Naturopath Casey Wise unpacks the fascinating connection between gut health and your immune system.
A healthy gut needs two key components — a healthy and intact gut lining, and a diverse and balanced microbiome. When these components are compromised, the gut becomes dysfunctional and over time can trigger autoimmune disease. Let’s take a closer look.
Immunity and your gut: a symbiotic relationship
A permeable or ‘leaky’ gut lining allows pathogens, undigested food proteins, and toxins to leak through the intestinal barrier and into the bloodstream. Inflammation and immune system activation result as these foreign particles are marked as threats to the body which, over time, can trigger issues such as food sensitivities and autoimmunity.
The microbiota that reside in the gastrointestinal tract further influence your immune system’s equilibrium. With 70–80 percent of the body’s immune cells also residing in the gut (in gut-associated lymphoid tissue), the two have a symbiotic relationship to ensure that the body is protected from any harmful pathogens it may encounter.
Our gut microbes act as sensors within the intestinal epithelium, and fire off signals when foreign bacteria are detected; this then mobilises immune cells (such as neutrophils, macrophages, T cells and B cells) into action. When dysbiosis is present however, this process is impaired, and the gut microbiota lacks the resilience and diversity required to establish healthy and balanced immune responses.
Pathways to healing
Understanding that the health of the gut determines the health of the immune system opens up new treatment avenues for those suffering from autoimmune conditions. Your health practitioner may recommend investigating intestinal permeability (‘leaky gut’), and working to heal and seal the gut lining. Another possible path is to investigate bacterial imbalance, and work to nourish healthy gut flora and improve the diversity of microbes.
Anti-inflammatory foods
From a nutritional standpoint, a good start is to reduce the consumption of inflammatory foods that damage the gut lining, such as refined carbohydrates and sugars, trans fats, processed meats, and alcohol. Instead, centring the diet around antioxidant and anti-inflammatory nutrients like the ones listed below will help to nourish the gut lining and strengthen immunity:
- Vitamin A: Carrots, apricots, pumpkin, peaches, egg yolk, green leafy vegetables
- Vitamin C: Berries, citrus fruits, kiwifruit, papaya, broccoli, cauliflower
- Vitamin E: Almonds, sunflower seeds, sesame seeds, extra virgin olive oil
- Zinc: Oysters, shellfish, cashews, Brazil nuts, sunflower and pumpkin seeds
- Omega 3s: Fish, fish oils, chia seeds, flaxseeds, walnuts, seaweed, tofu
- Turmeric and ginger: Fresh or ground
Incorporating a mix of prebiotic and probiotic foods into your diet can assist in repopulating beneficial gut bacteria and improving the diversity of the microbiome. Prebiotics are special plant fibres that cannot be digested by the body but serve as food for the beneficial bacteria of the gut, while probiotics are live bacterial strains that are naturally contained in fermented foods.
Here are some examples of both:
Prebiotics
- Resistant starch: Cooked and cooled potatoes e.g. a cold potato salad
- Inulin: Garlic, onion, leeks, asparagus, artichokes, green bananas, rolled oats
- Pectin: Apples, citrus peels, apricots, peaches
Probiotics
- Sauerkraut and kimchi
- Kombucha
- Yoghurts and kefir
- Tofu and tempeh
- Miso
Words by Casey Wise for Endeavour College of Natural Health
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Interested in nutrition science? Learn more about how nutrition affects your overall wellbeing through Endeavour College of Natural Health’s Bachelor of Health Science (Nutritional and Dietetic Medicine) and range of Nutrition Short Courses.
