Gut Health and the Brain

Dr Megan Rossi, The Gut Health Doctor

Boosting the health of your gut is one of the most effective ways to enhance your overall health and wellbeing – and that includes the health of your brain.


The gut and the brain are in constant two-way communication, a phenomenon that is known as the gut-brain axis - and when signals between the two are out of whack, it can trigger gut and other health issues.

While it’s relatively early days in the research, the ‘gut feeling’ phenomenon is something we’ve all experienced. Long before science connected the two, we were using the gut to describe our feelings and emotions, such as “getting butterflies” when we’re nervous and saying we “can’t stomach” certain activities or behaviour.

It’s due to this gut-brain communication that feeling stressed plays a big role in our gut health and can affect our gut bacteria. Trials have shown not only that our gut microbiota (that’s the trillions of microbes, including bacteria - living within us) is implicated in our mental health, but that by modifying our gut microbiota (GM) with simple diet and lifestyle strategies, we can help manage mental health issues, including depression and anxiety. A few small changes can make a big difference to enhance brain performance.

The biggest myth when it comes to looking after your gut is that you need to have a restrictive diet.

Quite frankly, juice diets and ‘detox’ cleanses are nonsense when it comes to gut health, and they can actually do more harm than good. You also do not need to give up all sugar, coffee and gluten, nor do you need to go 100% plant-based (although of course many do for cultural and environmental reasons).

In fact, eating a diverse diet is key, as good gut health is all about inclusivity and moderation. Aim for at least 30 different plant-based foods a week (including fruits, vegetables, whole grains, legumes, nuts and seeds). I promise it’s easier to hit your 30 than you think!

One of my favourite studies, the SMILES trial, has remarkably shown that a Mediterranean diet, super high in fibre (50g a day, most people in the UK are getting under 20g) from a range of plant-based foods and extra virgin olive oil, is effective in improving depression levels.

It has been proposed that the benefit to the brain may be due, at least in part, to an alteration in the gut-brain axis. How? Dietary fibre is essentially our gut microbes’ favourite food. When the microbes eat fibre, they produce a range of beneficial chemicals, some of which are thought to pass the blood:brain barrier, impacting our mood. Happy microbes = happy you.

When it comes to probiotics, a landmark study showed that a specific probiotic resulted in a reduction in depression scores, along with a significant change in brain activity (measured using brain scans). This is an incredibly exciting area and, while it’s important not to overhype the evidence so far, there is hope for probiotics in improving brain health – a new area called psychobiotics – so watch this space.

Simple ways to support your gut health to help your brain health

1.  De-stress with mindfulness. There’s growing evidence demonstrating the importance of mindfulness for the health of our brain. Studies suggest 12 weeks of daily mindfulness can help to de-stress and regulate gut issues.

2.  Load up on 30 different plant-based foods every week. Try sprinkling mixed seeds onto your meals, that’s 4 points. Instead of getting just red pepper, go for the green, yellow and orange too for another 3 points.

3.  Fall in love with extra virgin olive oil. In the SMILES trial that showed significant improvements in mental health after just 12 weeks on a Mediterranean diet, participants consumed 60ml of extra virgin olive oil every day.

4.  Get friendly with legumes. Beans and pulses are an underrated superfood if you ask me. They’re loaded with prebiotics (that’s food for your GM) and fibre, and they’re one of the most cost-efficient, nutrient-dense foods.

5.  Add a side of veg. If you’re always eating out, make sure there’s some plant-based fibre on your plate for your gut microbes, such as wholegrains, vegetables or legumes. If you eat meat, opt for smaller portions and always side it with fibre-rich foods to reduce the negative impact on your GM.

6.  Dabble in fermented foods. Traditional fermented foods, such as kefir (fermented milk) or kombucha (fermented tea), contain live microbes and beneficial compounds. Some also have brain-messenger molecules, which are known to have a calming effect on the brain.

7.  Sleep! Sleep disturbance, from restless nights or jet lag, can disrupt our GM and have a big influence on our brain health. Getting your 7-9 hours of sleep every night is so important, especially for best performance ahead of an important meeting or presentation.

When you’re going through a busy period and homemade meals drop way down your priority list, let me challenge this.

It’s exactly these times when you need peak performance and can’t afford to get ill, right? Frozen vegetables are an easy staple to have on hand. Cooking in bulk and having a rota with your partner or colleagues can also really help keep you on top of your game.
If you incorporate one thing into your daily routine, just 15 minutes of mindfulness with a meditation app (I use Headspace) every day can have a significant impact in reducing stress and rewiring the gut-brain axis.
Healthy gut, happy mind.

Who is Megan Rossi?

Dr Megan Rossi (The Gut Health Doctor) is considered one of the most influential gut health specialists internationally. A practicing Dietitian and Nutritionist for the last decade with an award-winning PhD in gut health, Megan is passionate about empowering others to take control of their health and happiness from the inside out. A leading Research Fellow at King’s College London and founder of The Gut Health Clinic, Megan is currently investigating nutrition-based therapies in gut health and has recently written her first book Eat Yourself Healthy, with the perfect mix of science, anecdotes and practical tips for optimal gut health and beyond.