Did you know that scientists now suspect we actually have two brains? Not in the sense you might suspect, but research is uncovering the strong links between the brain in our heads and our gut.

What happens when we don’t have a healthy gut?

“A healthy gut is ‘diverse’ and includes many different species of microorganisms. Reduced diversity can indicate imbalance in the gut. Imbalance of the gut microbiota can cause our normal gut function and psychological function to become imbalanced.

The gut and brain are dependent on one another to maintain balance or homeostasis. Because of this, our gut is associated with some neurodegenerative and behavioural disorders, and mental health conditions such as anxiety and depression.”   

Is it true that some mental health issues are associated with an unhealthy gut?

“Gut imbalance is associated with several mental health conditions, including depression and anxiety. There are trillions of bacteria in our gut and when the composition of this changes, some types of not-so-good bacteria can become dominant, and other good bacteria can become underactive. This can disrupt the gut environment, and contribute to the development of depression and anxiety symptoms. Inflammation, in particular chronic inflammation of the gut such as with Irritable Bowel Syndrome (IBS), has also been linked to depression and anxiety.”

Can people tell if their depression or anxiety is associated with gut issues?

“Someone with depression or anxiety could investigate their gut microbiome profile to see if the community of bacteria are in balance, or if there are some bacteria that are dominant. An overgrowth or dominance of some specific bacteria are associated with different moods, and symptoms related to depression and anxiety. 

Some bacteria for example, are able to produce serotonin, which is the neurotransmitter that regulates feelings of depression, happiness and satisfaction, and it also regulates our sleep-wake cycle. In fact, it’s estimated that 90% of serotonin is produced in the gut! It’s no wonder that gut dysbiosis [imbalance] is linked to our mood and behaviour. Other gut bacteria can activate GABA, the neurotransmitter that controls feelings of anxiety of fear.” 

Can changing what we eat potentially improve our mental health?

 “Absolutely! One benefit of knowing about the influence of our gut on our mental health, and health overall is also knowing how we can nurture and nourish this environment with simple nutrition.

Eat a rainbow

A diet rich in vegetables and fruit will be high in dietary fibre, which is important for the gut and microbiota. Ideally, our diet should be high in variety. It should also be colourful! Food comes in every different colour, especially veggies and fruit. To prioritise variety and balance, we can ‘eat a rainbow’ at meal time.

Eat probiotics

I would also suggest introducing probiotic and prebiotic foods into your diet. Probiotic foods contain living bacteria that are beneficial to our gut (e.g. lactobacillus and Bifidobacterium). Try Greek yoghurt, kefir, kombucha, sauerkraut, and kimchi.

Eat prebiotics

Prebiotics are a form of dietary fibre that feed the healthy bacteria in our gut, allowing them to grow. Prebiotic rich foods include Jerusalem artichoke, leek, asparagus, onion, garlic, apples, and underripe bananas. Including both prebiotic and probiotic foods supports a healthy community of gut microbiota.” 

Anything else you recommend to people seeking to improve their gut health?

“Lifestyle factors can influence our gut health too. Stress, alcohol and tobacco, environmental chemicals and pesticides, food additives and some medications can change the balance of gut microbiota and therefore influence our health outcomes – so be mindful of these where possible.”