How to eat yourself calm: nearly all of your serotonin is made in the gut


If you think your brain is at the centre of all your stress, think again – our guts hold more anxiety-busting power than many of us realise.

It might sound a little Goop to talk of eating yourself happy, but it turns out that the idea of improving moodreducing stress and improving wellbeing via our stomachs is actually based in sound science. That’s because up to 95% of our serotonin (the happy hormone) is made in the gut.

Most of us know that our guts are packed with millions of bacteria and that these produce different neurochemicals our brains use to learn, remember and regulate mood. That’s what the gut-brain axis is all about. But what many of us may be less familiar with is the fact that our gut actually produces the chemicals that make us feel good.

Think about it for a moment: can you remember a breakfast, for example, that left you feeling really satisfied and happy? It might have been a big bowl of oats with nut butter, fruits and yoghurt. Or it could have been a few slices of chunky sourdough with marmite. Less fibrous breakfasts may be delicious but a croissant rarely leaves you feeling super-content.

It’s the same when you’ve spent a few days eating mainly beige foods. After a while, you start to feel grey inside. You might be constipated and bloated – and those physical feelings can often come with feeling irritable, listless and distracted. While those could be side effects of being overly gassy, it’s also likely that they’re caused by disrupted serotonin production.

Mental health advocate Dr Taylor Marae is a registered dietitian who shares content about health anxiety on Instagram, and she’s been celebrating the explosion of research into the role of the gut on mental health. “As a registered dietitian who’s been focused on functional nutrition and holistic healing since the beginning of my career, I scream this from the rooftops,” she writes of gut-based serotonin production. “We can heal so much inside of us, and yes, our mind too – the gut-brain connection is so real.”

A range of studies have come out in recent years stressing the important role of the gut’s microbiome on mental health. One study, published in Gastroenterology, fed typically shy mice a cocktail of antibiotics that dramatically changed the composition of their gut bacteria. That, the lead author said, ‘completely changed’ their behaviour, with the mice becoming bold and adventurous. When the antibiotic regime was stopped, the animals quickly reverted to their usual, cautious selves.

Research has also found that good bacteria can cause anxiety-prone mice to calm down, with a 2011 study finding that animals fed a broth laced with probiotics ended up becoming more adventurous and less panicked in the face of potential danger.


Obviously, humans are different to mice and there are any number of reasons why we might feel down, tired or stressed. We can’t eat our way out of depression or other chronic conditions. But it is good to know that we have the power to strengthen our happy hormone production to give ourselves the best chance of staying energised and resilient.

Given that serotonin production is reduced when you’re constipated, it’s also good to know how your gut impacts your mood if you live with irritable bowel syndrome (IBS). If you’re having to cope with mood and energy fluctuations on top of bloating, gas and cramp, IBS can start to have a really detrimental impact on your quality of life. But in recent years, scientists have found that targeting serotonin receptors in the gut can help to treat the disease.

As yet, no available medications specifically target serotonin changes seen in IBS, but you can alter your serotonin levels enough to affect symptoms yourself. Things like meditation and gentle exercise are known to increase production of the chemical, while research has found that eating foods high in tryptophan could help raise levels too.


“To support serotonin production, we want to ensure that we are looking after our microbiome – the collection of microorganisms that reside in the gut and manufacture serotonin and other neurotransmitters,” explains registered nutritionist Clarissa Lenherr.

She says that there are five main way  of doing this:

Diversify your diet: try to include a range of colourful fruits and vegetables at most meals, as a more diverse microbiome is generally a healthier microbiome.

Include fermented foods: fermentation cultivates live gut-friendly bacteria that may benefit the digestive system. Try incorporating kimchi, kombucha or another fizzing food three times a week.

Include prebiotic foods: insoluble fibres help to feed the existing microorganisms that reside in the gut.

Get in enough protein: tryptophan is an essential amino acid that is a precursor to the production of serotonin. Tryptophan is found in many protein-rich foods.

Eat oily fish: it contains omega-3 essential fatty acids, which may help serotonin function.


Eggs – the protein in eggs (including the yolk) has been shown to significantly boost your blood plasma levels of tryptophan.

Tofu – soy is calcium-rich and full of tryptophan

Pineapples – they’re packed with serotonin as well as enzymes that can help breakdown protein in the gut

Nuts – high in tryptophan, nuts and seeds are also packed with fibre, vitamins and antioxidants

Rice/wholegrain bread/oats – carbs are essential for maintaining a healthy, happy gut. Make sure you’re really filling up on roughage to fuel your gut bacteria.