Serotonin – it’s all in the gut. Here’s How to Boost Yours!

Known as the ‘feel good hormone’, serotonin is recognized for giving us those mood-boosting feelings.

This happens when we eat a satisfying meal, see a movie that makes us smile, or maybe watch the sunset with a few close friends. It leaves us feeling a deep sense of calm and happiness. 

But serotonin doesn’t just impact our mood. This powerful hormone lends a hand to many biological functions – think appetite, digestion, getting a good nights sleep, memory, motor skills, blood clotting, sexual function, and much more.

In fact, it’s estimated that nearly 95% of serotonin is produced in the gut and one of the main reasons why researchers emphasize the importance of ‘the gut-brain connection.’

Low levels of serotonin have been linked to an increased risk of irritable bowel syndrome, depression, as well as feelings of fear and anxiety (3). It’s no doubt that low levels of serotonin directly impact the health of our microbiome, and thus, the well being of our mind.

In this blog post, we’ll be taking a deeper dive into serotonin, unpacking what exactly goes on in the gut, and providing plenty of resources to ensure your levels are where they need to be to leave you feeling calm and at-ease

Let’s get this straight: Is serotonin a hormone or neurotransmitter? 

As it turns out, serotonin takes on dual roles as a hormone and a neurotransmitter. When found in the brain / spinal cord (central nervous system), it acts as a neurotransmitter. If it’s found elsewhere in the body, it functions as a hormone. 

Often confused with dopamine, the other ‘feel good hormone’, serotonin relates closer to focus, happiness, and feeling calm while dopamine is tied to motivation and reward. However, they both play beneficial roles in boosting mood and reducing anxiety (3).

Other functions of serotonin include (1):

We need adequate serotonin levels to THRIVE!

– Reducing inflammation

– Bowel motility

– Regulating body temp

– Wound healing

– Bone health

Serotonin and the gut:

As we mentioned, close to 95% of serotonin is found in the gut!

It’s one of the reasons why researchers often refer to the gut as ‘the second brain’, or in more scientific terms, the enteric nervous system (ENS). It communicates with the first brain and when our bowel function is off (feeling bloated, constipated, or experiencing diarrhea) it talks to the big guy upstairs – triggering major emotional shifts.

Research has shown that serotonin triggers gut motility as it binds to specific receptors within the gut (3). This is incredibly important as it encourages proper digestion and prevents constipation.

If we’re not properly excreting, toxins form and accumulate within the digestive tract, creating inflammation that can negatively affect our entire body. In the same token, as serotonin stimulates elimination, it aids in regulating our appetite, blood sugar, and metabolism.

While there is still a lot about serotonin that we’ve yet to discover, director of the Johns Hopkins Center for Neurogastroenterology, Jay Pasricha, M.D., explains that researchers have been long aware of the connection between our first brain and the gut; however, it was originally thought that feelings of anxiety and depression created digestive discomfort.

Nowadays, scientists are finding that it’s actually the inflammation within the gut communicating with the central nervous system that causes major shifts in our mood (4).

This means that the irritated microbes within our gut start speaking to our brain which can lead to increased feelings of anxiety or depression. 

Pasricha goes on to state that these changes may explain why many people with IBS experience higher-than-normal percentages of anxiety and depression (4).

Given its close connection to the digestive system, it’s easy to understand just how important it is to nourish the gut as a way to support our mental health. 

Why might serotonin levels be low?

As we just mentioned, it begins in the gut. 

The food we eat fuels the microbes in our digestive tract which are dependent on specific nutrients to produce serotonin (among many other processes within the brain). Those tiny bugs are quite talkative and if they’re not properly nourished, they have no problem telling the brain, ‘hey, something is off so we’re changing it up.” 

Serotonin may also be depleted if we’re not receiving enough Tryptophan in the diet – an amino acid needed to build serotonin. It’s important to note that carbohydrates are essential for transporting tryptophan across the blood brain barrier. This is something to keep in mind if complex carbs are lower in your diet.

Another nutrient critical for its production is vitamin D, a common deficiency in our modern world (6).

Finally, high amounts of alcohol consumption, hormonal birth control, and as well as increased cortisol (stress) levels may further contribute to serotonin depletion.

Tools to begin increasing serotonin levels:

As with all of the hormones we’ve discussed so far, there are many ways to boost serotonin! In fact, I have an entire blog post where I share 5 Diet Tips to Help Boost Serotonin Production.

While food is one of the best ways to naturally support serotonin, below are some other lifestyle factors that can further help.

RELAX IN THE SUN: As we noted above, vitamin D is needed to activate the necessary enzymes for serotonin production. Inadequate amounts may cause serotonin levels to dip, something we often see in seasonal affective disorder (SAD). Aim for daily sunlight exposure to combat this, take it one step further by letting yourself be barefoot in the grass to soak up the earth’s grounding sensations.

PRACTICE REGULAR MOVEMENT: Researchers have shown that regular exercise has supportive effects on mood-boosting neurotransmitters like dopamine and serotonin (3). It also increases tryptophan levels in the brain – the precursor for serotonin! However this looks for you, set aside time to move your body. It could be an hour-long workout or short increments of movement throughout the day. 

GET A MASSAGE: Personally, just the thought of getting a massage boosts my mood! And as it turns out, evidence exists to support this. One study showed that women who received regular massages from their partner experienced less anxiety and overall happier moods thanks to an increase in serotonin and reduction in cortisol (6). So… coax a loved one into giving you a massage, and remind them they’ll also benefit from a happier you 😉 or go ahead and treat yourself by booking one with a massage therapist!

DO THINGS THAT LIGHT YOU UP: What’s one thing that immediately brings a smile to your face? For me, it’s a random dance party, chatting with my bestie, a dip in the ocean, or the first sip of my morning cacao. These things bring an overwhelming sense of release that reduce stress and save our serotonin. I encourage you to write a list of things that create that feeling for you and keep it somewhere accessible. Then when you’re feeling low, you’ll have immediate tools in your ‘mood boosting tool box’ that won’t require much thought.

Final Words:

As you can see, serotonin plays an incredibly important role within our bodies – from boosting mood, easing anxiety, to supporting digestion, regulating body temperature, impacting appetite, reducing inflammation, and so much more! 

Now you better understand this important chemical (that duals as neurotransmitter & hormone) and know that there’s SO much you can do to boost your levels.

As always, food plays a key role in keeping serotonin levels in check – as does lifestyle factors. If you haven’t yet be sure to check out this blog post on foods to help boost serotonin.

And remember there are many lifestyle factors that can impact serotonin levels such as:

  • The food you eat!
  • Spending time in the sunshine to soak up Vitamin D
  • Practicing regular movement
  • Getting massages
  • Doing things YOU love

As I often say, we get to make feeling amazing and inside job – and looking at ways to boost our serotonin is a great way to start!

If you want to know more about how you can use your diet as a tool to boost your mood help you feel more calm, grounded, and at ease – check out my “Eat to Ease Anxiety” Online Course! 



And lastly, a big thanks to McKenna Garrison for all her incredible work on this blog post. 

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