With about 70% of our immune system being housed in our gastrointestinal tract or gut, keeping it in good shape should be a top priority for all of us – so have you got the guts to be healthy?!
The gut is home to trillions of beneficial bacterial cells which outnumber our human cells by up to 10 times. Research in recent years is also linking the balance of these micro-organisms to our mental health.
The Role of the Gastrointestinal System
The gastrointestinal system encompasses the mouth, oesophagus, stomach, pancreas, liver, gallbladder, small intestine, colon, rectum and anus.
Our health is influenced by the many species of micro-organisms that populate the gut, as they help to regulate our immune system, protect the body from infection, promote normal digestive function, keep the gut barrier intact and produce certain nutrients and compounds amongst other roles. So, it is vital to our wellbeing to keep them in good balance.
It probably comes as no surprise to you that other factors such as diet, stress, the environment, and medications all have a role to play in the health of our gut. These may fuel an imbalance in our microbiota and/or an overgrowth of less desirable organisms; this may lead to a compromised digestive system, with knock-on effects elsewhere in the body including the brain.
Gut symptoms that may indicate that it’s not working well include:
- Stomach pains
However, even if you feel that you have the perfect digestive system, health issues occurring elsewhere – from headaches or mood disorders to obesity – may be attributable to some extent to poor microbial balance. It was said by Hippocrates, the ancient Greek physician, that:
All diseases begin in the gut.”
How Microbiota affects Mood
As mentioned above, the microbiota is involved in the production of certain compounds, particularly the following neurotransmitters:
- GABA – the calming brain chemical, helping ease those feelings of anxiety, stress and fear. It applies the brakes and induces a sense of relaxation and may assist with sleep.
- Serotonin – this is your “happy hormone” that helps with mood regulation. It’s also a precursor to melatonin, your sleep hormone. Interestingly, most of the serotonin in your body is found in the gut.
- Dopamine – is also known as your feel-good hormone and is linked to pleasure and reward.
A healthy gut ecosystem will also facilitate the production of B-vitamins which contribute to many varied roles in the body including acting as important co-factors in the synthesis of neurotransmitters and energy.
A substance that is really important for brain function is BDNF, Brain-derived neurotrophic factor. BDNF helps prevent the death of existing brain cells, stimulates the growth of new brain cells, and supports cognitive function. Research shows that it may be influenced by certain bacteria in the gut and help reduce depressive-like symptoms and cognitive decline.
An imbalance in your gut eco-system may increase the production of endotoxins such as Lipopolysaccharides (LPS), which are generated as undesirable bacteria disintegrate; this may break down the intestinal barrier leading to leaky gut, allowing the LPS to enter the blood stream. This may then compromise the blood brain barrier leading to inflammation in the brain which has been linked to depression.
How to Improve the Microbiota Balance in the Gut
Of course, you could take a prebiotic and/or probiotic but as different species of bacteria and even different strains, do different things in the gut, you might like to seek professional advice before starting a course of probiotics.
You may often be recommended to take probiotics if you are on a course of antibiotics which may kill all bacteria, not just the bad guys. To lessen the eradication of the good bacteria, remember to take the probiotics at least 2 hours apart from taking the antibiotics.
Diet-wise, increasing your fibre intake and consumption of fermented foods and polyphenol-rich foods, whilst avoiding a high-fat diet, may help improve your microbial balance.
Some polyphenol-rich foods to increase:
- Purple carrots
- Purple or red potatoes (consume with skin on)
- Red cabbage
- Red onions
- Black rice
- Red or black quinoa
- Red apples
- Black grapes
- Black olives
You’ve probably noticed a trend above! Yes, colourful and dark foods are full of polyphenols, antioxidant compounds with far-reaching positive health effects beyond increasing beneficial bacteria.
Another wonderful addition to your diet are prebiotics; prebiotics are used as a source of fuel to help promote the health of the good bacteria, thus improving the microbiota’s ecosystem. Readily-available prebiotic foods include:
- Apples (stewed)
Keeping your gut healthy is an integral part of enjoying overall health and wellbeing. If you’d like to find out more on how you can better take care of the health of your gut and work with a nutritionist, I welcome you to make an appointment with me.
Author: Beverley Dorgan, BHSc Nutritional Medicine, ANTA.
Beverley Dorgan is a Brisbane Clinical nutritionist with a special interest in how the foods we consume can impact on our mental health from anxiety and depression to OCD and behavioural or learning issues.
To make an appointment try Online Booking. Alternatively, you can call Vision Psychology Brisbane on (07) 3088 5422.
- Bested A – Intestinal microbiota, probiotics and mental health: from Metchnikoff to modern advances: part III – convergence toward clinical trials https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3605358/
- Cryan JF – Mind-altering microorganisms: the impact of the gut microbiota on brain and behaviour http://www.inpp.info/konferenz2014/download/nrn3346.pdf
- Maes M – The gut-brain barrier in major depression: Intestinal mucosal dysfunction with an increased translocation of LPS from gram negative enterobacteria (leaky gut) plays a role in the inflammatory pathophysiology of depression http://www.drperlmutter.com/wp-content/uploads/2015/04/9-LPS-depression-copy.pdf
- Mayer EA – Gut microbes and the brain: paradigm shift in neuroscience https://www.jneurosci.org/content/jneuro/34/46/15490.full.pdf
- Said HM – Recent advances in transport of water-soluble vitamins in organs of the digestive system: a focus on the colon and the pancreas http://ajpgi.physiology.org/content/305/9/G601