moody microbes: how your gut bacteria impact mental health
The gut-brain connection is real; it seems to be common knowledge at this point.
While this research is still fairly new, we do understand that there are several ways in which your gut microbiome (the community of bacteria, fungi, viruses and parasites in your gut) impact your mood and mental wellness.
This is something that really hits close to home for me - as someone who had struggled most of my life with anxiety and depression, as well as gut issues.
I had tried counselling, medication, meditation…it all helped, but I still didn’t feel myself, and I started to develop intense mood swings before my period, which I suspected was PMDD.
We are so quick to label mental health disorders without fully understanding what’s going on the body.
This is because medicine has traditionally always viewed the mind and body as separate, but modern research has disproven this - in fact, everything in the body, including the mind, is connected.
The purpose of diagnosing mental health disorders is so that doctors such as psychiatrists know which medications or which counselling therapies may work best for that person.
However, oftentimes physical or lifestyle contributors to that person’s mental health condition are overlooked.
This is because the old paradigm of mental illness was that of, “We’re not sure why, but you have a brain chemical imbalance. We’re going to give you this drug that should help, but if it doesn’t, we can try a different one.”
I’m not anti-medication at all, drugs do have their place, and for some people (including myself) they can be quite helpful, but for others that are “treatment resistant” or don’t want to take medications, we need to dig deeper and find out what’s actually going on in the body.
The top physical causes of mental health concerns:
(interestingly, all of them are connected to gut health in some way!)
Imbalanced blood sugar
Gut bacteria imbalances (dysbiosis)
Poor sleep
Hormone imbalances
Nutrient deficiencies
Adrenal fatigue (aka burnout)
Genetics
As someone who has worked with hundreds of clients, most of which have some degree of mental health concerns, there is usually more than one factor involved, however, for the purpose of this blog, we are going to focus on the role of the gut microbiome.
What do our gut bacteria do for us?
Our gut bacteria do so much for us!
They help make vitamins, optimize digestion and absorption and regulate blood sugar, immune function and inflammation. This is important to understand, because when there’s a disturbance to the gut microbiome such as poor diet or an antibiotic, this has a massive impact on the body’s ability to function.
Some of the main “happy hormones”, which are called neurotransmitters are made in the gut, but also in the brain.
These include:
serotonin: important for mood regulation (deficiencies seen in anxiety and depression, chronic pain)
dopamine: important in learning, motivation and reward (deficiencies seen in ADD, ADHD and binge eating disorder)
GABA: important for calming the nervous system (deficiencies seen in anxiety and those with alcohol abuse)
We’ll dive into how the gut impacts each of these neurotransmitters below.
Gut bacteria produce vitamins
Your gut bacteria produce many compounds and nutrients including B vitamins and vitamin K.
B vitamins are critical for building happy brain chemicals, however, people with gut bacteria imbalances and absorption issues may quickly become deficient in B vitamins, especially people with SIBO (small intestine bacterial overgrowth). This is because certain bacteria can steal your vitamins and minerals for their own use. Many people with chronic gut issues are also low in stomach acid, enzyme and bile, which prevents them from optimally absorbing vitamins from their food.
Gut bacteria produce brain chemicalS and building blocks
Your gut bacteria produce a number of brain chemicals and brain chemical building blocks. The make them from amino acids (from protein foods) and vitamins & minerals (such as B vitamins, magnesium and zinc).
They use tryptophan to produce serotonin in the gut, however, serotonin is typically too big to cross the blood-brain barrier, so most of this serotonin stays in the gut and acts locally in the gut for motility purposes, unless you have leaky brain.
Gut bacteria also produce 5-HTP which is one of the building blocks of serotonin - this is a small enough molecule to pass through the blood-brain barrier and impact levels of serotonin in the brain.
There are several interconnected hormone pathways in the gut and brain:
5-HTP > serotonin > melatonin
serotonin > levels of dopamine and GABA
Gut bacteria use tyrosine to synthesize dopamine: about 50% of your dopamine levels are made in the gut and 50% in the brain.
They also produce melatonin, which is needed for sleep, but also acts in the gut to regulate the function of sphincters such as the LES (lower esophageal sphincter), which is critical for people with heartburn or GERD (gastroesophageal reflux disease).
Gut bacteria regulate inflammation
Your gut bacteria interact with your immune system, which lies just outside your intestinal lumen (the inner part where you poop sits!). When triggered by an infection or foreign object, your immune system kicks into high gear to fight and protect you, however, if it’s trying to fight a bacterial imbalance, this can results in long term, chronic inflammation. Immune signalling chemicals include cytokines such as IL and TNF-a which are very inflammatory. It also includes histamine that is released from mast cells. Both cytokines and histamine have been proven to cause inflammation in the brain which can impact mental health. In fact, one of the newest theories of depression is that it’s caused by chronic brain inflammation.
Gut bacteria signal the nervous system
The nervous system is a sentinal - it’s always on guard to tell us when we’re in danger, or when we’re safe.
When we’re in danger it floods the body with certain chemicals such as cortisol and adrenaline, so we can run from danger. This is the sympathetic nervous system response (aka “fight or flight”). When we feel calm and safe, we tend to release feel good hormones such as GABA and feel relaxed. This is call the parasympathetic nervous system state (aka “rest and digest”).
We used to think the nervous system was just the brain and spinal cord. We now know that part of your nervous system is in your gut - the enteric nervous system. There are actually more nerves that run from your gut to your brain than from your brain to your gut! These nerves carry signals to the brain, so that when things are off in the gut, it tells the brain things are not ok - it shifts the nervous system into fight or flight, which triggers a hormonal cascade that impacts mental health.
But stress hormones aren’t necessarily “bad”; we need stress hormones like cortisol for energy and survival. They are also anti-inflammatory. But when we are constantly pumping out cortisol and adrenaline from perceived threats, we can start to feel on edge, or develop anxiety.
Long term, this can cause shifts in hormone processes in the body which can worsen anxiety or lead to depression. That’s because the body always prioritizes stress hormones over anything else - sex hormones or happy hormones like serotonin, dopamine or GABA.
Eventually, if a person progresses to late stage adrenal fatigue, their cortisol levels become depleted, and they become more likely to be inflamed and experience mental health concerns such as depression.
This is why I’m so passionate about educating my clients about the role of their adrenals in their gut and mental health. We have to learn to reject our societal standards of wearing stress and fatigue as a badge of honour, and learn to slow down and carve time to listen to our body when it asks for rest.
So what do you do if you suspect your gut bacteria are contributing to your mental health concerns?
Book an appointment with me - I created personalized gut healing plans that allow you to feel yourself again!
Book your free Meet & Greet here.
