- Have you ever gone through a stressful experience and noticed that your appetite disappeared?
- Have you had constipation and noticed how lethargic, irritable, and low in mood it made you feel?
- Have you ever been really anxious and felt ‘butterflies’ in your stomach, or noticed you needed to run to the toilet multiple times?
That’s your gut and your brain talking to each other, and they do it all the time!
BeyondBlue tell us that in any one year, around one million Australian adults have depression, and over two million have anxiety. As many as one in five Australians will suffer from IBS (irritable bowel syndrome), just one type of gut problem, during their lifetime. Research shows us these two things are not coincidental.
Depression, anxiety and stress interact with gut problems like stomach pain, constipation, diarrhea, irritable bowel syndrome, and nausea. Studies indicate that stress changes the levels of gut bacteria, contributing to symptoms of anxiety and depression. There is also evidence that gut problems can predict future anxiety problems, and that rebalancing gut bacteria has a positive influence on both current and future mental health.
Do I have a second brain?
The gut has been called our ‘second brain’ because of the important role it plays in our mental health.
During the 19th century, Western doctors believed poor gut health caused mood, thought and behaviour problems.
In the 20th century, Western doctors were more likely to believe that poor mental health was the cause of many gut problems.
Now, in the 21st century, there is a growing understanding that both gut and brain affect each other in what is called a ‘bi-directional’ relationship. They talk to and influence each other.
Just how do my gut and brain talk to each other?
We all have gut bacteria, right from before we are born, and we need these ‘good’ bacteria to be healthy and well. The levels and diversity of bacteria can change due to stress, diet, and antibiotics, and these changes have significant effects on our body and our mental health.
The gut-brain axis refers to the three pathways through which the gut and brain talk to each other, and in which a range of complex things happen. For example, if we are stressed, this changes our gut bacteria so that we release more cortisol (the stress hormone) and it is able to move through more parts of our body resulting in pain, fatigue and anxiety. Our gut triggers an inflammation response to stress and infection, and this can increase depression, anxiety, and pain sensitivity. By rebalancing our gut bacteria with food, anti-depressants, or activities that reduce stress, we can reduce the release of cortisol and increase the release of dopamine, which is a hormone promoting relaxation and positive mood.
How can I care for my gut-brain health?
By taking an holistic approach, you can look after both your brains!
Pre-biotics are a type of fibre that we get from food. It passes through our gastro-intestinal tract undigested and stimulates the growth or activity of certain ‘good’ bacteria. Foods that act as pre-biotics include vegetables, legumes, fruit, breads and cereals, nuts and seeds (and human breast milk!).
A few tips to increase your fibre intake:
- Eat a high-fibre breakfast cereal and add nuts, seeds, and dried fruit
- Add a few tablespoons of bran or psyllium husks to cereal, soups, casseroles, yoghurt.
- Eat wholegrain breads
- Eat fruit and vegetable skins, don’t peel them
- Snack on fruit, nuts, and seeds
- Eat legume or lentil-based dishes a few nights a week (e.g. felafel, chickpea salad, dhal, add lentils to casseroles, salads and soups)
- Eat fruit instead of drinking fruit juice or soft drink
If you’ve been diagnosed with IBS (irritable bowel syndrome), seek the guidance of your doctor.
Probiotics are a way to get more good bacteria into your gut, and these can be through fermented foods or dietary supplements. There is no recommended daily intake for probiotics, so just add what you can to your diet. The most common fermented foods that contain probiotics include: yoghurt, kefir, kombucha, sauerkraut, pickles, miso, tempeh, kimchi, sourdough bread, and some cheeses.
Stress-reducing techniques and activities contribute to improvements in both your mental health and your gut health. Try things such as:
- spending time in nature
- spending time with pets and friends, on hobbies and things you enjoy
- exercise (walking, running, swimming, yoga)
- meditation, mindfulness, and visualisation
- progressive muscle relaxation
- breathing exercises
- counselling and psychological support
References & resources
‘Gut-Brain Axis and Mood Disorder’, Frontiers in Psychiatry: https://www.frontiersin.org/articles/10.3389/fpsyt.2018.00223/full
‘The Gut-Brain Axis: historical reflections’, Microbial Ecology in Health & Disease: https://pubmed.ncbi.nlm.nih.gov/30425612/
‘Prebiotic Diet FAQs’, Monash University: https://www.monash.edu/medicine/ccs/gastroenterology/prebiotic/faq
‘How to get more probiotics’, Harvard Health Publishing: https://www.health.harvard.edu/staying-healthy/how-to-get-more-probiotics