The more diverse and healthier the intestinal flora, the stronger the immune system. It is therefore worth supporting the bacteria in the intestine. And not just during the cold season.

The training camp of our defenses is in the gut. 70 to 80 percent of all immune cells that produce antibodies and fight infections or cancer cells in the body are stationed here in the submucosa. Submucosa means “under the layer of mucus”. The intestine is therefore a particularly important control center for the immune system.

Here the intestinal bacteria are in close contact with the immune cells. And the germs play a key role in making the immune cells strong to fight off infections. The constant confrontation with the microorganisms means that the body’s defenses are always alert. Therefore, it makes sense to take good care of the digestive tract and the intestinal flora if we want to strengthen our immune system.

Michaela Axt-Gadermann is a doctor and professor for health promotion in the “Integrative Health Promotion” course at Coburg University. She lives with her husband and children near Fulda. She has written numerous books on the subject of “intestines” and developed a licensed online nutrition coaching program (“Healthy with Intestines”) that is recognized by health insurance companies. You can find more information on the “Healthy with intestines” website.

Since the immune cells not only remain in the intestine, but also migrate through the body and visit other “defense stations” such as the lymph nodes, the immune information is passed on. In this way, a healthy and diverse microbiome can not only protect against gastrointestinal diseases, but also against numerous other infections.

Studies show that the immune system can even be specifically strengthened by taking probiotic bacteria.

“Healthy with intestines” by Michaela Axt-Gadermann

Probiotic microorganisms have been used for centuries to preserve foods such as sauerkraut, to brew beer or ferment milk and to make yoghurt or kefir. Lactic acid bacteria such as lactobacilli, bifidobacteria, steptococcus species, but also certain yeast fungi are often used for this purpose. Probiotic bacteria are not only considered harmless, they are also attributed numerous health-promoting effects.

As defined by the World Health Organization, probiotics are “live microorganisms that have a health benefit when administered in sufficient quantities”. We can supply these probiotic germs with food or also specifically with food supplements.

The effects that can be achieved with probiotics depend on both the dosage and the bacterial strains used. Probiotic bacteria are able to alleviate inflammation, strengthen the effectiveness of immune cells or even get a misguided immune system, as known from allergies or autoimmune diseases, back on the right path.

Studies show that groups of people who are considered particularly susceptible to infection – such as children, the elderly, competitive athletes, shift workers and people under stress – can benefit from a regular supply of beneficial bacteria. Children catch colds less often, have fewer fevers and coughs, and are less likely to develop gastrointestinal infections if they take probiotic bacteria for a few weeks.

For example, taking the probiotic bacteria L. plantarum and L. paracasei over a period of twelve weeks measurably reduced the risk of colds in Swedish preschool children. Among other things, the overall frequency of infections and the number of sick days decreased, and the symptoms were less pronounced. Children who received healthy bacteria for three months also required less medication than children who only took a placebo supplement.

Not only do wrinkles and gray hair increase over the years, the immune system also decreases over the course of life. This “immune senescence”, the aging of the immune system, can possibly be delayed by a healthy microbiome. The evaluation of the data from a total of over 700 healthy seniors showed, for example, that the activity of the killer cells increased significantly after taking probiotic bacteria for three to twelve weeks. Killer cells are immune cells that can attack and destroy pathogens and tumor cells, among other things.

US scientists came to a similar conclusion. They demonstrated that a probiotic mixture containing the bacterial strains B. bifidum, Streptococcus thermophilus, L. casei, L. reuteri and L. acidophilus could and was even able to specifically stimulate certain immune cells such as B and T lymphocytes was to reactivate down-regulated defenses. Smoldering inflammation went down. The conclusion of the study was that with the help of probiotics not only the immune system can be activated, but that they can also represent a potential therapeutic approach for inflammatory diseases.

Athletes benefit from probiotics in several ways. Studies have shown that susceptibility and duration of infection can be reduced during hard training or competitions and that inflammation can be alleviated. This affected both gastrointestinal complaints and infections of the upper respiratory tract such as a sore throat or a cold.

At the same time, the microbiome also seems to be responsible for around 20 percent of physical performance, as a Canadian study shows. Scientists from the University of British Columbia in Kelowna have shown that a diverse and species-rich intestinal flora is therefore a decisive factor for good endurance performance.

Probiotic bacteria could therefore represent a kind of “legal doping”. At least that is what a treadmill test under extreme conditions suggests. Well-trained competitive athletes lasted significantly longer in high temperatures and high humidity if they had previously received a dietary supplement with lactobacilli, bifidobacteria and streptococci for four weeks. Overall, the probiotic-supported athletes ran almost five minutes longer than the subjects who received a placebo.

Since the immune system needs some time to be activated, it makes sense not to wait until one infection follows the next, but to do something regularly for the microbiome.