The importance of gut health isn’t just about athletic performance but also how it affects the way our brain works. After all, the brain is the master commander and its relationship with the gut is pretty intimate.
Let’s find out what the Gut-Brain Axis is first, as it’s not something we hear about very often.
The enteric nervous system (part of the gastrointestinal tract) communicates with the brain through the Vagus Nerve—the longest cranial nerve responsible for crucial functions like communicating sensory impulses to all the organs. These sensory impulses are also known as Action Potentials, so that feeling you get in your gut is real and not just in your head!
Bottom line—when you’re stressed your digestion suffers. This stress can come in many forms from physical and psychological to physiological. For example, people suffering from Irritable Bowel Syndrome (IBS) have a reduced vagal tone, which also affects their brains.
Gut microbiota, also known as gut flora, is the collective term for the microorganisms that live in our digestive tracts. It plays a fundamental role in human biology and affects everything including the process of metabolism, and endocrine, neuronal and immune function. This microbiota can produce some of the same neurotransmitters (chemical messengers) as the brain such as serotonin, dopamine, noradrenaline and GABA (helps control fear and anxiety).
Now onto the HPA Axis—sounds serious!
The Hypothalamus-Pituitary-Adrenal Axis (HPA Axis) is a core regulator of the stress response in our bodies. When we are stressed, we are likely to make poor food choices and reach for sugary drinks and refined or processed food like biscuits and chips. This increases the risk of intestinal permeability or leaky gut. As a result, poor or unbalanced gut microbiota (microbial dysbiosis) can have a negative impact on brain function as it deregulates the HPA axis.
Many athletes, as well as the general population, go through stressful periods of training and competing, which can be accompanied by anxiety or depression, particularly when their performance is at stake. Since our gut microbiota is capable of producing neurotransmitters such as serotonin, which helps with regulating mood and feelings of joy and happiness, it can be helpful with a person’s (or athlete’s) feeling of wellbeing. Changes in an athlete’s mood and gastrointestinal function could be reflection on an underlying interaction between gut microbiota the gut-brain axis especially during intense physical stress.
How to enhance the gut-brain connection
Now that we’ve covered the science behind the connection, let’s talk about how to enhance this process. I always tell the athletes I train to find out what the source of the problem is rather than focusing solely on the symptoms. If you feel that your system is stressed, find out why. Could it be a lack of sleep or too much screen time during the day? Or could it be eating too much processed food or even not having enough recovery time from training? It’s important to remember that the brain affects the gut and vice versa, and a solution can be found once the source of the problem has been identified.
Supplementing your wholesome meals with pre- and probiotics is a good way to restore healthy gut microbiota. I recommend rotating between trusted brands to reap the benefits of wider spectrums.
Include the following into your diet:
Omega-3s – contains DHA and EPA, and has anti-inflammatory can cognitive function benefits. To improve brain health, make sure the DHA content is higher, whereas to reduce systemic inflammation, EPA levels should be higher. It’s a good idea to rotate between trusted brands for Omega-3s too and make sure it’s derived from wild caught cold-water fish. You also want to make sure you’re getting enough Omega-3s on a plant-based diet.
Fermented foods – consume kefir, sauerkraut, kombucha, kimchi and tempeh, which augment the good bacteria in our intestines.
Fibre – an incredibly important addition to our diet and although we can’t digest it, gut bacteria ferments it producing short-chain fatty acids like acetate, propionate and butyrate, which are energy sources for the liver and muscle cells. Nuts, flaxseeds, chia seeds, fruits, root and dark leafy green vegetables contain soluble and insoluble fibre.
Polyphenols – these phytochemicals increase healthy gut bacteria and are also a good source of antioxidants. Can be found in olive oil, green tea, cocoa, coffee and turmeric.
Tryptophan – an essential amino acid, which is converted to serotonin in the gut. Food rich in tryptophan includes red meat, eggs, turkey, fish, oats, spinach, bananas and pumpkin seeds.
If I were to list down all the lifestyle and nutritional changes needed for optimal gut-brain-axis, it would be too long. But, a good place to start is to follow the simple advice in this article and see how much better you will actually feel.