Why is it that you feel butterflies or knots in your stomach when you’re nervous?
Or have you ever heard that you should follow your gut instinct?
These expressions aren’t just something that you learn from your nan, they signal an innate understanding that our brain & gut are intimately linked.
After last month, I felt like I couldn’t do the topic Heal Thy Mental Health justice without discussing the Gut-Brain connection.
So how is it that our guts and brains talk to each other? They have a bi-directional relationship via our nervous system, hormones, our microbiome, neurotransmitters & our immune system.
This relationship is cyclical in nature. The state of our gut can affect the brain and the state of our brain can affect the gut.
How does the brain affects our gut?
Our brain sends messages through our nervous system, which help to connect our Central Nervous System (CNS- this includes about brain and spinal cord) to our Enteric Nervous System (ENS- which governs our gut).
Our autonomic nervous system (ANS) basically controls anything that is regulated automatically such as breathing, heart rate, digestive secretions and immune function etc. The ANS is further divided in to the Sympathetic and Parasympathetic Nervous systems. Our vagal nerve represents the main component of the parasympathetic NS and brings information from our gut, liver, heart and lungs to the brain and vice versa.
You can think of the Sympathetic NS as our “fight or flight” response and the Parasympathetic NS as our “rest and digest” state.
Now, which one do you think we should be activating most for optimal digestion?
Constant activation of the sympathetic NS decreases blood flow to our gut, reduces digestive secretions, gut motility, increase intestinal permeability & even disrupts our microbiome.
When we perceive stressors in our environment (physical, mental, emotional etc.) this messaged is relayed to our brain, which then send out signals from the Hypothalamus to the pituitary, which then triggers the release of cortisol from our adrenal glands.
Known as our Hypothalamic-Pituitary-Adrenal axis (HPA axis), it also plays an integral role stress response and contributes to the activation of either the Sympathetic or Parasympathetic NS.
In this state you’re more prone to reflux, Leaky gut, immune issues, dysbiosis, irritable Bowel Syndrome (IBS), Irritable Bowel Disease) IBD, food allergies and intolerances etc.
In a vicious cycle, it’s these conditions and poor gut function that can create havoc in our brain!
How our does our gut affect our brain?
Your gut is doing a lot of heavy lifting when it comes to optimal brain function.
Our microbiome is a key player, what can’t those cheeky little bugs do?
Not only do they protect our intestinal barrier from foreign invaders, but they break down carbohydrates from our food to produce short-chain fatty acids (SCFAs) which are fuel for our intestinal cells. This prevents the entry of any toxins, food, pathogenic bacteria from crossing our intestinal barrier. If they were to cross over, they can activate our immune system & trigger create an inflammatory reaction which Can cross our Blood-Brain Barrier (BBB) and create a leaky and inflamed brain.
Our intestinal barrier also house special cells where the majority of serotonin is created in our body. Not only does serotonin help regulate our mood and sleep but also controls our appetite & gut motility. So quite often mental health conditions such as depression and anxiety can be correlated with episodes of constipation or diarrhoea.
They also help with the production of GABA and amino acid metabolism (those important building blocks we need to make happy, calming & motivating brain chemicals).
Our bugs also help to make brain-derived neurotropic factor (BDNF) which influences cognition and brain plasticity (how our brain creates new connections- VERY important when it comes to cognition dysfunction, memory and mood regulation!)
You can see that there’s more than the few ways the gut and our brain are dependent on each other to function optimally.
From mood, to cognition, eating habits, anxiety, depression and changes in your bowel habits it’s often a combined result of a dysregulation in these two systems.
As always, if you are experiencing any of the gut symptoms we mentioned or want to seek additional support for a mental health condition please consult your health practitioner or reach out if you have any questions after reading this months blog! We are all so different when it comes to the causes of any health condition, so it is vital that you discover yours with the help of a professional.
Until next time,
Love Rom & Al