You’ve no doubt heard all about the importance of gut health and noted the growing trend of fermented foods and probiotics on supermarket and health food store shelves. It is commonly accepted that good gut health is intimately linked with good health and wellbeing…. but do you know of the connection between a healthy gut environment and its effect on your brain and mental health?
The digestive and nervous systems are intimately connected via hormones, neurotransmitters and the vagus nerve in what is knowns as the gut-brain axis. Through wholesome habits in our diet and lifestyle we can nourish this bi-directional connection and improve both our digestive and mental health.
So, what exactly is this gut-brain connection?
You know how when you are nervous you can feel butterflies in your stomach? Or maybe experience loose bowels?
How about when you think about or see delicious food when you’re hungry and your mouth starts to salivate? That’s the gut-brain connection! Your brain is sending signals to your gut and you experience sensations in your body.
However, the gut-brain connection is actually a bidirectional highway of information, with the gut also sending signals to the brain. We know an out of balance microbiome – known as dysbiosis – is linked with digestive symptoms such as IBS, constipation or diarrhoea, but it also plays a role in our mental health and conditions such as anxiety and depression.
How does the gut and brain communicate?
The brain and gut communicate via three divisions of the nervous system. In short, these divisions are:
The parasympathetic nervous system (PNS) aka ‘rest and digest’ mode.
The sympathetic nervous system (SNS) aka ‘fight or flight’ mode.
The enteric nervous system
We are in parasympathetic mode when we are relaxing, and our body is able to rest and digest. When we experience stress, the sympathetic nervous system is activated, and we go into ‘fight or flight’ mode. In this state our digestive system gets shut down and digestion slows.
The enteric nervous system links the brain and digestive system via the Vagus nerve which is a major player in parasympathetic control (i.e., relaxation). It is sometimes called the second brain and is an extensive nervous system in the gut that controls digestive function.
The microbes (i.e., bacteria) in our gut are also able to communicate with the brain through their production of substances such as neurotransmitters, which can travel through our system to the brain. Here they are able to affect your emotions, feelings and behaviour.
For example, serotonin, you may know as our feel-good neurotransmitter, is produced in our gut! If our gut microbiome is out of balance, we can have insufficient amounts of this chemical messenger that supports good mood.
So why is this all so important?
A healthy gut microbiome and its connection to the brain is important because it is crucial in maintaining healthy digestion and good mood. When we are eating in a sympathetic dominant state (i.e., stressed), food is not digested properly. This can lead to fermentation and our gut bacteria not being able to break down food properly, which may result in symptoms such like bloating or cramping. Additionally, if your gut bacteria are out of balance and cannot produce the substances you need for good mood, your brain can be out of balance, contributing to stress, anxiety and depression.
So how can you best support a healthy gut-brain connection?
Eat whole foods
Most important in supporting a good gut environment is eating a range of wholefoods such as fruit and vegetables, wholegrains and legumes. These provide healthy bacteria with fibre they can use as fuel to live and keep your gut populated.
Fermented foods such as sauerkraut, kimchi and tempeh will also help to increase your gut bacteria diversity.
Reduce foods that deplete or damage the gut environment
Remove or minimise substances that weaken a healthy gut environment such as sugar, alcohol, coffee or processed foods. These substances are inflammatory in our bodies and can wipe out “good” bacteria while feeding “bad” bacteria, leading to an out of balance gut.
Probiotics are live bacteria such as Lactobacilli and Bifidobacteria that can be useful in restoring an unbalanced gut microbiome and supporting healthy digestion and mood. Certain strains of probiotics have been shown to target certain conditions and if this is something you are interested in, it is best to check in with a health practitioner to find out the best strain and dosage for your specific needs.
One of the most basic, yet important ways to nurture the gut-brain connection is to eat mindfully. This means really slowing down while you eat by sitting down, taking a moment to connect with your food, the taste, its smell, the people around you and the environment you are in. This helps ensure you are in a rest and digest state and your body can break down your food properly.
To help activate the vagus nerve and support this parasympathetic state, before eating we can also take a couple of big deep belly breaths to ensure the body is prepared for the incoming food.
Reduce stress and relax
Of course, reducing stress can be easier said than done, but relaxation practices such as yoga and meditation can go a long way towards lowering stress levels. When you’re stressed, your sympathetic nervous system is activated, and your digestive function is impaired. Again, adding in a few moments in your day to spend some time in deep breathing practices can stimulate the vagus nerve, which can help support digestion and a healthy gut-brain axis. Practices such as mindfulness and mediation can also help activate our parasympathetic nervous system and support both a healthy digestive and nervous system.
Is there one small tweak you can make today to make your gut and brain a little happier?
Follow Kate Shore for more tips on how to nurture your gut-brain connection.
Written by Kate Shore, Naturopath