How the gut affects our psyche
Everyone has one, no one mentions it: the gut. After all, he is responsible for digestion, and admittedly that's not always appetizing. But now it's time to throw all restraint overboard. Because new scientific findings show that the organ from the taboo zone is much more than a service provider who does the dirty work.
In the intestine, the immune system is at home. More than 70 percent of the body's own antibody factories are located there. In addition, the intestinal wall is crossed by a network of nerves that consists of many more cells than the spinal cord, which has earned the digestive tube the nickname "belly brain". And last but not least, there are hundreds of intestines in each intestine - experts estimate up to 1000 - different types of bacteria, a total of around 100 trillion, who work for us.
This microbiota (also called "microbiome" or colloquially "intestinal flora") is currently one of the most exciting research subjects in medicine. Because there is increasing evidence that it not only plays a major role in chronic intestinal inflammation, but also in the development of diseases such as cancer, diabetes, allergies and rheumatism. And that our intestinal flora could even regulate what we bring to balance and how confident we meet life.
Our intestinal flora influences our behavior.
"The hype around the gut right now is comparable to the euphoria involved in decoding the human genome," says Dr. Annett Braune, microbiologist at the German Institute for Nutrition Potsdam-Rehbrücke. By this she means not only the excitement about the subject and the hopes for new treatment options that are associated with it, but also the modern analysis methods, which are able to determine numerous types of bacteria at high speed and have made this development possible.
Looking at the amazing results of some experiments, the euphoria is understandable: For example, researchers have given antibiotics to mice of an anxious race that are destroying their intestinal flora. Then the animals behaved suddenly daring and enterprising. When the scientists transferred intestinal bacteria from a courageous mouse breed to timid animals (and vice versa), the character traits also changed hands. Even as a mouse in a desperate situation (in the experiment, this is a pool in which it can not stand) depends on their intestinal flora: If she previously fed certain gut-friendly lactobacilli (so-called probiotics), she gives her plan to Swim land not so fast and has less stress hormones in the blood than without the "good" microorganisms.
Are not listlessness, bad mood and a tendency to depression at the end not determined in the head, but in the gut? If confirmed, that would be a true paradigm shift, because so far no one has questioned the supremacy of the brain. Of course, one can not easily conclude from mice to humans. But no later than the study published in 2013 by Emeran Mayer at the University of California in Los Angeles suggests that this thesis could be a bit: The scientist had women regularly eat a probiotic yogurt for four weeks. It turned out that certain brain regions responded less favorably to negative stimuli than to subjects who ate normal yoghurt during this time or who had been feeding as before.
We all know that head and stomach are closely interlinked: we are "scared" of tests and butterflies in the stomach when we are in love. In case of difficult questions the gut feeling decides in case of doubt. Sadness spoils our appetite, and if we have not eaten for too long, the mood goes down.
How fast we feel well depends on our intestinal flora.
Responsible for this is, among other things, the vagus nerve, which works like a direct lead from the stomach into the brain. It runs through the diaphragm, along the esophagus, up through the neck and ensures that the head knows everything that the many nerve cells in the intestine report. Information arriving via this nerve in the brain is sometimes processed in regions responsible for emotions, in the so-called limbic system. This explains the close connection between head and stomach. And obviously also microbes use this line in the upper studio: Was turned off in the experiment with the floating mouse the Vagusnerv, the Laktobazillus intestine forum had no more positive effect.
But not only the microbiota sparks on the head - conversely, the head also influences the colonization in the digestive tract. "Stress changes the composition of the intestinal flora," says Professor Stephan Bischoff, a nutritionist at the University of Hohenheim.In a stressed gut other germs feel comfortable than in one, whose owner is completely relaxed. For example, a study from Australia showed that students in the exam phase have fewer of the desired lactobacilli than at the beginning of a semester.
