Blue all the time?:Serotonin and the Gut-Brain Axis
Feeling blue? Having low mood and sadness are normal responses to difficult situations, those that move something inside us. But what happens when this sensation persists over time? This human experience is linked to an imbalance in the complex neurochemical network in our bodies, particularly involving the neurotransmitter serotonin and the Gut-Brain Axis. For that reason, today, we will talk about: why we feel blue, the role of the multifaceted serotonin and how the gut-brain connection works. Let’s have a closer look…
What Is Serotonin?
Serotonin(link1)( 5-hydroxytryptamine (5-HT)) is a neurotransmitter found throughout your brain. It has a pivotal influence in your:
- mood
- emotion (fear)
- sleep patterns
- appetite
- digestion
- cognitive functions (memory, focus)
- stress response
- sexuality
- addictions
- breathing
- body temperature
Why is serotonin so important for mental health?
Serotonin is your natural mood booster, when hormone levels are balanced and enough, you feel calm, focused, and happy. On the other hand, low levels of it are strongly linked to depression and feelings of deep sadness (“feeling blue”). On the contrary, too high levels of serotonin gives you that sensation of Euphoria.
Why do we feel blue all the time?
This persistent “blue sensation- feel blue”, with no apparent reason, can arise from serotonin imbalances in your brain, affecting mood regulation, stress response, and your cognitive functions (focus, memory, etc.). Factors that influence these imbalances include: genetic predisposition, environmental stressors, diet, and gut microbiome composition (because your gut produces more serotonin than your brain).
When serotonin signaling is disrupted, brain circuits involved in emotion and motivation are affected, leading to symptoms of depression or anxiety. For that reason, enhancing serotonin level is the main target in depression or trauma treatment.
Serotonin outside my brain?: How is it possible?
It might surprise you, but about 90% of our body’s serotonin is produced in the gut; yes, our intestines produce the majority of the happy hormone! Actually, serotonin is produced by specialised cells called enterochromaffin in the intestinal mucosa thanks to the help of microbiota (good bacteria in your intestinal tract).
This gut-derived serotonin directly influences appetite and digestion, but does not cross the blood-brain barrier directly. Despite this division in production, your gut’s serotonin plays a crucial role influencing brain function and mood.
How can the brain and gut communicate?: The Gut-Brain Axis
Your gut and brain communicate through a bidirectional system known as the gut-brain axis. This system links the enteric system (nerves in the wall of your gastrointestinal tract), the vagal nerves (part of the autonomic nervous system, connecting CNS and organs) and the central nervous system (CNS brain-spinal cord). This network also includes endocrine, humoral, metabolic, and immune routes.
How does gut serotonin affect your mood and cognitive function?
The serotonin produced in your gut interacts with the 5-HT receptors (serotonin from the brain) on vagal nerves, then, the signals are sent through the vagus nerve to the brainstem and are received in different brain regions influencing mood, cognitive function, mental health and your general well being.
How can I support my serotonin production?
As we mentioned before the majority of your serotonin is produced in the gut, so when your intestines are full of good bacteria and these organisms are well fed your serotonin levels will be balanced.
Happy intestine, happy brain?
Ingest probiotics (to feed microbiota) through what you eat, for example: kefir, Greek yogourt, fermented food, kimchi, etc., these are good probiotic providers. If your microbiota is low, you can take pills of probiotics, there are different brands, just be sure they have plenty of strains and a lot of millions of each of them. Remember you should have a diet full of good prebiotics and fiber (what probiotics eat). Just eat properly, consume a wide variety of vegetables, fruits, whole grains, legumes, and nuts; drink plenty of water, reduce stress factors, sleep well and avoid processed food and alcohol.
A final word…
Feeling blue is normal after some events, what you have to pay attention to is that it does not persist over time or affects your daily life. If it does, check your serotonin levels, what you eat and your habits. Remember that serotonin produced in the gut supports your brain serotonin, so a happy intestine means a happy brain and vice versa. More probiotics and prebiotics, less stress, avoid processed food and alcohol and enjoy the ride of life!
We hope this information is useful for you. If you need advice or have any questions about our treatments, please contact us. You can find us in Mill Hill Broadway and Islington. We are always happy to help. If you like this blog, please share!
References:
1.https://www.ncbi.nlm.nih.gov/books/NBK545168/
2.https://www.apa.org/monitor/2012/09/gut-feeling
