How Gut Health and Your Immune System are Related

Gut health profoundly impacts just about every aspect of human health, and immune function tops the list. The gut microbiome consists of trillions of microbes, so many that they outnumber human cells by a ratio of ten to one. Many health experts consider the gut microbiome to be its own organ.

When you hear the words ‘microbes’ and ‘bacteria,’ this may bring to mind illness. However, each person’s microbiome configuration is unique, and the key is striking a harmonious balance of microbes that directly impact both gut and immune health. With the right foods and supplementation, you can promote the health of your gut and support a robust immune system.

What is a healthy gut?

First and foremost, it’s essential to understand the foundations of gut health and how the gut functions. The gut holds between 50 to 100 trillion bacteria, and the outer wall of the intestinal lining consists of microbes. That outside portion is referred to as the mucosa, which works in concert with your bacteria to break down food, extract nutrients, and eliminate what the body doesn’t need.

The gut is the initial line of defense. For example, if you are traveling, eating new foods, and being exposed to different bacteria, you may experience bloating, loose stools, or general discomfort as your gut adjusts and responds to protect your body against foreign invaders.

How Your Gut Talks to Your Immune System

The immune system has two major branches: the innate immune system (also referred to as the intrinsic immune system) and the adaptive immune system, which produces antibodies.

The innate immune system addresses threats via antigen-presenting cells. In cases of more serious viruses, bacteria, or other invaders, the innate branch alerts the adaptive branch to prepare for an incoming issues. A healthy gut microbiome is essential for the production of these antigen-presenting cells, and since the gut communicates with both of these branches, preparing for and dealing with pathogens can’t work properly when gut health is compromised.

Your innate immune system also produces natural killer cells, which are essentially cellular hormones that send chemical messages across the gut mucosa when any sort of issues is present. These natural killer cells are imperative for a healthy immune system as they are partially responsible for the creation of white blood cells.

Intestinal Permeability and Immune Health

Certain intestinal troubles, such as high acidity or bowel concerns, can affect your gut mucosa, resulting in  the toxins and bacteria that would otherwise be discarded from the body passing through the intestinal wall into the bloodstream. Tiny gaps in this wall are called tight junctions, which allow water and essential nutrients to pass through. 

In the case of a damaged mucosal lining, harmful substances are able to cross the barrier, potentially initiating an inflammatory immune response. Consequently, people may experience unpleasant feelings such as brain fog, skin issues, digestive discomfort, increased sensitivities to foods, head tension, and more severe health problems over time.¹

The gut acts as a security guard for the entire body, dictating what can safely come in and what must stay out. If that guard is let down, the immune system is trained to attack invaders, resulting in these undesirable issues. Promoting a well-functioning gut is critical for supporting a strong immune system.

foods that promote gut health

A well-functioning immune system depends on a diet of healthy foods that promote gut health. Without a diverse selection of whole foods rich in fiber, nutrients, protein, good fats, and complex carbohydrates, the gut can become damaged over time. Whenever possible, choose organic whole foods that are local to your area.

Fruits and Vegetables for Gut Health

Eating a variety of colorful fruits and vegetables is fundamental for gut and immune health. Not only does this provide the body with essential nutrients and antioxidants, but rotating foods can help support the immune system while avoiding overexposure.

Prebiotic and Probiotic-Rich Foods

Prebiotics are non-digestible carbohydrates found in many high-fiber plant foods. They pass through the upper section of the GI tract without being digested and are fermented in the small intestines. They are essentially food for the probiotic (good) bacterias in the gut, and food sources include Jerusalem artichoke, garlic, onions, asparagus, green plantains, and green bananas.

Probiotics are living organisms that naturally occur in the gut. They play vital roles in maintaining gut homeostasis and can be found in abundance in fermented foods such as yogurt, raw sauerkraut, kimchi, kefir, miso, tempeh, and kombucha tea.

Refined Sugar and Your Gut

In addition to increasing your intake of gut-supporting foods, reducing or eliminating foods that harm the gut, mainly refined sugars and carbohydrates, is equally as important. Processed foods containing white sugar and white flour can feed undesirable bacterias and promote fungal overgrowth.²

Doing your best to create a diet of plant foods, legumes, high-quality proteins like meat, fish, and eggs, and fermented foods will lay the foundation for a healthy gut. Set your kids up for success by offering them these same foods, as children who don’t grow up eating a whole foods diet are more likely to suffer gut issues as an adult and need supplements.*

Gut Health Supplements: Probiotics

Supplements fill in the nutritional gaps left from a history of processed and packaged food consumption, inadequate nutrient levels in soil, exposure to harmful substances and other common gut concerns.*

A diverse probiotic supplement, changed every six months, can make a massive difference to gut and immune function and provides a higher dose than foods alone.*³ Under certain circumstances there is the potential to wipe out good bacteria, which can easily lead to GI issues. During these circumstances it’s critical to follow up with a high quality probiotic supplement for additional gut health support.* 

Saccharomyces boulardii is a specific type of safe and healthy yeast that is believed to work especially well to maintain a balanced gut ecosystem.*

Go with your gut

Prioritizing gut health has a profound ripple effect on all body systems, the immune system being one. Focusing on a diet rich in varied and brightly colored plant foods, protein, and healthy fats goes a long way in promoting a healthy gut, and supplements like probiotics can fill in the gaps.* Discuss any gut discomforts or suspected problems with your integrative doctor to develop a personalized supplement plan.

[1] Visser, J., Rozing, J., Sapone, A., Lammers, K., & Fasano, A. (2009). Tight junctions, intestinal permeability, and autoimmunity: celiac disease and type 1 diabetes paradigms. Annals of the New York Academy of Sciences, 1165, 195–205.

[2] Pfaller, M. A., & Diekema, D. J. (2007). Epidemiology of invasive candidiasis: a persistent public health problem. Clinical microbiology reviews, 20(1), 133–163.

[3] https://www.nature.com/articles/nrgastro.2014.66