Attention - now it’s getting philosophical: Aren’t we all basically searching for happiness and joy? Throughout our entire lives, we wish for just one thing: to be happy. Whether we ever achieve the state of complete happiness is, of course, very questionable and depends on a variety of factors in life. Unfortunately, most of it is not in our hands. Well, somehow we can still influence our mood and satisfaction. As the saying goes, “Everyone is the architect of their own happiness.” There is a substance in the human body responsible for joy that we can indeed influence. Allow us to introduce – the happiness hormone serotonin.
Serotonin brings us into balance
What exactly is this little “bringer of happiness” in our body and where does it act? Serotonin is both a hormone and a neurotransmitter that regulates numerous bodily processes. Its most well-known effect is in the brain, where serotonin acts as a neurotransmitter in the human control center. It functions like a messenger traveling through our nervous system, passing information from one nerve cell to the next. To a certain extent, serotonin ensures that all information processes in the brain – and there are quite a few – run correctly. If there is too little of the hormone in the body, these information processes can become unbalanced, affecting the entire organism and impacting our mood.
However, serotonin is not only found in the brain and nervous system but also in blood platelets – thrombocytes – as well as in large amounts in special cells of our gastrointestinal tract.
The happiness hormone
The serotonin level plays an important role in one’s well-being and influences both physical and psychological mood. Serotonin is also known as the “feel-good hormone” and not only brightens mood but can also dampen the body’s stress response. Serotonin is a true all-rounder when it comes to mood, as it can also have relaxing, antidepressant, sleep-promoting, pain-relieving, and motivation-enhancing effects.
The majority of serotonin is produced in the so-called enterochromaffin cells in the gut. These cells are located in the epithelial tissue of the digestive tract, the layer lining the inside of the small intestine. The happiness hormone doesn’t just appear out of nowhere – it is formed from the amino acid tryptophan. Special enzymes attach a hydroxyl group to tryptophan and remove a carboxyl group, releasing carbon dioxide – hence the biochemical name 5-hydroxytryptamine. The finished serotonin is then stored in small storage compartments called vesicles and released as needed. Once released, serotonin is reabsorbed via a 5-HT transporter and either returned to the storage vesicles or broken down. This breakdown is carried out by various enzymes, such as monoamine oxidase A (MAO-A). The end product of serotonin breakdown is called 5-hydroxyindoleacetic acid, which is then excreted in the urine.
The happiness hormone works, like most other messengers in the body, by binding to specific receptors. In fact, there are more than 14 different receptors to which serotonin can bind. These are also called 5-HT receptors.
The role of the gut
It is known that a well-regulated serotonin level is not only important for the brain and mood but also influences other areas of well-being. Since serotonin is produced not only in the brain but also gut bacteria are capable of synthesizing the neurotransmitter GABA (GABA receptors play an important role during the development of neuronal structures in the brain) as well as the serotonin precursor L-tryptophan, a poor colonization of the gut by good bacteria may prevent sufficient L-tryptophan and GABA synthesis. However, if enough “good” bacteria (meaning good, tryptophan-producing bacteria) are present, more L-tryptophan and thus more serotonin can be produced. This results in positive effects such as better overall well-being.
The effect of serotonin
As already explained, serotonin can dock onto various receptors on the surface of different cells. Each serotonin receptor triggers a different reaction in the organism. Therefore, serotonin controls many different processes in the body. When considering the influence of the happiness hormone on the central nervous system, the messenger affects body temperature, appetite, various emotions, and the central reward system. But that’s not all. Serotonin influences your mood and drive, your state of consciousness, the sleep-wake cycle, and pain perception in the body.
Since the happiness hormone is not only found in the brain, serotonin also affects other areas of our body. For example, it can change the diameter of blood vessels, bronchi, and the gut. Additionally, the neurotransmitter stimulates blood platelets (thrombocytes) and thus plays an important role in blood clotting.
Boosting serotonin levels
Serotonin makes you feel good – so the question arises: how can you influence the production of this bringer of happiness? The messenger is produced by the body itself, and there are several ways to ensure serotonin is released. Whether amino acids, minerals, or vitamins, there are numerous ways to positively influence serotonin levels naturally. Since about 80% of serotonin is produced in the gut, it is logically important that it is healthy to produce the hormone. That’s why many health-conscious people turn to prebiotics and probiotics – also called synbiotics – to ensure the gut microbiome is intact. Fermented foods like kimchi or sauerkraut also contain probiotics and are very healthy for the gut. Additionally, various vitamins and minerals can influence serotonin production. This is because they are additional components the body needs to synthesize the hormone. Some are even directly involved in serotonin formation. Since serotonin is formed from certain amino acids, these should be supplied sufficiently through a good diet. This especially includes the amino acid tryptophan, found in foods like nuts or fish. Tryptophan is first converted in the body into the intermediate 5-HTP and later into serotonin in the brain.
Measuring serotonin levels
As you have just learned, the happiness hormone is involved in several areas of the body. Therefore, a serotonin deficiency can negatively affect the entire organism and lead to unpleasant symptoms. It is thus sometimes advisable to investigate this further.
Are you often sad for no reason? Do you experience depressive moods, anxiety disorders, or lack of drive? Then it might be time to measure your serotonin levels. Don’t worry, it’s very easy and super uncomplicated. Nowadays, the test can even be done at home. You just need to order a test kit, provide a urine sample, and send it to a lab. A few days later, you should have your results. Then it will become clear whether your current mood is related to a serotonin deficiency. If not, you should definitely seek further medical help.
Of course, you can also consult your general practitioner about this topic from the start if you feel more comfortable. Usually, they check your serotonin level with a blood test. Unfortunately, these tests cannot yet provide 100% certainty about your serotonin level because they cannot measure the value in the brain.
A serotonin deficiency can also manifest elsewhere, as it can affect the entire body. A lack of this happiness hormone can result in headaches or muscle pain, reduced feelings of satiety, concentration problems, or sleep disorders. Other symptoms include irritable bowel syndrome, high blood pressure, and various cardiovascular diseases.
Summary of serotonin
Serotonin functions in the human body as both a hormone and neurotransmitter. It is formed from the amino acid L-tryptophan. The good news is that this amino acid can be obtained through various foods and supplements. Serotonin is a true “bringer of happiness” and can positively affect mood and well-being. It also has a calming effect and can reduce stress perception! But that’s not all, as it can improve memory performance and promote good sleep. If you have too little of the happiness hormone in your body, it can lead to bad moods, anxiety, and aggression.
Ultimately, if your serotonin level is in order, you feel good and comfortable!
Learn more about serotonin and the gut in episode 59 of the Matcha Mornings podcast, where our co-founder Dr. Adrian Weingart was a guest.
