How much of your immune system is in your gut?

You may know that your immune system and your gut are closely linked, as this is known as the Gut-Immune Connection. But, just how much of your immune system is in your gut exactly - and what does this mean for you from a holistic health perspective? 

Roughly 70% of your immune system lives in your gut. More specifically, gut-associated lymphoid tissue (GALT) represents almost 70% of the entire immune system, and 80% of plasma cells [mainly immunoglobulin A (IgA)-bearing cells] reside in GALT. 

This substantial population is a testament to the critical role of your gastrointestinal system in immune system homeostasis ( Vighi, G, et al., 2008 ).

Translation: Your digestive system, along with everything that passes through it, plays a key role in your immune function and overall health. 

So, find out what you can do to optimize your gut health immune system connection below! 

How Much of Your Immune System is In Your Gut?

So, how much of your immune system is in your gut? Like we said before, 70% of the immune system is in the gut. Let’s progress the conversation though and narrow our focus on the GI tract and the microbiome. 

Consisting of the stomach and small and large intestines, the gut is home to a vast array of bacteria, often termed the gut microbiome (your body has other microbiomes, too!). The gut microbiome plays a big role in the physiological processes of the body, including digestion, nutrient absorption, immune regulation, and metabolism. 

When it comes to the way that the gut microbiome influences the immune system, it's a journey that begins at birth. Newborns start with a sterile gut that is colonized by bacteria that the baby acquires from mom and the surrounding environment. 

This early exposure to microbes (bacteria) influences the development of the immune system and its ability to differentiate between harmful and harmless substances. 

The microbiome also helps immune cells mature and helps form the GALT we talked about earlier. Think of the GALT immune cells as patrolmen, monitoring the gut and initiating responses against potential threats. 

The gut-immune connection is a dynamic one where both your diet and your microbiome can play a role. Studies have determined the gut microbiota metabolizes proteins and complex carbohydrates, synthesizes vitamins, and produces metabolic products, like short-chain fatty acids, that can mediate cross-talk between the two ( Yoo, Ji Youn, et al., 2020 ).

We could dig into the nerdy details about innate and adaptive immunity, but at a high level, it's as simple as gut bacteria communicating with immune cells to control how your body responds to infection. 

Commensal microorganisms are needed to teach the immune system to differentiate between commensal and pathogenic bacteria ( Lazar, Veronica, et al., 2018 ). Over time, the symbiotic relationship evolves to promote overall health and immune function.

Where is the Rest of the Immune System Distributed?

Knowing how much of your immune system is in your gut, you may be curious about where the rest of it is located. Here’s a quick breakdown of the other 30% of your immune system:

• Lymph Nodes: These small, bean-shaped structures are crucial hubs where immune cells filter pathogens from the lymph fluid. Distributed along the network of lymphatic vessels, they are gatekeepers that trigger immune responses.
• Bone Marrow: Located in the hollow centers of certain bones, bone marrow is vital for producing blood cells, including various types of immune cells. It acts as a nursery where immune cells mature before they patrol the body.
• Thymus: Situated behind the sternum and in front of the heart, the thymus is where T-cells mature. These cells are essential for adaptive immunity, which tailors the body's immune response to specific pathogens.
• Spleen: This organ filters blood, removing old red blood cells and holding a reserve of white blood cells and platelets. It plays a significant role in fighting bacteria and other pathogens that invade the bloodstream.
• Mucosal Associated Lymphoid Tissue (MALT): Found in the mucosal linings of the respiratory and gastrointestinal tracts, MALT protects these vulnerable entry points by producing immune cells directly at the site of potential pathogen entry.

Together, these organs and tissues form a highly interlinked and dynamic system that monitors and responds to threats throughout the body. So let’s talk about what you can do to support the gut health immune system connection below.

Practical Tips on Supporting Gut Health and Immune System Simultaneously

You can think of your gut microbiome as a gatekeeper to your immune system. Knowing how much of the immune system is in the gut, it’s worth taking measures to boost your gut health and thereby your immunity. 

Many factors affect your gut microbes, like the environment, medications, lifestyle choices, and eating habits. While there are many factors we cannot control, the latter of the two can be the easiest to manipulate. 

According to experts at UCLA Health, the immune cells housed in the gut are directly influenced by diet and lifestyle. Here are three dietary changes you can make now to take control of the power your gut microbiome has:

1. Eat Foods High in Dietary Fiber

The bacteria in your gut are healthiest when you eat foods packed with dietary fiber like fruits, vegetables, nuts, whole grains, and legumes. 

Bacteria digest the fiber and produce short-chain fatty acids (SCFAs) that, in return, nourish the gut barrier and improve immune function ( Morrison, Douglas J, et al., 2016 ). An added bonus is that fiber helps slow gastric emptying, meaning it will also help keep you feeling full and balance your blood sugar in the process. 

2. Eat Fermented Foods

Eating fermented foods such as yogurt, sauerkraut, kefir, kombucha, and kimchi can help boost the number of beneficial bacteria in your gut. These bacteria, also known as probiotics, are associated with various health benefits like improved immunity and digestion (King, Sarah, et al., 2014).

You can also pickle your own vegetables, like cucumbers, onions, and carrots. This is another great way to get beneficial probiotics! 

3. Eat Prebiotic-Rich Foods

Prebiotic foods including chicory root, Jerusalem artichoke, garlic, onions, and asparagus promote the growth of beneficial bacteria in your gut. 

These foods are primarily forms of fiber that human cells cannot digest, so the bacteria ferment them to use for fuel and, in turn, provide several systemic health benefits (Slavin, Joanne 2013). 

Most people do not eat enough prebiotic-rich foods in their diets. Incorporating more prebiotic-rich foods and supplements is a great way to support the beneficial bacteria in your gut and keep your gut microbiome happy and healthy. 

While every person is different, your body and gut health will likely need more support than diet changes alone, but it is a great start. As always, make sure to discuss any significant changes with your doctor or a qualified medical professional.

Closing Thoughts on How Much of the Immune System is in the Gut

So, how much of the immune system is in the gut? In conclusion, the gut plays a pivotal role in overall immune system health, housing approximately 70% of its infrastructure. 

Remember, the choices you make about what you eat significantly influence your gut microbiome, which in turn, impacts your immune system's effectiveness. 

By nourishing your gut with dietary fibers, fermented foods, and prebiotic-rich choices, you enhance your gut health immune system function and contribute to your overall well-being. 

We have resources on the vasaka leaf benefits, how to detox your gut health, herbs for lung health, probiotics for lung health, holy basil properties, and more.

 

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These are expert opinions on lifestyle from professionals who are board-certified physicians, registered dietitians, or healthcare professionals. This content does not represent any medical advice for the prevention or treatment of any medical diseases.