The link between our gut bugs and our mood

We’re all familiar with the phrases 'gut feeling', or 'going with your gut', and many of us know well the feeling of losing all appetite when we’re feeling sad, or getting an upset stomach when we’re anxious about an upcoming event. Now, scientific research is starting to provide answers about the link between our gut and our feelings and moods. We’re starting to understand more the conversation that happens between our brain and gut via a specific part of the nervous system called the enteric nervous system. We also know that a good deal of our 'happy neurotransmitter' - serotonin - is made in the gut.

Introducing our gut bugs

One of the newest areas of research relates to the millions of microbes we all have living in our gut. The terms 'gut microbiota' and 'gut flora' refer to the microbes that live in the digestive tracts, and we’re increasingly starting to see that the composition and health of our gut flora can directly impact mood. Why is this important?

Well, there is a lot we can do with diet and lifestyle to support healthy gut microbiota, and therefore our mood.

First, let’s understand a bit more about how the microbes in our gut can affect mood. There is mounting scientific research that points to a two-way conversation between microbiota/gut/brain. The microbes in our gut effectively 'talk' to the rest of our body via a number of different pathways, including our immune system, nervous system, and hormonal systems. Certain types of gut bacteria also help produce neurotransmitters, such as serotonin. When everything is working as is should, the human gastrointestinal tract should be home to a very diverse range of microbes. Billions in number, and composed of many different families of bacteria, fungi, and viruses.

Things can start to go wrong when the diversity of microbes is too low, or when we see an overgrowth of a problematic type of microbe. This is referred to as 'dysbiosis', which can cause a release of signals that tell the rest of your body that there is a problem, contributing to low mood, among other symptoms. Studies have observed that low diversity in the gut, and the resulting dysbiosis, can be an underlying factor in some mental health conditions.

What affects our gut flora?

Sadly, modern living isn’t particularly good for a healthy range and number of gut microbes. Our gut microbiota thrive on fibre, and unfortunately the modern western diet that many eat is fairly low in fibre. Most of us also don’t eat a very varied diet; we tend to eat roughly the same thing, day in and day out. This lack of variety leads to a lack of diversity in the gut, as a wide array of different nutrients and different sorts of fibre are needed by the gut flora.

Antibiotics can be lifesaving, but as well as killing dangerous bacteria that are causing illness, they decimate the bacteria in the gut. Sometimes taking antibiotics is unavoidable, which is why taking steps to nourish our gut bacteria after the course is finished is so important.

Supporting mood by feeding your gut bugs

There are some simple dietary changes that you can make to support your gut flora and overall gut health, with the aim of supporting mood. Let’s go through them;

• Eat a variety of fruits and vegetables. Aim for at least two pieces of fruit and five portions of vegetables each day, ideally. This will provide plenty of fibre for your gut microbes to feed on. Remember, variety on the plate translates to diversity of gut bugs, so aim to eat a rainbow - plenty of different colours - each day.
• Eat fermented foods such as yoghurt, kefir, sauerkraut, kimchi, and kombucha. These foods naturally contain good bacteria and yeasts, and can help support the diversity of your resident microbes.
• Limit intake of processed foods. Highly processed foods, such as ready-meals and fast foods, are associated with reduced microbiota diversity and increased inflammation.
• Reduce consumption of refined sugar and artificial sweeteners. Both have been associated growth of unhealthy bacteria in the gut, and overall lack of microbiota diversity.
• Try an overnight fast. Aim to wait 12 hours between eating your dinner and breakfast (and avoid any late-night snacks!). This gives your gut time to stimulate microbe growth overnight.

Try introducing the five steps above and monitor any changes to your mood. How do you feel? While eating a nutritious diet is always going to benefit your overall health and well-being, it’s a good idea to seek help from a healthcare professional, such as your GP, if you feel you need additional support for your mental health.

Registered nutritional therapists are also trained to carefully assess what diet and lifestyle patterns may be contributing to mood problems, and will devise a personalised programme to support you on the road to better health.