Such changes could explain why many of us have caught cold so often during exhausting times. Because the intestinal flora provides the body's defense a kind of boot camp, in which this is constantly trained. And it stimulates the intestinal mucosa to form bactericidal proteins, which are proteins that cause pathogens. Meanwhile, studies have shown that taking fewer probiotics is less common, shorter, and less intense. The assumption that other infections can be prevented in this way is obvious. The antibodies are distributed from the intestinal mucosa through the vascular system throughout the body.
Does our intestinal flora also influence the eating behavior?
According to the latest findings, however, it may still be possible to influence something about the intestinal flora: body weight. Because it looks as if the microbiome is also responsible for the often ridiculed phenomenon of the "good feed processor". The fact is, intestinal bacteria help digest us by producing enzymes that break down long-chain ("complex") carbohydrates, such as fiber. Only then is the body's energy available.
The intestinal flora of Dicken, however, differs significantly from the slender people; she can eat more calories from food than thin ones. For them, every bite counts more. The effect is around 150 calories a day, according to a study by the US National Institute of Health. In mice, the recovered energy increased by about ten percent after the intestinal flora had been changed.
And that's not all. "The bacteria also affect the formation of hormones such as serotonin in the digestive tract," says nutritionist Bischoff. "The suspicion is obvious that in this way the eating behavior is modulated." Because serotonin makes you full and satisfied. How quiet someone can sit on the couch when there is half a bar of chocolate left in the kitchen could depend, among other things, on our intestinal dwellers.
To this day, the microbiota hardly plays a role in most GP surgeries.
Psyche, immune system, body weight and diseases: It is amazing not only what is controlled by the intestine, but also that of these relationships until a few years ago, no one has guessed. To date, the microbiota plays in the average family practice hardly a role, apart from the treatment of certain intestinal diseases. Too many antibiotics are still prescribed, although they are known to damage the intestinal flora by killing not only pathogenic but also numerous beneficial germs.
Naturopathic physicians have long been reluctant to prescribe such medications and recommend probiotic bacterial preparations following antibacterial clearcutting. Professor Jost Langhorst, Integrative Gastroenterologist (Specialist in Gastro-Intestinal Diseases) at the Essen-Mitte Hospital, is therefore pleased with the recent findings: "I am very pleased that the topic of microbiota now deserves the attention it deserves." In natural medicine, the intestinal flora has been taken into account for more than 100 years, says the expert. "And even in the Chinese healing arts much has been treated with the 'yellow soup'."
Yellow soup? This is a dilated stool of a healthy person who is given over the anus directly into the gut of the patient, including discomfort. As so-called stool transplantation, the procedure is just getting back on track. For certain severe diarrheal diseases, the cure rate is a spectacular 90 percent.
Basically, it does not matter to your body in what form gut-friendly bacteria such as lactobacilli or bifidobacteria are taken. In capsule or powder form, however, much more is needed than in a dairy product. The reason: The yoghurt matrix protects the bacteria from the attack of stomach acid, according to Professor Stephan Bischoff from the University of Hohenheim. Incidentally, useful bacteria are not only found in specially proclaimed probiotic yoghurts, but also in the others, as well as in kefir, buttermilk, sauerkraut and sour cucumbers. Since they do not settle in the intestine, they must be taken over a longer period of time. Probiotics are particularly useful after antibiotic therapy, irritable bowel syndrome, constipation and inflammatory bowel disease such as ulcerative colitis.
In addition, you can do your gut with so-called prebiotics good. These are ingredients in foods that stimulate the growth and activity of good gut bacteria. Particularly suitable are soluble fibers such as inulin (for example in Jerusalem artichoke or chicory, but also added in many foods) or fructooligosaccharides (also called oligofructose on yogurt cups). But do not eat three such yoghurts at once: if the bacteria decompose these substances, gases are created, which can be unpleasant. It is better to eat a lot of vegetables and plenty of whole grains.
Whether such recommendations will apply equally to women and men alike will have to be further investigated. As an international research team now found out, there are gender differences in the intestine: even if the same amount was eaten in the gut, this did not affect the female and male intestinal flora alike.
