Why is gut health so crucial for a strong immune system?
70% of our immune system is housed in our gut. So, if our gut microbiome is not optimized or is in a state of dysbiosis, it’s going to directly impact our immunity. There are specific “good” species of bacteria that are associated with better health outcomes, and some that are associated with poor outcomes. And the relationship goes both ways: our immune system and general health status can influence our gut health, and our gut microbiome can influence our immune and inflammatory response. Certain cells in the lining of the gut spend their lives excreting a ton of antibodies into the gut, and this directly influences our ability to fight off disease and impacts virtually every other system in the body.
How can altering your diet improve immune health? What advice would you give someone looking to make lifestyle changes to support their gut and immune health?
A healthy gut microbiome requires a wide range of different beneficial bacteria that help to support a healthy immune system. To help support a healthy diverse microbiome, we need to think about probiotics (the actual good “bugs”) and prebiotics (the food for the bacteria). We can also discuss postbiotics, which are the waste products left behind when your body digests probiotics and prebiotics (i.e. Vitamin K, amino acids and antimicrobial peptides). Probiotics are found in fermented foods like yogurt, kefir, miso, sauerkraut and pickles, and prebiotics are found in fibre-rich foods like fruits, vegetables, legumes, nuts, seeds and whole grains. Therefore, the best diet to support microbiome diversity with the “good bugs” that help support a healthy immune system is a predominantly plant-based diet. This doesn’t necessarily mean we need to eliminate all animal products, rather we want to focus on getting in a fibre-rich diet made up with a wide variety of plants. Most North Americans don’t get enough fibre, so aiming for that goal of 25-38 grams per day can make a huge difference for our gut.
How do antioxidants play a role in maintaining good immune health and gut function? Where can these antioxidants be found?
The job of antioxidants is to prevent oxidation or free radical damage caused by cellular or external stressors like UV rays, cigarette smoke, pollution and certain food components like nitrates. Free radicals are unstable molecules that can buzz about the body and damage membranes, DNA, enzymes, etc. and ultimately lead to disease. Antioxidants help to stabilize these free radicals before they can cause damage. Research does suggest that certain antioxidants can help to support a healthy immune response. These influence vitamin E, C, Beta carotene, flavonoids, selenium and zinc. There are actually over 8,000 antioxidants, but these are the VIPs. We generally find antioxidants in fruits, vegetables, green tea, nuts, seeds, olives, legumes and eggs.
What are some causes of bloating, how does it affect immune health and what can be done to alleviate it?
There are so many reasons for bloating, so the solutions will be highly individualized. Food intolerances, sensitivity to FODMAPs, swallowing too much air (i.e. drinking carbonated beverages or through straws), undereating or disordered eating (which can slow gut motility), poor fibre and water intake or too much fibre, hormone shifts (i.e. during the PMS phase of your cycle), functional gut disorders, infection or overgrowth, thyroid dysfunction, trauma to the gut-brain axis, and anxiety can all cause bloating. If the cause of bloating is due to dysbiosis of the microbiome where there is an imbalance of good and bad bacteria, it can absolutely contribute to immune suppression. Because dysbiosis and overgrowths can be a delicate balance of getting the right amount of the right strains of probiotics, I recommend working with a dietitian to evaluate your symptoms and help put together a diet and supplement regimen that will help without risk of doing harm. But generally speaking, I recommend focusing on those antioxidant-rich plant-based foods to help feed the good bacteria in the gut and reducing your intake of highly processed high sugar foods, which can encourage the proliferation of “bad bugs”.
