Pain in the limbs that feels like it's tearing our bodies apart; feverish eyes that shy away from any source of light and a scratchy throat that makes even drinking tea a challenge - we all know the feeling of being ill. Our immune system is our invisible protector that protects us from these symptoms and many other illnesses. But if this doesn't work and we get sick, we try to get better with bed rest and medication: nasal sprays, paracetamol, hot lemon and chicken broth are among the usual remedies for counteracting an infection or flu.
We often neglect one of the most important parts of our immune system - our intestines. Almost everyone knows that they have an immune system that is important because it protects us from diseases or fights them. Many people do not yet know that the intestines are an essential part of our immune system and are indispensable in preventing diseases and in the body's own fight against diseases. For many people, the immune system is still an abstract concept because it is not as easy to visualize or understand as, for example, an organ. Most recently, microbiologist Giulia Enders also wrote poetry about the importance of the intestines in her poetry slam "Gut with Charm" and gave the hero of our immune system a voice.
In this article, we would like to explain what our intestines have to do with our immune system, where it is located in the intestines and how we can support the immune system in our intestines.
What does the gut have to do with the immune system?
Before we clarify what exactly the intestine has to do with our immune system, we would like to briefly clarify what the immune system actually is.
Our immune system is our body's defense system and it fights harmful pathogens and cells so that we do not become ill but stay healthy.
The immune system is a complex network that consists of various actors that act within it: several organs, numerous messenger substances and various cell types are part of our immune system, including our intestines.
Even though we were born with a gut and it could therefore be considered part of the nonspecific (innate) immune system, the gut-specific immune system is part of the specific (learned) immune system.
This is because it is only built up and developed through external influences and through confrontation with our environment and its pathogens after birth and throughout life. When our intestines come into contact with a potential pathogen, such as a virus or bacteria, our body uses certain defense mechanisms to specifically ward off and fight the pathogen. Our immune system basically remembers the properties of the pathogen and can then fight it off even more effectively on further contact.
For a long time, the intestine was only assigned the role of a digestive organ, but we now know that around 70 percent of our defense cells are located in the intestinal wall. The intestine has more defense cells than our skin and respiratory tract combined. If our intestine is weakened, our immune system is also weakened. People with autoimmune diseases therefore often have chronic intestinal problems. In addition, our intestine is in constant contact with the brain via the gut-brain axis, which is why it is also referred to as our "second" brain.
For all these reasons, the intestine is now considered the seat of health. The gut's own immune system even has its own name: GALT.
GALT – Gut-Associated Lymphoid Tissue
The GALT is now considered the main player in our immune system. The immune system of the intestine can be divided into three barriers: the intestinal mucosa, the microbiome (“intestinal flora”), and the gut-associated immune system (GALT).
The so-called gut-associated lymphatic tissue is a secondary lymphatic organ that is attached to the intestinal system and provides local immunity there. The GALT consists of the tonsils, Peyer's patches and intraepithelial lymphocytes. The GALT works closely with the microbiome (intestinal flora), which is why we would like to first focus on the intestinal bacteria before taking a closer look at how the GALT works.
Which intestinal bacteria for the immune system?
Bacteria in our intestines? That doesn't sound good, some people might think. The truth is, however, that our intestinal flora, which consists of countless bacteria, trains our immune system and keeps it up to date. But what exactly is intestinal flora?
Our intestinal flora includes around 39 trillion intestinal bacteria, of which over 1000 different bacterial species have been identified. The highest density of bacteria is found in our large intestine. These bacteria break down indigestible fiber, they produce energy, fatty acids, gases and they manufacture certain vitamins. They also break down toxins and train our immune system. However, we not only have good and health-promoting bacteria in our intestines, but also "bad" bacteria, the putrefactive coli bacteria. Coli bacteria are there to break down proteins, producing toxic substances that are responsible for the rather unpleasant smell of feces. Incidentally, the less odorous your stool, urine and sweat are, the healthier and cleaner our digestion is.
Good bacteria for our intestines include lactobacilli and bifidobacteria, which are the counterpart to coliform bacteria and keep our intestines in balance. Lactobacilli produce lactic acid, which ensures a healthy intestinal flora and a more efficient supply of nutrients and vital substances.
Lactobacillus Plantarum, Bifidobacterium Lactis and Streptococcus Thermophilus are examples of good gut bacteria that strengthen the immune system and intestinal health.
Where is the immune system located in the intestine?
We have already learned that the immune system in the intestine is also called GALT and that the GALT works closely with the intestinal flora. The complexity and great challenge for the GALT is not only to locate pathogens, viruses and bacteria after they have passed through the intestinal mucosa, but also to recognize and allow the beneficial nutrients and microorganisms to pass through. But where is this GALT located in the body?
The gut-specific immune system is located in the intestinal mucosa. It works in harmony with our intestinal flora and the intestinal mucosa in a kind of lock system so that our intestines can fight off pathogens.
Here, one can imagine that the intestinal flora is the “guardian” that decides which substances are allowed to pass through the lock.
These substances, approved by the intestinal flora, then reach the intestinal mucosa, which transports the substances through tight junctions into the intestinal mucosa, where they are further processed by the body.
This is where the GALT comes into play, which checks whether all the substances, bacteria, etc. that have been introduced are actually “good” and beneficial to health. If a virus or harmful bacteria has made it here, the GALT removes it from circulation.
Build up intestinal flora for a better immune system
If you want to strengthen and care for your intestines and your gut-specific immune system, there are two strategies you can pursue. Either you directly consume good intestinal bacteria, i.e. probiotic bacterial cultures, or you feed the good bacteria in the intestines with fiber.
1. Probiotic bacterial cultures
It is recommended to ingest lactic acid bacteria (probiotics) directly. This can be done, for example, through probiotic bacterial cultures such as Lactobacillus Plantarum, Bifidobacterium Lactis or Streptococcus Thermophilus, which are available in capsule form.
The probiotic Bifidobacterium Bifidum, for example, helps maintain a healthy intestinal flora and strengthens the immune system. The intact state of the intestinal microbiome has a positive influence on digestion, metabolism, body weight, the immune system, appetite and general well-being.
With Swiss Immune® we have developed one of the most powerful, natural Swiss raw materials, colostrum, to support the immune system. The antibodies (immunoglobulins) contained in colostrum and the numerous other nutrients support both our specific and non-specific immune systems throughout our lives.
As we age, our immune system becomes less efficient and will therefore gratefully accept a supply of immunoglobulins and other valuable nutrients. Especially in stressful times or after illness, adjusting our diet and taking additional immunoglobulins in the form of colostrum can help us to feel generally well.
2. Feed good intestinal bacteria
Our good intestinal bacteria love soluble fiber, such as that found in porridge . Warm and fiber-rich meals, such as porridge, also relieve the immune system because the energy can be used more efficiently, as the meal has been pre-digested by the heat.
The health-promoting intestinal inhabitants feed on these fibers and can multiply, which has a beneficial effect on our intestinal flora and thus also on our immune system. Cooked, cold potatoes also offer our intestinal bacteria an excellent meal to strengthen them and support their multiplication.
Credentials:
https://www.spektrum.de/lexikon/biologie/galt/26440
https://www.spektrum.de/lexikon/biologie/darm/16803