You have probably heard the terms ‘gut feeling’ and having ‘butterflies in your stomach’ but did you know that your gut and brain really are closely connected? In fact, there is a name for the communication network that connects your gut and your brain: the gut-brain axis.
Your brain and digestive system communicate in a few different ways:
Your gut connects to your brain through nerves, the biggest being the vagus nerve. The vagus nerve carries signals between the digestive system and the brain. It helps to manage many complex processes in your digestive system including the contraction of smooth muscles to move food through your gut, and the control of gastric secretions, such as stomach acids which help to break down food.
Cells in the lining of your gut produce neurotransmitters, chemicals which relay information to and from the gut and brain, and play a role in our feelings and emotions.
The bacteria in our gut (called the gut microbiome) can also produce neurotransmitters, along with other important metabolites including short-chain fatty acids.
This two-way communication between the gut and the brain explains why feeling stressed or anxious can lead to stomach upsets, and digestive problems can affect our mental health.
While research is ongoing, studies have shown that building a healthy gut microbiome may be one way to promote mental health and wellbeing, and treat mental health conditions. We don’t yet have all the answers but evidence suggests that specific dietary changes can help to build a healthy gut microbiome. These include:
Eating more fibre-rich plant foods including vegetables, fruit, wholegrains, legumes, nuts and seeds.
Aiming for diversity in your diet – this means choosing a wide variety of different plant foods each day and from day-to-day. Aim to make your plate as colourful as possible and try a new fruit or vegetable each time you shop.
Eating foods rich in prebiotics including onions, garlic, Jerusalem artichoke and legumes.
Avoiding ultra-processed foods.
There is also emerging evidence that certain strains of probiotics may be helpful in the treatment of mental health conditions such as anxiety and depression. The term psychobiotics has been used to describe probiotics and prebiotics that might provide benefits for mental health. However, more research is needed to determine the specific strains, dose and duration of treatment needed for different mental health conditions.
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