Do you get sick frequently and it takes you a while to recover? Maybe you end up with a secondary infection?
It could be related to your gut health, more specifically, your microbiome.
Even if you don’t have chronic digestive issues such as constipation, gas, bloating or pain, you can still have gut microbiome imbalances that impact the function of your immune system.
What is The Gut Microbiome and What Does it Do For Us?
Up to 70% of your immune system resides in your gut, more specifically, your gut microbiome. The microbiome is an ecosystem of microbes including bacteria, yeasts, viruses and parasites. This exists mainly in the large intestine.
The microbiome has many roles including:
- Digestion and absorption of nutrients
- Formation and excretion of stool
- Production of and absorption of vitamins including vitamin K
- Immune system regulation and response
How Does The Gut Microbiome Impact The Immune System?
Your immune system (white blood cells) are active throughout your body, especially at all entrances to the body – places where the body is exposed to the outside world (endothelial cells) including the sinuses, lungs and gut. However, a large portion of the body’s immune system – approximately 70% – exists in the digestive system.
Your microbiome in your large intestine includes something called the GALT – gut associated lymphoid tissue. GALT acts as the first line of defense against harmful bacteria, viruses, and toxins that come in through food and drink. It’s basically the control centre for the immune system. Gut bacteria interact with the cells of the gut lining to relay messages about whether an immune response needs to be mounted. The microbiome essentially “trains” the immune system by providing molecules and signals that stimulate immune cell activity and differentiation.
In people with a healthy balance in their gut microbiome, the immune system works efficiently to fight off foreign invaders such as bacteria and viruses by mounting immune responses that start in the gut and circulate throughout the body. It also monitors the microbiome ecosystem to keep the bacteria levels in check.
The gut bacteria send signals to the cells that line the gut, which in turn communicate with immune system cells throughout the body. This can work to help fight an infection or illness, food poisoning, or, if imbalanced, can create inflammation throughout the body and brain. This is common in a condition called leaky gut.
To further complicate things, part of your nervous system – the enteric nervous system – resides in your gut. These nerve endings send signals to your brain and the immune system to mount the proper response. This two way communication highway between the gut and the brain is one of the reasons we say you have “butterflies in your stomach” when you’re nervous, or it “made me sick to my stomach” when something is upsetting. This is why people with chronic gut issues find they get a “flare up” when they are stressed or nervous. It’s also the reason why if you’re been going through a more stressful period in your life you may get sick more easily. Or you’ve been stressed and working hard and then go on vacation and suddenly get sick.
When the gut microbiome becomes imbalanced (dysbiosis), and the the healthy bacteria that manage the immune response in the gut become depleted, or overrun by less healthy species, the immune response isn’t as strong, and you’re more likely to get sick easily and take much longer to recover.
How Do I Know If I Have An Unhealthy Gut Microbiome?
Some people have no symptoms at all, but for those that do, there are many signs and symptoms of an unhealthy gut microbiome including:
- Indigestion and food “sitting heavy” for hours
- Chronic diarrhea or constipation (despite eating healthy)
- Excessive belching after meals
- Nutrient deficiencies, despite a healthy diet and supplementation
- Acid reflux and “lump in the throat” feeling and trouble swallowing (silent reflux)
- Multiple food sensitivities
- Skin conditions such as eczema and psoriasis (related to leaky gut)
- Chronic inflammation with no known cause
- Brain fog with no known cause
To determine the balance of bacteria in the gut, advanced stool tests are used to sequence the species of microbes present in the gut microbiome. The patient submits a stool sample and it’s processed using PCR analysis, then a comprehensive report is supplied. The report indicates levels of healthy and less desirable bacteria, yeasts, viruses and parasites and also indicates:
- Markers of inflammation (calprotectin and occult blood)
- Absorption & fat digestion (steatocrit (fecal fat) and pancreatic elastase)
- Immune function in the gut (IgA, anti-gliadin and Eosinophil Activation Protein)
- Gluten reactivity (anti-gliadin IgA)
- Estrogen metabolism (B-glucuronidase)
Common tests that are used in functional medicine are the GI MAP and GI 360. Once the test results are received, your provider can review with you and build a personalized plan to support optimal gut and immune health.
How Do We Support The Gut Microbiome to Support Optimal Immune Function?
A healthy gut microbiome requires several things:
- Fibre and antioxidants to feed healthy gut bacteria
- Motility: regular bowel movements – food that sits too long ferments and creates inflammation and breeding ground for less desirable bacteria
- Movement: daily movement brings oxygen into the body and is proven to help support the growth of healthy gut bacteria
- A happy brain: due to the gut-brain connection, whatever is happening in your brain (your thoughts, emotions), is impacting your gut.
