vagus nerve, which is a cranial nerve that runs from our central nervous system to all of the major organs in our torso, including the liver, gall bladder, pancreas, heart, lungs, stomach and the entire length of the digestive system.  The other major form of communication between our gut and brain is via neurotransmitters, as the gut is influenced by the same neurotransmitters as our brains, with many neurotransmitters even made in the gut.  Over 90% of our serotonin actually lives in the gut.

Our microbiome helps us absorb nutrients from our food and to make our neurotransmitters. They help our immune system to adapt to our environment and even influence our mood and mental health.  WE have 10 x more bacteria within our bodies than we do human cells.  Isn’t that extraordinary?  You could say that we are just a walking host for a massive bacteria colony.  But this is a symbiotic relationship.  Our bacteria are very important to our health and wellbeing, and we want to look after them as best as we can.

Imbalances in our gut flora can affect the way we think and how we feel, and are linked with anxiety, depression, autism, bi-polar, even difficulty concentrating or relaxing is linked to microbiome imbalances. These bacteria can even influence the type of food we crave.  So next time you’re crawling up the walls in search of sugar, you could blame a few insidious little microbes.

Who here has had a course of antibiotics in their lifetime?  Antibiotics can be lifesaving when we have a severe infection, but as a side-effect, they also kill off some of our good bacteria.  Which is why we recommend a good probiotic supplement alongside of antibiotics to help replace these good bacteria, and avoid some other microbes from taking over – such as candida.  Antibiotics can change the make-up of the gut microbiome, which can then affect our immune system, nervous system and have even been linked to obesity. Avoid the over-use of antibiotics and only use them when absolutely necessary, as their overuse and abuse is leading to antibiotic resistance.

Food is incredibly important when it comes to looking after our microbiome.  Certain foods provide good bacteria and are called probiotic foods – fermented foods such as kefir, yoghurt, kombucha and fermented vegetables.  Other foods nourish and support the growth of good bacteria which are prebiotic foods – examples include such foods as radishes, Jerusalem artichokes, leeks, asparagus, carrots, sweet potato, onions and garlic.  Lots of vegetables provide fibre to feed the good bacteria, as well as provide you with antioxidants and important phytonutrients. The other important thing is to cut sugar and refined carbohydrates, as these foods feed the sort of bacteria that you want to avoid.

While we are on the subject of our nutrients, do you know that the brain uses up 25% of the energy that we absorb from our food?  That’s an awful lot of energy requirement for an organ that is only about 1.5kg in weight.  The brain needs quality protein from our food to build structures and neurotransmitters, good fats for nerve conduction, and carbohydrates for fuel.  Not to mention all of the essential vitamins and minerals to keep everything functioning smoothly.

The connection between the gut and the brain occurs via the vagus nerve.  This nerve controls the blood flow to all of these major functions, and brain trauma or neurodegeneration may compromise this blood flow and cause leaky gut, inflammation, low stomach acid, and even constipation. The vagus nerve is like the super highway of communication between the gut and the brain.  But if there are roadworks or traffic jams, there are going to be issues with this communication. One of the things that you can do to strengthen your vagus nerve is gargling – up to 12 times per day to really get the neural firing happening. You can build up your time, starting with 15 seconds at a time, and building up to 2 minutes for a serious session.  Another fantastic way of strengthening the vagus nerve is singing, which is not only good for your vagus nerve, but also your soul.  The other thing we can offer through naturopathy is herbal bitters which stimulate the vagus nerve and support GIT function.

There are a number of issues in the GUT that are linked with mental health issues including irritable bowel syndrome, leaky gut, food sensitivities, parasites or infections, Crohn’s disease or ulcerative colitis, and the list could go on.  All gut issues will limit the absorption of nutrients and affect our overall health and wellbeing.

Has anyone here ever heard the term leaky gut?  It’s a description of damage that can occur to the inside of the bowel wall where the nutrients normally pass into the bloodstream. The bowel wall is like a fine sieve that lets the broken down nutrients into the bloodstream, but the bowel wall can be damaged, and then larger particles can make it through into the bloodstream and cause all sorts of problems. There are quite a few contributors to leaky gut, such as stress, toxins, excessive alcohol, drugs, certain inflammatory foods, or infections.  Leaky gut causes inflammation, which can cause food sensitivities, joint pain, confuse the immune system AND is linked to depression.

That leaky barrier also occurs at the blood brain barrier, which triggers inflammation in the brain, lowering the serotonin available, which is directly linked to depression.  Food sensitivities also cause things like brain fog and depression, again through inflammation in the gut, leading to inflammation in the brain. And of course, food sensitivities are one of the causes of leaky gut, which contributes to inflammation and more food sensitivities. It is interesting to note that those people who have inflammatory bowel disease, like Crohn’s disease or ulcerative colitis have twice the incidence of depression than healthy subjects.  This is directly linked to inflammation.

Then there are mental health issues that have a detrimental effect on our gut.  What do you think the biggest one is that affects so many people?   Stress….   Stress actually changes the make-up of our microbiome and affects the absorption of our nutrients.  It also affects the bowel wall and contributes to leaky gut.  It messes with our immune function, and makes us more susceptible to viruses, bacteria and parasites, which of course will continue in that vicious cycle of inflammation.  Stress is something that most of us are susceptible to in our modern lifestyles, but we need to take it a little more seriously, as it affects every system in the body.  Make sure you are scheduling in some down time, and stress relief in your busy schedule.

As Hippocrates said so many years ago, “All disease starts in the gut”, and this definitely applies in the case of mental health issues.  As natural therapists, we are focused on the big picture and how each system affects the other, which is why when you come for a consultation we ask so many questions.  We’d love to help with any health issues that you or your family are experiencing, and we are looking to uncover and treat the cause of the problem.  Thank you for attending our open day today and we hope we can give you a little bit more of an idea of how you can look after your health.

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