What to Know About the Gut Health & Immune System Connection

With all of our scientific research in the last few decades on the role of the microbiome in health and disease, plus rising cases of autoimmune digestive disorders, it’s become apparent that the digestive and immune systems are inextricably connected.

In some ways, it seems like we’ve barely scratched the surface of this gut health and immune system link. We do have a solid grasp of some of the mechanisms that tie these two integral systems together in the body, however. One component that connects the health and integrity of both systems is the short-chain fatty acid butyrate. 

In this blog, we’ll discuss: 

Gut Health and the Immune System

To understand butyrate's role in protecting the immune system, we should first examine the immune system and gut connection. 

How much of your immune system is in your gut?

You’ve probably heard by now the astonishing statistic that at least 70-80% of our immune system is housed in the gut, in what’s called gut-associated lymphoid tissues, or GALT. And some 80% of plasma cells, mostly IgA-producing immune cells, also reside in these tissues. 

But, at a certain point, we’re splitting hairs here. The point is, a majority of your immune system lives in your gut, so taking care of your gut should be your biggest priority when optimizing and healing the immune system. 

How is the immune system related to the digestive system? 

The more you think about it, the more it makes sense that most of our immune system resides within the gut tissues. 

Our digestive system, after all, comes into the most contact with external stimuli of any system in the body (except possibly the skin, which is also very important to maintain!). These stimuli include microorganisms such as native gut bacteria, aka the microbiome, as well as food and the many nutrients that come from whatever we choose to consume. 

The GALT initiates immune responses depending on the microbial state of the gut, reacting when there are pathogens and toxins present. Sometimes it causes damage to the intestinal mucosa, as in celiac or inflammatory bowel disease. 

So, the state of our microbiome plays a huge role in how well our immune system can respond to invaders and toxins in the body. When we have enough of the good bacteria, not too much and not too little, our microbiome can effectively signal to the GALT when to initiate an immune response or signal to the colonocytes when to digest food or break down waste. 

How do the microbiome and immune system work together?

So, now we know that:

  1. A majority of the immune system resides in the gut.
  2. The immune system is integrated into the digestive system via the. gut-associated lymphoid tissue or GALT
  3. the GALT initiates an immune response based on the microorganisms, good or bad, that are present in the gut. 

This brings us to the role of the microbiome in the immune system. 

The microbiome is the composition of organisms in a person’s large intestine. (The small intestine should be mostly sterile.) These microorganisms carry out numerous functions, including breaking down nutrients, clearing toxins, and other vital functions. While certain strains of bacteria and fungi can be found in everyone’s microbiome, no two microbiomes have the same composition, even among identical twins. 

When you have a healthy microbiome, it works for you by performing its many functions — one of which is to create short-chain fatty acids (SCFAs), like butyrate, which go on to feed and support the GALT.

Short-Chain Fatty Acids for Gut Health and Immunity

What are short-chain fatty acids? 

Short-chain fatty acids, or SCFAs, are metabolites created by the microorganisms in our gut. There are several kinds of these SCFAs, including acetate, butyrate, and propionate. They all serve an important purpose in the gut, but we’ll be focusing mostly on butyrate.

How do short-chain fatty acids play into gut immunity? 

Short-chain fatty acids are critical to maintaining the structure and function of the gut lining, where the GALT lives—they are essential to our gut health and immunity. SCFAs provide energy for the cells of our colon, the selectively permeable gut lining. When our gut lining is strong, it only allows nutrients to pass through and blocks gut microbes and other unwanted particles from reaching the bloodstream and the rest of the body. 

Without SCFAs and a strong gut lining, we become predisposed to leaky gut, which then leads to further chronic inflammation and disease. 

SCFAs are only created by the microorganisms in the microbiome when those microorganisms feed off of certain resistant starches. Therefore, the main way we can regulate their production is by consuming more of these resistant starches and feeding the gut microbiome. 

How does butyrate support the immune system and digestive system?

Butyrate is one of these key SCFAs that support the colon and the gut lining. In particular, it’s a key factor in supporting a healthy inflammation response in the colon.

Butyrate on its own provides up to 90% of the energy required by the colonocytes, the cells of the colon! It’s no wonder a deficiency can lead to degradation of the gut lining and subsequent illness. When we have enough butyrate, we have a stronger gut, stronger GALT, and stronger immune response.

Butyrate also supports the mucosa that hydrates the gut lining, promotes cell differentiation, and inhibits enzymes that can interfere with DNA replication.

