Stress, cold, wet weather and the spread of infectious bacteria and viruses put the immune system to the test. Strong defenses are therefore particularly important in challenging times. But how does the immune system actually work in the human organism?

You can imagine the immune system as a network of sentries communicating with each other in all possible places in the body. There is our skin with its acid mantle and the mucous membranes. These represent the first solid barrier for pathogens from outside. For example, there are mucous membranes with cilia everywhere in the respiratory tract and the gastrointestinal tract.

If something that is considered a nuisance enters, these membranes form a film of mucus to flush the pathogen out of the organism, for example through a cold. If the immune system is not successful in this, it activates another form of protection: phagocytes from the lymphatic system and white blood cells attack the foreign bacteria, viruses or fungi to render them harmless. This is also referred to as the "non-specific immune defense."

If this is also unsuccessful, the "specific immune defense" kicks in. This refers to the lymphocytes, a subgroup of white blood cells (leukocytes). They are "imprinted" in the bone marrow, spleen, thymus and lymph nodes, which means that they "learn" there which substances belong to the organism and which do not. While the non-specific defense is innate, the specific immune defense is based on previous contact with pathogens, which are now immediately recognized as harmful and fought.

The immune system is actually capable of learning and can be trained. On the one hand, it learns from each infection it overcomes how to protect itself against the same pathogen in the future. On the other hand, we can train our body to produce heat more quickly when necessary by taking alternating showers, using cold water and getting enough exercise. In fact, regulating the body temperature is an important way of fighting pathogens, in more serious cases also through fever. This also fits in with the fact that many viruses and bacteria are less active in the summer months than in the cold, wet winter months.

You can do a lot for your immune system. A balanced and nutrient-rich diet is particularly important, as our immune system depends on a sufficient supply of essential vitamins and minerals. Food supplements that contain immune substances such as vitamin C and vitamin D, which are essential for a functioning immune system, as well as antioxidants in precise doses can also be helpful. Look for combinations, for example in the form of capsules with sea buckthorn, echinacea, vitamin C, vitamin D, vitamin E and selenium.

In addition, you should make an effort to reduce negative stress, get enough sleep, get plenty of sunlight, and exercise regularly – or otherwise make your body sweat.

The intestinal flora also plays an important role in maintaining a strong immune system. If this becomes unbalanced, it usually has adverse effects on the body's own defenses. So make sure you eat a diet that is healthy for your intestines and only take antibiotics if there is absolutely no other option.