Immunity in the Gut

Immunity – professionally called the immune system – is the cooperation (collective agreement) of many organs, thanks to which our body creates defense mechanisms against internal threats such as diseases, toxins and cancer cells. Immunity is also a defense against external enemies: viruses, bacteria, fungi and parasites.

Main goal of this article is to indicate the important role of intestines and their content in the creation and functioning of immunity.

We divide resistance into two systems.

Innate immune system (non-specific) includes, among other things: mucus, sweat, gastric acid ph, digestive enzymes, saliva and tears. To a large extent we get genetic immunity from our mothers – a set of ready antibodies and the core of bacterial microbiom.

Adaptive immune system (specific) which is a liquid army or leukocytes and the organs of their production. The organs for lymphocytopoiesis (leukocyte production) are scattered throughout the body. Production of leukocytes takes place in the bone marrow, thymus, lymph nodes, spleen and, most importantly, in the GALT – gut-associated lymphoid tissue.

From this place you can enter an infinitely long journey through the human body and defense mechanisms, but let’s focus only on the digestive tract, where GALT is located. Lymphatic tissue, associated with the mucous membranes of the small intestine, forms clusters called Peyer’s Tufts.

Peyer’s tufts which produce immune cells that can resist the pathogens attacking us. We’ll find a whole range of white blood cells there, which gain immunological memory – they learn to recognize threats and prepare for effective fight against pathogens. Peyer’s tufts are found in the small intestine, appendix and colon. An interesting element of their epithelium are quite important M cells (microfold cells). These M cells are the “door” for antigens (macromolecules, bacteria, viruses and parasites) which wanders through the intestine. Antigens are “invited” and let in to a palce filled with different types of cells related to the immune system. There, T and B lymphocytes, dendritic cells and macrophages effectively recognize, learn to fight and pass information to the rest of the body about their discovery and how to fight the “enemy”.

If everything works fine, our body can effectively defend against various types of pathogens. The problem begins when the work of the intestines and their three protective layers (probiotic bacteria, mucus and intestinal epithelium) is disturbed. Instead of preparing for various challenges, the immune system uses its potential to try to repair something that is destroyed by bad habits, inadequate diet, stress and pharmacology. Persistent intestinal dysbiosis leads to a situation where about 70% of the immune system is occupied. It is no wonder that the effectiveness of our body’s protection drops significantly. By caring for our intestines through a proper diet, probiotics and lifestyle, we have a huge impact on the condition of our immunity. Immunity in our intestines works not only thanks to Peyer’s tufts. The right composition of the intestinal microflora has an impact on the production of very valuable mucus, which protects us against adherence of pathogens to receptors on the intestinal epithelium’s  Surface. Appropriate bacterial strains are also direct fighters e.g. against some types of viruses. Not only the structure of the intestines, but also their composition is a very important element.