When it comes to your gut-brain axis, one of the worst things you can do is let your stress levels get out of control. Stress can wreak havoc on both your brain and gut health, because the vagus nerve – which connects the two – is also part of the nervous system, which modulates the body’s stress response.

It’s for this reason why you might get butterflies in your stomach when you’re nervous, or why research has shown that gastrointestinal irritation could trigger stress and anxiety. It’s a cycle – and that’s why taking care of your stress levels is important for the entire gut-brain system.

“Chronic stress is a really big issue,” Dr Leeming says. “The pace of the modern world means many of us subconsciously live in a fight-or-flight state, and we know that that heightened state of stress can have a detrimental effect on our gut bacteria, which can then affect our brain.”

“I’m a microbiome scientist – these are the 6 bad gut habits to avoid if you want better brain health”