The intestine is rightly called the wellness organ. The Greek physician Hippocrates realized during his lifetime (300 BC) that a healthy intestine is the root of all health. After all, it performs numerous complex tasks in the human body – reacts to each of our moods, is a biochemical laboratory, guardian of the immune system, hormone factory, and habitat for a multitude of bacteria.
If the intestine is healthy, then we feel good. If it causes us problems, we feel listless, tired and exhausted. The influence of the intestinal microbiome on the state of mind is one of the most important findings of current scientific research.
Taboo topic – intestine and the influence on our psyche
It’s not like people like to talk about it. The intestine not only plays a central role in our immune system, it also directly influences our psyche through the formation of messenger substances. Whether someone reacts calmly and deliberately to stress or whether emotional stress immediately hits their stomach – the intestine is a highly sensitive organ, all our lifetime long.
Facts and figures about our intestines
With a length of approximately 8 meters and a surface area of approximately 200 – 400 m2, the intestine is one of the oldest organ systems in terms of developmental history. With its huge contact area, it creates the ideal conditions for effective absorption and utilization of nutrients. However, the intestine is by far not only responsible for the absorption of nutrients, but also for the formation of vitamins and the stimulation of intestinal peristalsis. It offers us a protective shield against harmful germs and strengthens our immune system – after all, it houses 70% of all defence cells. He also has a firm grip on the production of short-chain fatty acids such as acetic acid (acetate) and butyric acid (butyrate), which also determine the intestinal environment. Among other things, short-chain fatty acids serve as a source of energy for intestinal mucosa cells and are essential for maintaining the intestinal barrier.
Intestinal mucosa and intestinal microbioma = a functional unit.
The intestinal mucosa is very sensitive. It is protected from direct contact with the food mash by the microbial colonisation of the intestine – colloquially referred to as intestinal flora. If the intestinal flora is damaged, components of the intestinal contents can irritate the mucous membrane. This makes it more permeable to undesirable food components such as allergens or other potentially pathogenic germs, while at the same time disrupting the absorption of micronutrients. The body reacts with digestive problems such as diarrhoea, irritable bowel syndrome and increased susceptibility to infection and allergies. Stressors for the intestinal flora include an unhealthy and low-fibre diet as well as a lack of exercise and psychological stress such as stress or anxiety.
When the mood hits the intestines
Trusting one’s “gut feeling” or making decisions “from the gut”: Often ignored or misjudged. But neuroscience is now teaching us better, because the intestines and brain are much more interconnected than one would think. Our intestines actually work as a second brain – and quite independently. It has been proven that our intestines have an independently functioning nervous system that has many more nerve cells than our brain. The human intestinal microbiome is closely related to metabolic processes in the body and modulates psychological and emotional processes via the so-called microbial-intestine-brain axis. It is therefore not surprising that we often have the feeling that the abdomen has just as much influence on our decisions as our brain. A major advantage of gut feeling or intuition is that it reacts faster than the head can. Many will be familiar with phrases such as “butterflies in the stomach”. Our belly has brains!
95 % of the happiness hormone is produced in the intestine.
The intestine: Hormone factory de luxe. Our nerve cells in the digestive tract have the same structure as those in the brain. In purely evolutionary terms, both have the same origin. And that is why they both use the same messenger substances. First and foremost our well-being hormone serotonin, which is essential for cognitive functions. Our intestinal bacteria are significantly involved in the synthesis of serotonin. Other neurotransmitters and stress hormones are also closely related to the intestinal-brain axis: adrenaline, noradrenaline, dopamine, GABA, glutamate and cortisol. When the intestinal mucosa reacts like stress due to external influences, our intestinal inhabitants also react and disappear or die. Because stress activates the mast cells in the intestine and leads to an increase in the permeability of the intestinal barrier – this also applies to the blood-brain barrier. This allows antigens (food components, toxins, lipopolysaccharides, etc.) from the intestinal lumen to enter the blood and lymphatic system and trigger an immune response.
In order to positively support brain health, it is first and foremost necessary to strengthen the intestines. Intestinal bacteria are not only able to utilize the ingested food and to split indigestible substances. They synthesize vital vitamins and antimicrobial substances that inhibit the growth of pathogenic bacteria. They also have a positive effect on the intestinal epithelium and mucous membrane, the immune system and, last but not least, our mood. Studies show that lactobacilli and other intestinal bacteria influence the communication between the intestine and the brain. They can help to determine our emotional state and have a positive influence on our health and psyche. The formation of the neurotransmitter gamma-aminobutyric acid – also known as GABA – is influenced by strains such as Lactobacillus plantarum and Bifidobacterium adolescentis. GABA is one of the most important damping neurotransmitters in the brain and has a calming and anxiety-relieving effect.
Conclusion
The intestinal ecosystem is central to our health. The complex relationships between the intestinal microbiome and the human host influence not only the immune defence and metabolism, but also our emotional world. One could expect that we would give him the appropriate attention and care. All too often, the opposite is the case: it is important to pay more attention to the intestine and to value it more highly. The focus should be on a diet that is adapted to the intestines and consists as far as possible of varied, unprocessed, biological as well as domestic and plant foods. It is worth taking care of your well-being – every single day!
