Can gut health impact mental health?

We hear more and more about the gut-brain axis—but what is the gut-brain axis, how does it work, and can probiotics improve your mental health?

What is the gut-brain axis?

Have you ever felt butterflies in your stomach before an interview? That’s the gut-brain axis in a nutshell—the symbiotic relationship that exists between your brain and your microbiome. In fact, the brain and gut are in constant communication, regulating mood, maintaining your calm, and promoting better sleep.

The gut and the brain are connected in more ways than one. Physically, they’re connected by the vagus nerve, which links the brain and the enteric nervous system (the network of neurons in your gut. And chemically, the gut microbiome produces around 95% of your serotonin , and 50% of your dopamine —neurotransmitters with essential roles in balancing and regulating your mood.

There’s over 400 trillion bacteria cells living in your gut right now… just let that sink in. That means that right now, there’s trillions of living organisms dictating the health of your microbiome, and by extension, your brain. So for the sake of your mental health, it’s important to keep your gut happy and healthy.

The HPA system

This is where it starts to get complicated. Microorganisms in the gut can create or break feedback loops in the hypothalamic-pituitary-adrenal system . This is a complex system of pathways that link these three glands through hormones and brain signals. The impact of the gut microorganisms on this axis can help up-regulate and down-regulate the production of cortisol.

And at the same time, information from the brain influences the gut and its bacterial populations, to ensure that the correct signals are travelling through the HPA system. It’s a two-way street.

Can probiotics support the gut-brain axis?

Certain strains of bacteria and yeast are able to impact on the gut-brain axis—these are often referred to as psychobiotics, and research has shown that a strong, well-regulated gut-brain axis can have a serious impact on your mental health.

Probiotics are full of good bacteria and other microorganisms that help keep your digestive system healthy. They do this by crowding out bad bacteria and yeast, which left to their own devices, can disrupt the gut-brain axis, which could lead to feeling emotionally unbalanced or worried.