How improving your gut health can help support your immune system

Staying healthy year-round is always a priority, and a strong immune system plays a big role in keeping you feeling your best.
Your immune system is your body’s first line of defence against illnesses and it’s made up of a complex network of cells, tissues and organs found in a variety of locations including your skin, spleen, lymphatic system and, most significantly, your intestines. But did you know that a significant part of your immune function is tied to the health of your gut?
“About 70 per cent of our immune function is centred in the gut,” explains accredited practising dietitian Dr Joanna McMillan.
Your immune system relies on key nutrients to function properly, and a healthy gut ecosystem plays a big role too. Read on to learn more about how your gut microbiome supports immunity.
So, what should you be eating to keep your gut (and immune system) in check?
What is the gut microbiome?
The gut microbiome is a collection of more than a trillion microorganisms such as bacteria, fungi and viruses living in your gut – ideally, in harmony. A healthy gut microbiome is one with a high diversity of microbes, and more of the ‘good’ type of bacteria than the ‘bad’. But when that balance is disturbed by factors such as a poor diet, illness or stress, the resulting disharmony – known as dysbiosis – could make the body more susceptible to disease.
Dietary strategies to support your gut
1. Load up on fibre
According to Joanna, the best way to feed your microbiome is to eat a diet rich in fibre, which is a type of carbohydrate that doesn’t get broken down like most other foods we eat. Instead some fibres travel to the gut where they are fermented, and the by-products of that process communicate with our immune system, Joanna explains.
“The most important thing is a diversity of different fibres,” she says. “Just taking fibre supplements is not the same as eating a plant-rich diet, which gives you lots of different types of fibres.”
Consider adding these foods to your lunch or snacks throughout the day:
Whole grains (not refined grains)
Legumes (beans, lentils, chickpeas)
Fresh fruits and vegetables
Nuts and seeds
Another important type of fibre is prebiotic fibre, which helps stimulate the growth of beneficial gut bacteria. You can find prebiotic-rich foods in:
Beetroot
Asparagus
Chickpeas
Red kidney beans
Nectarines
Watermelon
Dried dates
Oats and whole wheat bread
Just be mindful not to overdo it as too much prebiotic fibre can lead to bloating and gas. And remember, when increasing your fibre intake, you also need to drink plenty of water.
Related: The sources and benefits of fibre
2. Incorporate probiotics
If you’re looking to support your gut to be as healthy as it can be, eating probiotic foods – not to be confused with prebiotics – is also a good idea. Probiotics are a group of live microorganisms that help harmonise the balance of good and bad bacteria in the gut. They also secrete protective substances that help activate the immune system and block pathogens from creating major disease. Common sources of probiotics include:
Miso
Kimchi
Yoghurt
Kefir
Pickled vegetables like sauerkraut and pickles
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3. Boost your gut health with polyphenols
Polyphenols are chemical compounds found in plant-based foods that have antioxidant properties. These compounds can help fight inflammation and support gut health. Good news, tea and coffee are rich in polyphenols, so your next coffee date could be doing wonders for your gut health. Joanna says you can also find polyphenols in cocoa, red wine (in moderation!), berries, pomegranates, leafy greens, herbs and spices.
Related: How to reduce alcohol and stay social
What to avoid: gut-health foes
Of course, not all foods are good for your gut – some are actually detrimental to intestinal function. That includes foods high in artificial sweeteners (such as soft drinks), emulsifiers (found in processed foods such as ice-cream), excessive amounts of meat and (for some people) dairy.
“Limiting stress and not smoking are also two ways to keep your gut microbiome healthy,” says Joanna. Being mindful of your stress levels can really support your gut health. Simple habits like taking breaks, practising mindfulness or meditation and practising self-care can have a positive effect. Find more mental wellbeing articles on The Check Up.
The information contained in this article is provided as general information only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. For personalised medical advice, always consult your qualified healthcare professional.