How good gut health can boost your immunity

While you are reading this, a team of strangers is inside your gut, working to produce vitamins and chemicals that your body wouldn’t otherwise make. It’s all part of the gut microbiome, an entire ecosystem – made up of bacteria, small amounts of fungi, viruses and single-celled organisms called protozoa – that numbers up to 100 trillion microbial cells, averages 500 species of bacteria and can weigh up to 3kg.

Their mere presence isn’t nefarious. In fact, when balanced right, these bacteria are incredibly healthy. And understanding the balance of bacteria in your body’s gut microbiome can be the key to unlocking good health far beyond the gut itself. ‘More than half of the body’s immune system resides in the gut,’ says naturopathic doctor Sally Horrobin. ‘The gut microbiome plays a key role in protecting us from pathogens, teaching our immune system what is a friendly substance and what to attack. Research is starting to indicate that the gut microbiome has more impact on our health than we’ve ever thought possible. An unhealthy gut can result in symptoms such as frequent coughs and colds, headaches, foggy brain, weight gain, mental disturbances such as anxiety and depression, eczema and acne, premenstrual tension, and other hormonal imbalances.’

From 2007 to 2016, the United States National Institute of Health sponsored the Human Microbiome Project, which gathered information on the balance of good and bad microbes in the body and their effect on health. In your gut, as in life itself, balance is everything. Gut microbes protect us from unhealthy pathogenic bacteria, viruses and fungi, but an imbalance can lead to inflammation and chronic disease.

‘Crucially, this ecosystem within your gut looks after and repairs your gut wall,’ says Horrobin. A dramatic reduction of good gut microbes can lead to permeability, known as having a ‘leaky gut’. The National Finrisk Study, which followed more than 2000 Finnish people for 10 years, found that those with gut permeability, linked directly with imbalanced gut bacteria, also had an increased risk of obesity, diabetes and cardiovascular problems.

Boost your bacteria

The good news is, you can achieve a healthy gut through food and exercise. Sally Horrobin explains how…

Eat a rainbow ‘The different colours and flavours found within the plant kingdom are known as phytonutrients and contain powerful healing properties that can improve gut health. You also encourage a more diverse gut microbiome by including many different plant compounds.’

Enjoy prebiotic foods daily ‘Prebiotics are indigestible carbohydrate molecules that nourish and stimulate the growth of good bacteria while promoting a reduction in disease-causing bacteria. Foods that have high amounts of prebiotics include asparagus, avocados, bananas, aubergine, garlic, legumes, beetroot, onions, peas, leeks, oats, dairy (if tolerated) and sweet potatoes.’

Try fermented foods ‘Kefir, sauerkraut, kimchi, yoghurt, kombucha, miso and fermented vegetables are “pre-digested”, and contain live beneficial bacterial strains that enhance our gut microbiota.’ Give these a try to boost your gut health.

Read more: 5 things to remember when making fermented foods

Add foods high in resistant starch ‘Beans, cooked and cooled grains, green bananas, cooked and cooled potatoes, nuts and seeds are all good sources. They increase healthy gut bacteria by resisting digestion in the small intestine and acting as a food source for bacteria which mainly colonise the large intestine.’

Use ground flaxseeds and chia seeds to ensure regular bowel movements ‘At breakfast, add a heaped tablespoon of each to yoghurt, porridge or apple sauce. They are rich in prebiotic fibre to support your gut bacteria, and they contain all-important omega-3 to help support heart and brain health.’

Stay fit ‘We think of doing exercise to strengthen our muscles, bones and heart, but keeping fit also benefits our gut microbiome. Exercise improves the blood flow to the abdominal cavity and intestines, and movement stimulates and tones the digestive tract, promoting healthy digestion.’

Read more: Why healing your gut could make you happier