The gut: your second brain
Should you listen to your gut? Scientists say yes. Many experts now refer to the intestines as the second brain – with good reason. In addition to its main task, digesting food components, your gut also influences your mental state by producing hormones. The intestines are in constant contact with the brain’s emotional control center via what is known as the gut-brain axis. Changes in the intestines can therefore have an influence on our emotional state. This goes both ways: our mood can also have an effect on intestinal activity. However, the flow of information from the brain to the intestine only accounts for an estimated 10% of the communication between the two organs. The other 90% flows in the opposite direction – from the gut to the brain.
The gut as the seat of happiness
The intestines produce important chemical messengers called neurotransmitters. These transmit signals from one neuron to the next, which in turn regulates our mood. In addition to dopamine, which boosts motivation, and gamma amino butyric acid (GABA), which has a calming effect, these include the “happiness hormone” serotonin, 95% of which is produced in the intestines. More specifically, certain cells of the intestinal mucosa first convert the amino acid L-tryptophan into the amino acid 5-hydroxytryptophan (5- HTP), which is then converted into serotonin. Serotonin plays a major role in stress tolerance. Sufficiently high levels have a positive effect on motivation and mood. Interestingly enough, serotonin not only plays a part in promoting happiness, it also stimulates the muscles of the intestines and thus ensures healthy digestion. Hormones are part of a highly complex system where the tiniest details are precisely coordinated. Imbalances in this system can lead to a number of consequences for both our digestives systems and our emotions.
“I have a gut feeling about this”
... or “I just can’t stomach it” – idioms such as these are firmly embedded in the way we speak; they testify to the close connection between the intestines and the brain’s emotional control center. Our intestines have a much stronger influence on our mood than previously assumed. The intestine is in fact extremely well connected. More than 100 million neurons are in intense communication with the intestinal bacteria – there is a lot of networking going on. These neurons branch off into neural connections that link them to the regions of the brain responsible for our emotions. All this goes to show just how important the intestine is for both our physical and mental health.
Stress – bad news for good gut bacteria
Our emotional state has a substantial influence on intestinal activity. The intestinal bacteria respond to anger, negative stress, psychological pressure and intense strain by gradually eliminating useful species. This creates an imbalance. It is quite astonishing how close the connection is between the mind and the gut: anxiety, for example, can speed up the gastrointestinal passage, and an emotional slump can slow it down.
Fostering good mind-gut relations
The composition of intestinal flora can help regulate our mental and emotional state – and vice versa. Sometimes it’s important to give our feel-good organ a helping hand. The best way to achieve this is through a balanced and varied diet rich in vitamins, minerals and fibre, which provides optimum support for the intestinal flora. “Food keeps the body and soul together”, as the saying goes. The intestinal flora should also be fed with plenty of bacteria – they help each other and ensure diverse colonization of the intestine.
Relaxation techniques, sports, exercise and an overall stress reduction can also help lighten the load on our intestines.
True to the motto: “A healthy mind for a healthy gut”.
