In our language, the relationship between the stomach and the head has long been manifested. Science, on the other hand, has only been studying how intestinal health affects our brain for a few years. The microbiome and its effect on our well-being and our mental abilities play a decisive role. Is it possible, for example, to increase mental performance through intestinal health? We have put together the scientific facts for you.
How important is a healthy bowel?
A healthy intestine is essential for optimal nutrient utilization. Thus, gut health is indirectly involved in the functions of all other organs. The intestine fulfills a special function in shaping the immune system and it probably even influences our psyche. Read on for more tips on strengthen your immune system want to know.
You can clearly see how important the intestine is by its autonomy. In contrast to all other organs, the control of the intestine is not dependent on the brain. The control center of the intestine is located in the intestine itself. More precisely, a plexus of nerves encloses the entire intestinal walls like a network. This plexus of nerves is known colloquially as the intestinal brain or the abdominal brain. A bowel still works when it is isolated from the body. The designation of the intestine as the second brain or the talk of the intestinal brain is therefore no coincidence. Nevertheless, the gut and the brain communicate with one another. The so-called gut-brain axis communicates in both directions, with more information being sent from the gut to the brain than vice versa. The information is passed on either directly via nerve tracts and neurotransmitters or via released hormones.
However, many tasks are not performed by the intestine itself, but by the bacteria that live in it. The intestinal bacteria are therefore moving more and more into the focus of science.
What is the gut microbiome?
The intestinal microbiome describes the entirety of the genes that the intestinal microorganisms possess. In contrast, medical professionals summarize all intestinal microorganisms as such as intestinal microbiota. However, the term microbiome often refers to the intestinal microbiota and thus simply the intestinal flora.
100 trillion microorganisms colonize your intestines. There are more single cells than your entire body has in its own cells. So it is not surprising that microorganisms have such a great impact on us. Researchers estimate that there are over 1000 different types of germs in our intestines.
How do gut bacteria control your health?
The intestinal bacteria break down food for us that we cannot digest ourselves. They provide us with important metabolic products and break down toxins. They also protect us from pathogens and help regenerate the intestinal mucosa.
Some experts therefore even refer to the microbiome as an organ. A dynamic balance of the intestinal flora is crucial for smooth functioning. Nobody knows yet whether it depends on individual types of bacteria or on the diversity of as different bacterial strains as possible. Scientists have already been able to detect differences in the microbiome in patients with a wide variety of diseases. From bowel diseases to autoimmune diseases and neurodegenerative diseases, everything is the subject of microbiome research. However, it has not yet been clarified whether an unbalanced intestinal flora causes the disease or whether the altered intestinal flora is caused by the disease.
How does the gut affect the brain?
The intestine constantly transmits information about its condition and metabolism to the brain. Much information is directed into the emotional center of the brain, which could explain the gut feeling. The microbiome also produces messenger substances that affect the brain.
After the brain, the intestinal nerve plexus is the second largest neural agglomeration in our body. Accordingly, both nerve centers have some things in common. They both develop from the same embryonic tissue and use the same messenger substances for communication. These neurotransmitters include dopamine, Gamma-aminobutyric acid (GABA) and serotonin. Hence, it is not surprising that the two nerve centers interact with each other.
How does the gut affect your neurotransmitter balance?
The nerve cells of the intestine communicate with one another just like the neurons of the brain by means of neurotransmitters. But the bacteria also release neurotransmitters and in this way react with the intestinal brain and perhaps even with the head-brain via the bloodstream.
According to studies, the bacteria in the intestine can change the neurotransmitter balance.1, 2, 3 For example, researchers have already been able to demonstrate the effect of the microbiome on the serotonin concentration in the blood in animal experiments.1 Germ-free mice have a lower serotonin level, which can be increased by the transfer of intestinal bacteria. After antibiotic treatment of mice with a natural microbiome, the serotonin concentration also decreased. Depending on the microbiome, scientists could observe fearful or more courageous behavior in their test animals. A pronounced serotonin deficiency can be responsible for anxiety and depression. The investigation of the neurotransmitter balance actually revealed changes in serotonin concentrationen on.2, 3
Like yours Increase serotonin levels you can read here at the Academy.
Serotonin isn't the only neurotransmitter that bacteria seem to have an impact on, however. So other types of bacteria are known to produce GABA. According to scientists, the released GABA molecules could have an anxiety-relieving and calming effect via the vagus nerve.4
Studies in which mice were given very strong antibiotics provide further indications of intervention in the neurotransmitter household. After the intestinal flora died off, the mice showed cognitive impairments in comparison to untreated mice.5, 6 However, it is not clear whether changes in the neurotransmitter balance were directly responsible for the cognitive losses. An indirect effect via molecules of signal transmission or via the intestinal-brain, whose signals to the head-brain influence the neurotransmitter concentrations, is also conceivable.
How does your mental performance benefit from a healthy bowel?
Colonization with the right intestinal flora could strengthen your memory, improve your learning skills and increase your mood. There is even hope that improved bowel health could alleviate depression and anxiety. Much scientific evidence suggests a strong link between gut health and a well-functioning brain. However, this has not yet been clearly proven and explained.
What can science do now?
The enormous number of studies and the steadily increasing interest of researchers reveal the potential of the microbiome and the intestinal brain. Various studies already show astonishing effects of the intestinal flora on cognitive processes and the psyche. However, more extensive studies with data from humans and their reproducibility are still lacking for unequivocal proof.
