As a nutritionist, gut issues are my bread and butter. However something most people wouldn’t associate with gut issues are mental health disorders. Yet I see it over and over again and research has proven that patients with persistent gut issues are much more likely to present with anxiety, depression and sleep disorders.

So what’s the connection? Why does the gut seem to be linked to the brain? Our gut has three major functions – the breakdown and absorption of nutrients, the elimination of waste and housing of our microbiome. Although a core understanding of our body’s function has been established for decades, we are only now identifying and understanding the role of the microbiome.

The microbiome is a collection of 100 trillion microscopic life forms living within our gastrointestinal system. These microbes are so numerous they make up about 1.5-2kg of our body weight. With over a thousand different species of bacteria we’re still discovering new strains. Just like any jungle, the bacteria in our gut create a unique ecosystem, which relies on our dietary habits to thrive.

If the thought of almost 2kg of bacteria living within your gut wasn’t crazy enough, these bacteria have the ability to influence/control the way our body functions and our mind thinks. Leading scientists now identify that the microbiome is one of biggest modifiable factors to our health.

So how does the gut microbiome influence our mood and mental health? The gut has 100 million nerve cells, which communicate with the brain everything that’s going on within the gut. An unhappy gut results in an unhappy brain, just like an unhappy brain can result in an unhappy gut. I’m sure you’ve all experienced butterflies in your gut, diarrhea or constipation during times of stress or even vomiting before a huge event. These are all examples of the gut and brain communicating.

Our brain and nervous system relies on chemical messengers called neurotransmitters that pass information around the body. Some of the most common neurotransmitters are; Serotonin (feel good, happy), Dopamine (reward and cognition) and Melatonin (sleep).

So would it surprise you to hear that 95% of your serotonin is produced in your gut, there are 400x higher concentrations of melatonin in the gut than anywhere else in the body and several different bacteria in the gut actually produce dopamine? Therefore, an imbalance in our gut bacteria has the ability to directly influence our brain biochemistry and change our mood.

So what can we do? The food we eat directly feeds, and has the ability to change, our gut’s microbiome. Research has shown that the western diet and processed food increase the risk of depression. By eating foods that our good bacteria love we can drastically improve our gut and thereby our mood. The first step is eating real food. Make things from scratch, no additives or flavors, avoid added sugar and consume plenty of vegetables with small amounts of meat. Remember that seeking help from a health professional who is able to accurately assess your microbiome can provide you with support needed to be both healthier in body and mind. ■

Benedict is a clinical nutritionist who practices at www.learntonourish.com in Hobart.