The Critical Connection Between Gut Health and Immune Function

How the Health of Your Gut Affects Your Immunity

Are you aware of the critical connection between your gut and immune system? Nestled within your gastrointestinal tract is a vast and complex ecosystem known as the gut microbiome, bustling with a myriad of bacteria, fungi and other microbes. These microscopic organisms are integral not only for proper digestive function and absorption of nutrients, but also for engaging in a continuous dialogue with the vast network of immune cells working together to defend your body’s health.

Remarkably, 70% of your immune system is embedded within your gut, where it interacts with the multitude of microorganisms living in your microbiome.1Some of those microbes are friendly and helpful for healthy outcomes, while others present a risk. It’s up to the specialized immune cells residing within your digestive tract to decipher what’s friend or foe.

A healthy gut microbiome includes a diversity of beneficial bacteria that helps your immune system function at its best, while a disrupted microbiome may undermine its ability to diligently protect your health.

Understanding The GALT: Your Immune System’s Central Intelligence Center 

The vast majority of your immune cells collect in the organized lymphoid tissues found in your gastrointestinal tract known as the GALT (gut-associated lymphoid tissues). Made up of several types of lymphoid tissues, including Peyer’s patches in the small intestine, the GALT contains the largest reservoir of immune cells in the entire body (which makes sense when you think about it).2

The layers of immune cell-rich tissues are in direct contact with the external substances coming into your digestive system, making them a key location for immune surveillance. The extensive collection of specialized immune cells found in your intestinal tract survey everything that you ingest. They then have to decide what foreign substances can and should be tolerated and which must be defended against, subsequently launching an immune response.

In order to respond effectively to potentially risky microbes without inducing inflammation unnecessarily, your immune system relies on clear communication between your microbiome and immune cells.3

The Integral Link Between Gut Health and Your Immune System

As you can conclude from above, the gut microbiome and immune system are closely linked. Just as the health and function of your immune system is affected by the health and diversity of your gut microbiome, changes in your immune system can influence your gut health.

Researchers believe that the immune system and gut microbiome have actually coevolved to form a symbiotic relationship designed to protect human health. The composition and diversity of bacteria residing in your microbiome has been educating your immune cells since birth – teaching your immune system when, and when not to, launch a full-blown attack on foreign substances.

In other words, the bacteria in your gut plays a crucial role in regulating your body’s immune response. Beneficial, or commensal, bacteria send signals to the immune cells collected in the nearby GALT indicating that they are indeed friendly, while also helping them recognize unfriendly microbes that need to be eliminated. In return, your immune system helps maintain a stable community of microbiota, keeping the microbiome in balance.4

Bottom line: The communication between your microbiota and immune cells is crucial for robust immune responses as well as a balanced immune system. Therefore, maintaining a diversity of beneficial bacteria in your gut microbiome is essential for a healthy, well-functioning immune system. And a diverse microbiome of good bacteria depends on a diverse diet and healthy gut.

How To Eat for A Healthy Gut and Stronger Immunity

Regrettably, a conventional Western diet, characterized by elevated levels of saturated fats, animal proteins, sugar and processed foods, fails to foster a diverse array of beneficial microbes and instead contributes to gut inflammation.

For a diverse microbiome and healthy gut experts suggest the following strategy:

  1. Eat a variety of plant foods. A healthy microbiome relies on a diversity of fiber-rich foods, such as whole grains, beans, vegetables and fruits. As a general rule, eating an array, or rainbow, of colorful fruits and veggies – from apples and raspberries to spinach and sweet potatoes – daily will help ensure a thriving gut microbiome.
  2. Eat fermented foods. Fermented foods, especially from vegetables like sauerkraut or kimchi, contain live microbes crucial for sustaining a stable and well-balanced gut microbiome. They also contain prebiotics, which feed the beneficial bacteria in your gut. Research suggests that regularly eating fermented foods can help improve gut health and reduce inflammation.5
  3. Take a daily probiotic or postbiotic supplement. If consuming fermented foods regularly seems nearly impossible, try taking a daily probiotic or postbiotic supplement. Probiotics are live microorganisms that can help restore a healthy balance of beneficial bacteria in your microbiome and improve gut health. While probiotics are nonviable microorganisms that provide health benefits. You can learn about more about the differences between probiotics and postbiotics here.6
  4. Watch your alcohol consumption. Excessive alcohol consumption is linked to gut inflammation, disrupting the delicate balance of your microbiome. Studies indicate that alcohol-induced inflammation can result in a leaky gut and an overgrowth of harmful bacteria, thereby affecting the mucosal immune system, of which the GALT is a component.7
  5. Eat foods rich in polyphenols. Polyphenols are antioxidants that have been shown to help regulate the gut microbiome by stimulating the growth of beneficial bacteria and inhibiting bad bacteria.8 They can be found in red wine, dark chocolate, seeds, olive oil and green tea.

Interested in taking a postbiotic supplement for additional immune support? IMMUSE™ postbiotic has demonstrated the ability to directly stimulate key  immune cells situated in the GALT's Peyer's patches — offering more comprehensive immunity support that traditional immune health supplements.

Having received the Ingredient of the Year award for Microbiome Modulation at the previous NutraIngredient-USA Awards, IMMUSE continues to stand as a cutting-edge postbiotic. Its unparalleled clinical research not only showcases its safety but also highlights its efficacy in delivering comprehensive immune support.

To discover more about IMMUSE and its capacity to bolster year-round health, click the button below.

About IMMUSETM Postbiotic



1Wiertsema S, et. al., The Interplay between the Gut Microbiome and the Immune System in the Context of Infectious Diseases throughout Life and the Role of Nutrition in Optimizing Treatment Strategies. Nutrients. 2021 Mar 9;13(3):886.

2Donaldson DS, et al., The Gut-Associated Lymphoid Tissues in the Small Intestine, Not the Large Intestine, Play a Major Role in Oral Prion Disease Pathogenesis. J Virol. 2015 Sep;89(18):9532-47.

3Belkaid Y, et al., Role of the microbiota in immunity and inflammation. Cell. 2014 Mar 27;157(1):121-41.

4Zheng d, et. al., Interaction between microbiota and immunity in health and disease. Cell Research. 2020 May 20; 30, pages492–506.

5Leeuwendaal NK, et al., Fermented Foods, Health and the Gut Microbiome. Nutrients. 2022 Apr 6;14(7):1527.

6McFarland LV. Use of probiotics to correct dysbiosis of normal microbiota following disease or disruptive events: a systematic review. BMJ Open. 2014;4(8):e005047.

7Bishehsari F, et al., Alcohol and Gut-Derived Inflammation. Alcohol Res. 2017;38(2):163-171.

8Zhang W, et al., Understanding the Gastrointestinal Protective Effects of Polyphenols using Foodomics-Based Approaches. Front Immunol. 2021 Jul 2;12:671150.