- Protein to support the gut lining and immune system function
- Minimal toxins and gut irritants (processed foods, antibiotics, painkillers)
With this in mind, you can support your immune system in your gut by:
- Getting adequate protein:
Protein is critical for a healthy gut lining to prevent leaky gut and in general for a healthy immune system. Aim for about 80 g or more per day, however everyone’s needs are unique, depending on your age and activity level. If you have digestive issues, you may find that animal based proteins like meat, fish and eggs as well as nuts and seeds are better tolerated than legumes and soy-based products. - Get Regular:
Chronic constipation creates inflammation in the gut. It allows food to sit and ferment longer than it should, creating the perfect breeding ground for undesirable, more inflammatory gut bacteria, and crowding out less healthy species. To combat constipation, ensure you’re staying well hydrated, getting adequate fibre, avoiding known food sensitivities, focusing on home cooked, whole food meals and limiting processed foods, including daily movement and managing stress. - Ditch the diets and cleanses:
Undereating starves your gut of the nutrients it needs to thrive. It also shifts your brain into “survival mode”, sending danger signals to the gut and reducing immune function. Ditch the restrictive diets. Diets such as keto, carnivore and low FODMAP all have their place, but long term they starve your gut of the fibre and nutrients it needs to thrive and maintain a healthy immune response. - Eat your fibre:
Aim for 30 grams of fibre from a variety of sources every day. Soluble fibre (the kind that dissolves in water) is food for your healthy gut bacteria. If fibre makes you bloated and uncomfortable, start slowly and try lower FODMAP options like ground flax, green beans, hemp, carrots and brown rice and oats. If you still cannot tolerate fibre, book an appointment for a personalized plan. - Getting adequate sleep:
Lack of sleep has been shown to negatively impact the gut microbiome due to stress hormone shifts. It also results in cravings for more indulgent foods, and less of the foods that feed your healthy gut bacteria. Daily movement and stress management techniques such as deep breathing can help you achieve a good night’s sleep. Know that gut bacteria imbalances can impact brain chemistry and sleep quality. If you struggle with sleep, reach out to your primary care provider for support. - Managing stress levels:
try adding in more of what brings you joy, daily movement or practices such as yoga, deep breathing, QiGong or meditation. These practices boost feel good hormones which sends good signals to the gut. This helps reduce inflammation and optimize motility and create the ideal environment for healthy gut bacteria to thrive. - Mental health matters:
If you’re feeling overwhelmed, down or worried, seek support from loved ones or from a professional. Due to the gut-brain connection, mental health has a huge impact on both digestive and immune function and food choices, and it can be hard to make consistently healthy choices when you aren’t feeling yourself. Your gut bacteria also impacts mental health by impacting inflammation in the brain as well as the balance of neurotransmitters in your brain such as serotonin, dopamine and GABA. - Home cooked meals:
Home cooked meals made from whole foods contain higher amounts of fibre and antioxidants that support the growth of healthy gut bacteria and keep inflammation low. Processed foods contain higher levels of sugar, inflammatory fats, artificial sweeteners and preservatives that can cause inflammation in the gut and impact the gut immune system. - Focus on antioxidant rich foods:
Like fibre, antioxidants are food for healthy gut bacteria. Try adding more berries and cherries, grapes, orange vegetables, green tea, citrus, broccoli, cabbage and cauliflower, onion and garlic, and spices such as cinnamon, ginger, turmeric and cloves as well as fresh herbs. - Try a probiotic:
taking a high quality probiotic can support optimal gut function and immunity in the gut. However, there are many different types of probiotics available. There is no “one-size-fits-all” probiotic – while the right probiotic can make you feel better, the wrong one may make you feel worse. It’s important to work with a practitioner to determine which one is best for you. - Fermented foods:
try incorporating more fermented foods into your diet. They’re an excellent source of naturally occurring probiotics, acids and enzymes. Try adding traditionally fermented yogourt, sauerkraut, kimchi or pickles (found in the fridge section) or a low sugar kombucha.
While there are many prebiotic fibre supplements available on the market, for many people with chronic digestive issues such as IBS, these fibres may cause more digestive upset, gas, bloating and even diarrhea. It’s best to get your fibre from food when you can, and if you’re wanting to try a supplement, work with a practitioner.
While these are all excellent initial steps to take to optimize both your digestive and immune health, keep in mind that it takes time for these changes to have an impact on the body. Be patient with your body and stay consistent – after a few months you will start to notice some shifts. It’s important to remember that what works for one person, isn’t necessarily what will work for you.
If you’re struggling with digestive issues and frequent illness, book an appointment with our functional nutritionist Holly today for a personalized gut healing plan to support your immune system this cold & flu season.
Book your appointment with Holly Bradich
Holly Bradich, Functional Nutritionist
Sage Naturopathic Clinic