Who would benefit from having more butyrate in their gut?

Anyone who is experiencing digestive symptoms such as gas, bloating, constipation, diarrhea, and abdominal pain and discomfort may benefit from having more butyrate in their gut. However, every microbiome and body is unique, so you should consult with a trusted practitioner to determine what is right for you. 

  • Research on butyrate in clinical use has focused primarily on inflammatory bowel disorders, such as Ulcerative Colitis and Crohn's Disease, with favorable results.
  • Butyrate has also been found to have protective effects on brain health, including the potential for decreasing brain fog.*
  • SCFAs in general, including butyrate, have also been shown to affect cholesterol metabolism and increase mineral absorption, which is highly beneficial for heart health and circulation health.*
  • By supporting a healthy inflammation response, butyrate may be helpful for many other autoimmune and inflammatory conditions*

Two Ways to Increase Butyrate for Immune System Health

1. Eat butyrate-producing foods

As we mentioned earlier, butyrate and SCFA production only come from the food we ingest and the microbial balance in the gut available to break down that food into SCFAs. Most of the foods that allow our microbiome to produce SCFAs are resistant starches, and some of them aren’t the most appetizing. But, when you’re dealing with severe digestive issues or autoimmune diseases, you may find them worth adding to your diet. 

These foods include: 

  • Cooled cooked potatoes
  • Cooled cooked rice
  • Cold rolled oats
  • Legumes such as lentils and beans, when tolerated
  • Unripe bananas
  • Plantain flour
  • High-quality dairy, especially organic, grass-fed butter 

For more information, check out our blog: What Foods Can Help Increase Your Butyrate Levels? 

2. BodyBio’s Butyrate supplement

In addition to adding butyrate-producing foods, you may also consider butyrate supplementation. 

BodyBio Butyrate is formulated without extra additives or fillers to deliver the beneficial butyrate your gut craves without any junk.* Because it’s fermented, butyrate is well known for its smell, but this is a natural byproduct of the fermentation process—don’t worry! This is exactly how it’s supposed to be.

Butyric acid on its own is quite acidic, so we pair it with different minerals to raise the pH and stabilize it for delivery to the gut. We have created Calcium Magnesium and standard Sodium Butyrate varieties depending on your needs. Due to widespread calcium and magnesium deficiency, we recommend most people start with our Calcium Magnesium Butyrate

Dozens of folks have reviewed our butyrate saying that it helped ease their digestive problems and get back to a healthy, balanced gut.* 

Support Your Immune System with BodyBio

The immune system and the gut are intricately linked, with at least 70% of your immune system residing in the tissues of the gut lining. For these tissues to stay healthy and productive, they need fuel in the form of SCFAs. 

Among the SCFAs, butyrate especially has protective effects on the gut wall and intestinal function, helping in many cases to heal autoimmune reactions and improve overall health. 

Whether you incorporate more butyrate-producing foods or supplement butyrate, you are boosting and strengthening the connection between your digestive and immune systems for better health overall. Well done!

Looking for a supplement to improve gut health? Concerned your immune system is not as strong as it could be? Check out BodyBio’s Butyrate Supplements and our Butyrate/Gut+ Start Guide!

Medical Disclaimer: These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.


Wiertsema SP, van Bergenhenegouwen J, Garssen J, Knippels LMJ. 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. doi: 10.3390/nu13030886. PMID: 33803407; PMCID: PMC8001875.

Vighi G, Marcucci F, Sensi L, Di Cara G, Frati F. Allergy and the gastrointestinal system. Clin Exp Immunol. 2008 Sep;153 Suppl 1(Suppl 1):3-6. doi: 10.1111/j.1365-2249.2008.03713.x. PMID: 18721321; PMCID: PMC2515351.

Segain J, de la Blétière DR, Bourreille A, et alButyrate inhibits inflammatory responses through NFκB inhibition: implications for Crohn's diseaseGut 2000;47:397-403.

BÖHMIG, G.A., KRIEGER, P.-M., SÄEMANN, M.D., WENHARDT, C., POHANKA, E. and ZLABINGER, G.J. (1997), n-Butyrate downregulates the stimulatory function of peripheral blood-derived antigen-presenting cells: a potential mechanism for modulating T-cell responses by short-chain fatty acids. Immunology, 92: 234-243. https://doi.org/10.1046/j.1365-2567.1997.00337.x

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