As research continues to explain the link between the gut and mind, the science behind what we eat is revealing the symbiosis between gut health and mental health.
In an unexpected turn of events, it seems you might be able to eat yourself happy — unfortunately this doesn’t include chocolate, ice cream or any other indulgent items you might reach for in times of stress or sadness.
Recent research suggests that gut health is closely tied to both mood and mental health, and the state of our gut depends heavily on what we put into our mouths.
What is the gut?
The GI tract (gut) is the entire digestive system, from entrance to exit, but typically it refers to the large intestine, as this is where the majority of the body’s bacteria (microbiome) exist and two important hormones are formed.
Shann Jones, founder and director of Chuckling Goat, which produces a kefir from fermented goat’s milk that’s beneficial to gut health, tells me: “I like to imagine it like the Amazon rainforest,” she says. “With birds, bugs, lizards, leaves, trees and jaguars all running around in this complex natural ecosystem. And, like any other, the gut is fragile, and it can be damaged. So feed it, love it, and don’t poison it.”
Physical connections between the gut and your mood
Just 2% of gut cells — found in the wall of the large intestine — actively influence other forms of health. These enterochromaffin (EC) cells produce 90% of the body’s serotonin and 50% of its dopamine. Both are neurotransmitters that pass chemical messages throughout the body and are vital to creating feelings of happiness and satisfaction.
Often referred to as the ‘happy hormone’, serotonin creates the experience of happiness and excitement, while dopamine is important for feelings of reward and motivation. Low levels mean low motivation for almost anything in life, because you’re not feeling benefits or joy from achievements.
Both hormones are important to the body in a multitude of ways, from your bones to your heart, and this is why gut health can lead to a health issues like autoimmune conditions (when your immune system attacks your body); examples include type 1 diabetes, psoriasis and multiple sclerosis. Another example of the gut’s link with physical health is that inflammation in the gut can lead to inflammation in other parts of the body, and so restoring gut health can hugely impact chronic pain throughout the body, for example that experienced by arthritis sufferers.
Read more: The gut-skin-axis: how poor gut health can trigger acne and other skin conditions
How gut health contributes to good mental health
Once you know the amount of these vital mood hormones that are produced in the gut, it’s easy to understand how an unhealthy tract might be detrimental to your wellbeing, but it doesn’t stop there, and it isn’t comprehensively understood.
In February this year, researchers in Belgium published one of the first studies on the subject involving humans. They found participants who were diagnosed with depression or low quality of life also had low levels coprococcus and dialister. How these two gut microbiomes interact with the brain remains unclear, but Dr Orli Rhodes Kendler, at MyHealthcare Clinic, is able to some light on how it’s all connected.
“There are more than 100 million nerve cells lining the gut. These cells communicate directly with our brain — we call it the gut-brain axis, and there’s a direct feedback mechanism between the two. What we feel or think has a direct effect on how our GI tract functions, and any irritation in the gut sends signals to our brain, changing our mood.
“We use the expression ‘gut feeling’, as the GI tract is sensitive to emotions like anger, sadness, anxiety and stress — all of these emotions will have a direct effect on the gut through nerve connections that we have from our brain. Some people will even experience functional disorders such as pain, diarrhoea or constipation.”
How to have a healthy gut
Sugar, stress, environmental toxins and antibiotics are what Shann refers to as “the four horsemen of the gut apocalypse”, with antibiotics seemingly the worse culprit. “It’s like pouring bleach into a river,” she explains, continuing with the Amazon metaphor. “It doesn’t just target the infection; it kills all the fish and everything else, and the bad bacteria will be the first to return.”
Considering that these four things are difficult to avoid — stress is part of life and antibiotics are often the only option to combat infections — the outlook starts to look pretty bleak, but Shann assures me it can all be restored with the live bacteria found in fermented foods.
“The fastest and easiest thing you can do is drink unflavoured and unsweetened kefir that isn’t made from cow’s milk, as that can irritate the gut. It has a multiplicity of strains, mirroring the number in your gut, making it is more powerful than other probiotics because they will only have a few strains. Kefir puts the fish in the river, but you have to feed those fish well, and then the diverse microbiome can protect itself.”
Shann’s company is currently assisting with medical research into the link between mood disorder and kefir at Aberystwyth University. Using live bacteria used medicinally in this way are known as psychobiotics, and scientists believe they’ll lead to an entirely new form of medicine. So far, Shann tells me, results have shown people start to feel calm and happy quite fast, but when it comes to physical health, the benefits are slow to show.
Leaving me with another metaphor, Shann explains that medicine is like being given an apple, but fixing gut health is like being given a seed — you have to wait for it to grow and then you’ll have an abundance of fruit.
“This is not a mindset that’s popular in the modern world,” Shann laments. But tells me again that all we need to do for gut health is to try to “feed it, love it, and not poison it”.