When we think of supporting immunity a few well-known tricks come to mind – lemon, ginger and honey, vitamin C, and the herbal all-star, echinacea. The lesser-known hacks for immunity involve focusing on your gut, where approximately 70-80% of the immune system lives!
The gut-associated lymphoid tissue (GALT) is the largest immune organ in the body. It surrounds your small and large intestines and is packed with a variety of immune cells, all ready to take action on any unwanted invaders. This has an important interconnection with the gut microbiome, which houses trillions of bacteria and is a major control hub for many aspects of our health.
Along with the GALT and microbiome, the gut lining and its mucous layer make up our major defence against infection.Often being the first contact with not only food, but also bacteria and viruses, the gut plays a huge role in deciding if these are friend or foe. All of this means that if your immune system isn’t toeing the line, your gut might be the reason.
Compromised gut health can make the immune system more vulnerable. The balance can be thrown out by many things including chronic stress, antibiotics, the contraceptive pill, alcohol, and a poor diet including too many processed foods and refined sugar and not enough nutrients.
Consider that your immune system, and therefore your gut, might need a hand if you’re often catching a cold or flu, have persistent or slow-healing infections or wounds, cold sores, fatigue, candida, autoimmune conditions, asthma or allergies.
Balance your gut bugs
The bacteria that make up the microbiome can be beneficial or pathogenic i.e., good or bad guys. A comprehensive stool microbiome test via a practitioner is the best way to assess the makeup of your microbiome and whether there are bad guys that need specialised handling. Sometimes antimicrobial action is required and there are powerful herbs for this which you can talk to your practitioner about.
Mostly, the diversity of the microbiome plays an important role in keeping the bad guys in check. When good bacteria are plentiful, the bad guys are out crowded and have less chance to take over, lessening the threat to the immune system.
An easy way to introduce good bugs to your gut is by increasing your intake of fermented foods, which are high in probiotics (good guys!). This also helps create an environment where your own bacteria really thrive. These foods include natural yoghurt, kefir, sauerkraut, kimchi, tempeh, miso, and kombucha. If you are new to these foods, start with a small amount daily and slowly increase as your body adjusts.
Feed the good guys
The diet is the number one fuel source for our microbiome – bacteria eat what we eat, so what you feed them matters. Building a diverse gut microbiome is the goal, which means diverse foods – variety is key.
More specifically, prebiotics are types of fibre which become food for the probiotics, such as inulin, fructo-oligosaccharides (FOS) and galacto-oligosaccharides (GOS). Making sure your diet is plentiful in these will mean happy gut bugs and a strong immune system. Some of the best prebiotic foods include asparagus, garlic, onion, leeks, Jerusalem artichoke, legumes, bananas, and oats.
Another type of beneficial fibre is resistant starch. Being resistant means it avoids enzymatic breakdown, allowing it to make the journey down to the intestine where it acts as fuel for the bacteria there. Once the bacteria ferment resistant starch, they produce short chain fatty acids (SCFAs) – a powerful form of fuel for gut cells. SCFAs also reduce gut inflammation and improve gut integrity.Sources of resistant starch include cooked legumes and starchy vegetables like potato, sweet potato, pumpkin and rice, that are cooked and then cooled.
If you have irritable bowel syndrome (IBS), small intestinal bacterial overgrowth (SIBO) or food intolerances, not all of these prebiotic and probiotic foods will be suitable for you, this is something to discuss with your practitioner.
Beware immune suppressors
The microbiome isn’t a fan of sugar, refined sugar being its arch nemesis. Refined sugar can feed bad bacteria and also affect the growth of the good guys. The typical Western diet, high in sugar, trans and saturated fats and low in fibre, good fats and micronutrients, compromises the gut lining (i.e., contributes to leaky gut) and stimulates the immune system to produce inflammation.
Gluten, dairy, alcohol and even coffee can also affect the gut lining and bacterial balance so these are best kept to a minimum, particularly during times of low immunity. Swap refined sugar and processed sweets for small amounts of quality dark chocolate (over 70%), fruit, maple syrup, fresh dates or raw honey.
In a nutshell…
The gut is the largest immune organ and is happiest when fed a variety of plants, including prebiotic fibres and probiotic foods. The Mediterranean diet is a great example of this and has been shown to reduce inflammation and therefore the risk of illness.
Aim for 40 different plant-based foods per week including vegetables, fruits, beans, grains, nuts, seeds, herbs, and fermented foods, and your gut will be thanking you with a strong immune system and abundant energy!
If you would like guidance with this, or an investigation into the health of your gut, speak with a gut-focused practitioner like a naturopath, nutritionist, or functional integrative doctor.
Leila is a qualified naturopath based in Melbourne. She specialises in chronic digestive conditions like irritable bowel syndrome, small intestinal bacterial overgrowth and leaky gut, and is passionate about eating a well-balanced diet, while still enjoying food. She believes living well doesn’t have to be a chore, and is keen to show us all how to manage our health – and enjoy it, too.
Leila will be blessing us with some of her best guidance and tips to succeed in our upcoming sugar-free program, so check out her website and stay tuned!