Gut Health and the Immune System: How Are They Connected?

A strong gut barrier for the immune system

The gut is the largest internal organ of the human body and, with a total surface area of 30 to 40 square meters, also the largest interface with the outside world. It must absorb nutrients while fending off harmful substances. The former are consciously ingested through our food. The latter, such as bacteria, fungi, or heavy metals, are an inevitable evil against which our body has developed a sophisticated defense system. The gut barrier regulates which substances are allowed to enter the body and which are not. It consists of the following three protective layers:

• The gut microbiome
• The intestinal mucosa with its overlying mucus layer
• The gut-associated immune system

The microbiome encompasses all microorganisms living in the gut. These microorganisms prevent the colonization of harmful germs simply by being present. In addition, some bacteria produce short-chain fatty acids. These lower the pH into an acidic range in which many pathogens cannot multiply, thus preventing their spread.

The intestinal mucosa acts as a direct, physical barrier between the intestinal contents and the body's interior. Its cells selectively decide which substances are transported through the mucosa. The overlying mucus protects the mucosal cells from negative mechanical and chemical influences.

The gut-associated immune system (abbreviated GALT, from the English "gut associated lymphoid tissue") is located in the intestinal mucosa and contains about 70–80% of the body's immune cells. Its task is to fend off unwanted substances and prevent their entry into the body. At the same time, it prevents overreactions to harmless foreign substances that we ingest daily through our food.

Processing of vitamins and nutrients to support immune defense

Daily nutrition supplies our body with all the nutrients we need to maintain our metabolism. These are broken down during the digestive process and eventually absorbed through special mechanisms and transported via the bloodstream to target tissues.

The immune system relies on vitamin C, as well as trace elements zinc and selenium, to function. If the gut is weakened or impaired in its functions, this can affect the absorption of these immune-relevant nutrients. Digestive disorders are often associated with impaired immune function.

Colon and Small Intestine: What Roles Do They Play in Immune Defense?

The small intestine is the largest part of the intestine, measuring up to 5 meters in length. The immune cells of its mucosa serve to defend against viruses, bacteria, or parasites. The small intestine is composed of the following three sections:

1. Breakdown of carbohydrates and proteins into their individual components. Subsequent absorption along with fat.
2. Absorption of electrolytes, water, and other nutrients.
3. Absorption of vitamins and trace elements needed for immune function.

The colon: The main task of the colon is to extract water and salts from the remaining food residue, thereby thickening the stool. Another task is the breakdown of previously undigested fibers into short-chain fatty acids. These are necessary for maintaining the health of the intestinal mucosa. The bacteria are an important component of the intestinal barrier and thus indispensable for a functioning immune system.

How can the immune system be supported?

A healthy gut plays a key role in a functioning immune system. It is all the more important that you take care of it daily and give it the necessary attention.

Fiber is essential for healthy digestion. It stimulates the gut and acts like a workout for the intestinal wall. You should consume at least 30g daily. With our Fiber Vital Complex, you can cover 50% of this amount with ease.

Moreover, a healthy lifestyle supports the body's defenses: regular exercise, a plant-based diet, high-quality vegetable oils, and avoiding sugar- and fat-rich foods promote gut health and boost the power of immune cells. And if these guidelines can't always be followed, our Gut Concept gives your digestive system a well-deserved break and sustainably improves your gut feeling.