Early research shows the connection between the gut brain axis and mental health.
Did you know that over 25% of Australian adults report high levels of anxiety or depression?
In fact, for antidepressant prescriptions per capita, Australia has the second highest rate in the world which is shockingly increasing by around 25% each year.
As a result, the gut-brain axis and mental health is fast becoming a hot area for research to decipher if your microbiome could influence your mood or trigger anxiety, and vice versa. (1)
How Your Gut Affects Mental Health
Your gut and brain are so intimately connected that they communicate in a number of different ways.
Here are three ways that your gut health can influence your mental health.
- Gut inflammation can trigger the stress response system: Leading to feelings of heightened anxiety and low mood.
- Imbalance of bacteria: Bacterial species such as proteobacteria has been shown shown to make neurochemicals that are identical to stress hormones.
- Migration of bacterial toxins to the brain: Bacterial toxins called lipopolysaccharides (LPS) is a toxin produced by bacterial species such as proteobacteria, that when transferred from the gut into the blood stream can enter the brain creating inflammation and worsening mood.
Low Microbial Diversity and Depression
Having a low abundance of beneficial bacteria in your digestive system, could increase your risk of depression.
In a 2019 review of human studies on the gut microbiota and mood disorders, it was shown that those experiencing a depressive like state had a lower amount of bacteria that produce short chain fatty acids.
That’s because 90% of your serotonin (your happy neurotransmitter) is produced in your gut. One of the pathways that stimulates the production of this happy hormone, is through the metabolite called short chain fatty acids. (2)
Short chain fatty acids are produced when certain bacterial species in your gut break down fibre. This is why eating a variety of plant based foods are so important for healthy gut bacteria and mood.
A microbiome that has an abundance of short chain fatty acid producing bacteria are associated with a higher microbial diversity (abundance of good bacteria) and a healthier digestive system.
If you are curious on how many good or bad bugs you have in your digestive system, a microbiome analysis will help you uncover just that. Learn what microbiome testing is and how it can help you.
Gut Health and Anxiety
An animal study found that rats who were fed a specific bacterial strain called L.rhamnosus for six weeks, had fewer signs of anxiety and stress. For example, the rodents spent more time exploring narrow elevated walkways and wide open spaces which are usually intimidating for rodents. (3)
The researchers found that there were changes to GABA receptors, a neurotransmitter which helps to calm the mind when in a stressed, anxious state.
Medications such as benzodiazepines directly affect this same neurotransmitter to reduce anxiety.
The findings may not directly correlate with humans, but it’s certainly an exciting start.
Gut Brain Axis & Parkinson’s Disease
Though Parkinson’s disease is not classified under ‘mental health’, it’s still interesting to hear the link between Parkinson’s disease and it’s connection to gut health.
One of the strongest risk factors for increasing the risk of Parkinson’s disease, is constipation.
80% of people suffering with Parkinson’s disease experience a history of ongoing constipation.
This suggests that Parkinson’s disease may in fact start in the gut, long before motor symptoms even begin.
The microbiome of those with Parkinson’s disease are found to have an overgrowth of bad bacteria including an abundance of Enterobacter and Prevotella, both of which are gram negative bacteria that produce lipopolysaccharide (LPS).
High amounts of LPS can increase leaky gut syndrome, gut inflammation which could then also contribute to brain inflammation.
