Is Your Gut Really Your ‘Second Brain’?

Trillions of microorganisms call your digestive system home. They could be the key to a healthier, happier life.

Words: Ed Coope

You’ve searched the term on Google, watched videos about it on TikTok and scratched your head over it countless times, but what actually is gut health? And could your gut, loaded with neurotransmitters and neurons, be acting – as a growing body of research is hinting – as your body’s ‘second brain’?

First, let’s have a quick refresher on the role your gut plays and what’s meant by ‘gut health’. “The gut hosts 70 percent of your immune system,” explains nutritional therapist Jenny Tomei. "Your gut microbiota [the community of microbes that call your gut home] weighs about two kilograms and is bigger than the average human brain. It contains a community of trillions of bacteria, archaea, fungi and viruses, containing at least 150 times more genetic material than the human genome."

Hardly surprising, then, that this ecosystem of bacteria, neurons and neurotransmitters – collectively known as your 'microbiome' – is directly linked to both your physical and mental health. “When our gut microbes are out of balance this can have a big impact on our brain health and function, including depression, anxiety and brain disorders,” says Tomei, expanding on how external factors can influence internal bodily functions and vice-versa. “Our diet and lifestyle are essential for a healthy gut microbiome, and we can impact this by changing what we eat, how we eat and by reducing stress.”

It’s relatively new science, too, as there are continually new studies being published that correlate the health of the gut with our overall wellbeing. “Scientists are only just discovering the huge impact of our gut health and how it could play a key role in everything from tackling obesity to overcoming anxiety and boosting immunity,” Tomei says. “Constant studies are coming out that suggest a diverse population of gut microbes is associated with better health.” With that in mind, here are three ways you can make your gut health work for you.

Diet

“Add fermented food like kefir or sauerkraut to your diet. Fermented foods contain live beneficial bacteria, which has shown to have benefits on our overall gut health including digestion,” advises Tomei. “Think about what you can add into your diet, instead of looking at what you’re going to cut out. Variety in the diet is key, which will lead to a healthier gut microbiome.”

Sleep

Even as you recharge, your gut is working hard to keep your feel-good hormone serotonin in check, and to keep your sleep/wake cycle optimal. “Poor quality sleep can impact our gut microbes, and this can cause an increase in inflammation and our stress hormone, cortisol,” says Tomei. “This may also explain why lack of sleep is linked with an increase in gut symptoms. A lack of diversity in our gut microbiome can also impact our sleep patterns, as some mouse studies have shown gut microbe depletion is linked with a lack of serotonin in the gut, which can affect sleep/wake cycles.”