This is what studies about the microbiome and cognitive processes say
Several studies indicate that, especially in stressful situations, a well-positioned intestinal flora is necessary for optimal cognitive processes such as memory and learning.7, 8, 9, 10, 11 The intestinal flora must therefore be in a certain balance. For example, certain bacteria were able to reduce the memory performance and learning ability of mice in one study.12
The scientific situation on the relationship between the microbiome and behavior
Studies have also shown that the microbiome is said to influence behavior and mood.11, 13, 14 Researchers have transplanted the microbiome of quite fearless mice into other mice that have behaved rather reluctantly. After the transplant, the initially frightened mice behaved noticeably more curious.15 Scientists were also able to demonstrate in mice that certain lactic acid bacteria can regulate the formation of GABA receptors differently in different brain regions. These mice behaved more fearlessly and had fewer stress markers.4 Even autistic behaviors could be caused by the microbiome. After researchers normalized the microbiome of mice with some type of autistic behavior pattern, they observed less autistic traits in the mice.16
Research on gut health and psyche
Studies on healthy people also provide evidence that fermented milk products have an impact on our brain and psyche. The bacteria it contains can change the activity of brain regions that are responsible for processing feelings and sensory impressions or that have positive effects on the psyche.17, 18
In countries where a diet high in fermented foods is common, depression is less common. This finding supports the assumptions made by scientists with regard to the effect of the intestine on our psyche. However, in this case it has not been proven whether the lower risk of depression is due to an altered intestinal flora.
In addition to the intestinal flora, the direct connection between the intestine and brain via the vagus nerve also seems to play a major role. Above all, the limbic system that processes feelings should be the focus. Scientists have severed the nerve pathways in mice that the intestines use to send information to the brain. The animals were then significantly less anxious.19
Another theory involves communication between gut bacteria and the gut brain. According to this, some intestinal nerve cells only react when certain bacteria are present. This should also be noticeable in behavior and have an anxiety-relieving effect.20
There are many indications that in the future the treatment of a mental illness will be supplemented by microbiome counseling in addition to conventional therapy. Aside from the promising approaches to new treatment options, it is almost a bit scary when our behavior is so extensively determined by bacteria.
Probiotics and Gut Health - What Can You Do For Your Gut Health?
Your diet affects your microbiome and therefore your gut health. In addition, certain probiotics and prebiotics can help your intestinal flora to stay in the right balance. You can also incorporate prebiotic or probiotic foods into your nutrition plan or provide targeted help with dietary supplements.
What is the difference between probiotics and prebiotics?
Probiotics contain live bacteria that are supposed to settle in the intestines. Prebiotics are mostly indigestible fiber that stimulates certain beneficial types of bacteria to grow. Taking an antibiotic can upset the intestinal flora. Many therefore swear by probiotics or prebiotics to rebuild the intestinal flora destroyed by the antibiotic.
In some studies, researchers have also found positive effects in healthy people with probiotics or prebiotics.17, 18 Therefore, it could be worthwhile to optimize your own intestinal flora. You may be able to maximize your mental performance and at the same time ensure more balance in your brain. Science is well on its way to finding explanations and undisputed evidence for it.11, 21
Which foods ensure a good intestinal flora?
A diet rich in fiber not only stimulates the intestinal activity by irritating the intestinal walls, but also increases the microbial diversity in the intestine. Fermented foods such as sauerkraut and yoghurt, on the other hand, have a probiotic effect on the intestinal flora.
Besides sauerkraut and yogurt, other lactic-acid foods like kefir, kimchi, and buttermilk are also rich in beneficial bacteria. Above all, bifidobacteria and lactobacilli ensure the probiotic effect. It is very important that these foods have not been overheated. After all, the bacteria must arrive alive in your intestines in order to settle there.
You can find prebiotic substances in many vegetables such as chicory, artichokes and Jerusalem artichokes. Bananas and whole grains are also rich in prebiotic fiber. These include inulin, oligofructose and lactulose in particular. They can be used very well by the beneficial intestinal bacteria, so that they multiply and expel harmful bacteria.
The composition of the intestinal flora changes only slowly when you change your diet. The bacteria themselves can change within a few days and adapt their metabolism to a new diet. This creates other metabolic products, which in turn can affect your body and your well-being.
What role do dietary supplements play in gut health?
Probiotics and prebiotics are available as dietary supplements and can be used according to individual needs. They are available as capsules, powder, tablets or in the form of drops. Some manufacturers offer probiotics and prebiotics mixed in one product.
The amount of natural probiotics and prebiotics that you need to eat each day for any noticeable effect could be an issue. The much simpler solution is to take the concentrated amounts as a dietary supplement. In addition, as probiotics, dietary supplements have another decisive advantage. Packed in a capsule, the bacteria can more easily survive the route via the stomach and enter the intestine alive.
Even with the other dosage forms, the survival of the bacteria is more likely, since the concentration is higher than in natural probiotics. You can also choose supplements with certain types of bacteria that perfectly complement your individual intestinal flora. Because only a third of the microbiome is similar in all healthy people. The other two thirds are about as personal as the fingerprint.
How can you test your intestinal flora?
Some doctors offer an intestinal flora analysis in their range of services, the costs of which you usually have to bear yourself. Alternatively, you can order a test at home independently of the doctor and send your stool sample yourself to an appropriate laboratory.
The only differences are the evaluation of the test and the price. A visit to the doctor has the advantage that you have a direct contact person for questions about the interpretation of findings. You can also benefit from the experience of a good doctor. They can better assess your individual situation and advise you on your expectations. If you still want to avoid a doctor's visit, we recommend a test with the most extensive possible interpretation of the findings.