How our belly influences our brain?

12 Sep 2018

Heard of the ‘second brain’? Apparently, it’s our tummies and evidence suggests our gut’s health greatly influences our mood. Here’s what science has to say about it.

Ever been told to ‘trust your gut’ when you ‘get a gut feeling’? And what about the feeling of having ‘butterflies’ in your stomach? Clearly there are no winged insects fluttering freely inside us, but the sensation of feeling slightly uneasy and funny in the tummy when we’re anxious, nervous or scared is legitimate.

In reality, the ‘fluttery’ feeling is a neurological response to stress, sent from our gut directly to our brain via the enteric nervous system, otherwise known as the gut-brain axis. In the enteric nervous system is a mesh-like system of around 100 million neurons – more that in the spinal cord – lining the entire digestive tract. When they’re stimulated (often by psychological stress) these cells are the first to shoot the message up to the brain. In short, your stomach is extremely influential over our overall mood.

This system of neurons communicates constantly with the trillions of bacteria living inside our gastro intestinal system. This community of stomach bacteria, plus yeasts, fungi and viruses is called our gut microbiomeand has evolved with us since birth. It does myriad things – digest our food, train our immune systems, help fight viruses, banish toxins from our bodies, and so on.

When our gut microbiome is unhealthy, negative messages are passed through the enteric nervous system back to the brain. Keep this ecosystem healthy, and there’s evidenceto say we can curb inflammation, depression, lower our reaction to stress, improve memory, reduce anxiety and more.

So how do we feed our second brain to ensure it’s at optimum health and inflammation is kept at bay?

  • Make sure there’s enough soluble fibre in your diet. Foods like whole grains, legumes, fruit and vegetables keep things moving through your digestive tract preventing you from becoming bloated and constipated.
  • Eat a diet that’s low in refined sugar and saturated fat. Both are known to influence gut bacteria negatively, allowing harmful species to thrive. If you regularly feed the bad bacteria, you allow them to colonise and grow more quickly meaning you no longer have a healthy balance in your gut. PLUS, people with a higher concentration of bad bacteria tend to absorb more calories than those with a healthy balance.
  • Don’t take antibiotics if not necessary – antibiotics can cause permanent changes in certain types of healthy bacteria.
  • Eat prebiotics, which are healthy bacteria mostly found in carbohydrates and fibre such as legumes, beans, peas, oats, bananas, and berries. Prebiotics are turned into a short-chain fatty acid called butyrate, which has been proven to have anti-inflammatory effects on the digestive system. They may also block the growth of cancer cells and help healthy cells grow and divide normally.
  • Eat probiotics, which are foods such as natural yoghurt (look for supermarket brands that promote strains such as Lactobacillus acidophilus and Bifidobacterium lactis) that are cultured with strains of healthy bacteria. Other foods known to be probiotics include fermented foods like sauerkraut, kimchi and kombucha; kefir and non-pasteurized pickles (the process of pasteurising kills bacteria).


Want to know more about how fermented foods can improve your gut health? Read our interview with kimchi and kraut producer, Green Street Kitchen, here, and our article on the benefits of drinking Kombucha here.