March 29, 2022
Tania Burgess

Feeding the Gut-Brain Connection: The Best (and Worst) Foods for a Healthy Gut

You will have heard the saying ‘listen to your gut’ thrown around in any number of situations involving a difficult or uncertain decision. On one hand it is a metaphor best translated to ‘listen to your instincts’, instincts we tend to think of as being derived from cognitive processes occurring in the brain. But the expression also happens to be a very apt reflection of an increasingly examined health focus: how the brain does indeed listen to the gut.

The idea of our diet impacting our body is not in itself a new conversation. Food habits affect parts of our lives as varied as our energy levels to our self-perception. Many of us will recognise the feeling of sluggishness after a big meal, or the rapid ‘buzz’ and ‘crash’ that follows a moment of sugary over-indulgence. What ongoing research is discovering are the myriad ways in which our entire digestive environment is itself shaped by what we eat, and how this could be having significant impacts on its feedback to our brain.

What is the gut-brain connection?

It would be fair to suppose the gut is one of the less complex of our bodily systems, responsible for breaking down food and excreting waste. But despite its relatively simple purpose, research is expanding around the critical relationship that exists between the gut and the brain, including important links between gut health and mood, mental health and risk of diseases such as cancer.

This connection is thought to be in large part thanks to the enteric nervous system (ENS), a network of nerves made up of its own cells and chemicals that extends all the way through our digestive system. On account of its structural similarities to the central nervous system that connects the brain and the spinal cord, the enteric nervous system is sometimes known as “the second brain”. Like the spine via the central nervous system, the gut is in a constant feedback-chain with the brain through the ENS, which helps make sense of why what we eat(and the way in which our gut is able to process what we eat) can heavily affect how we feel.

Knowing this, how can we better treat our gut to support brain-functioning and perhaps our overall mentality? Here are a few things to think about.

What are signs of an unhealthy gut? 

There is an array of signs and symptoms that have been identified as being indicative of an unhealthy gut, linked to both physical and mental wellness. These vary from person-to-person, but some common ones to look out for are:

  • Chronic stomach pains
  • Frequent gas and bloating
  • Diarrhea
  • Constipation
  • Skin breakouts
  • Mood swings and irritability
  • Brain fog
  • Frequent sinus congestion
  • Allergies and food sensitivities

Foods to reduce for a healthier gut 

The foods we eat contribute to the balance of ‘good’ and ‘bad’ bacteria in our digestive system. Whereas fibrous and fermented foods are rich in prebiotics and probiotics that promote ‘good bacteria’ for digestion, foods with heavy sugar and salt content can destroy good bacteria in the gut, unbalancing the body’s ‘microbiome’ and inhibiting digestion.

  • Salt-concentrated foods – Including foods high in sodium such cured meats, canned foods and salted nuts. An excess of sodium can lead to higher levels of water retention in the body, increasing puffiness and bloating.
  • Highly processed and refined foods – Examples are fast-food, packeted biscuits, pastries and chocolates. Without moderation, these foods can lead to loss of fibre, clogging to the gut. The refined sugars often concentrated in these food-types have also been linked to an inflammatory response in the gut.
  • Food allergens – Dairy, gluten, sugar, alcohol are common allergens that aggravate the lining of the gut, causing villi to break and damage. They can also destroy good bacteria and feed bad bacteria instead – this is what we are experiencing when we get bloated.
  • Sugary alcohols – Xylitol, Sorbitol and Menitrol are highly processed, artificial sweeteners made from alcohol can also disrupt the equilibrium of the gut.
  • Carbonated drinks – Fizzy drinks with bubbles add air to your water, and swallowing air is a main cause of bloating and gas.

Foods to increase for a healthier gut:

  • High-fibre foods – Foods including bananas, oats, wholegrains, peas, broccoli, leeks, sweet potatoes and dried fruits. Their high-fibre content allows for a smooth and regular digestive process, limiting the time waste spends in the body.
  • Fermented foods – This could be yoghurt, sauerkraut, kombucha, kimchi, miso and tempeh. These foods are rich in probiotics, the ‘good bacteria’ that helps to regulate a healthy microbiome.
  • Anti-inflammatory foods – Try some fatty fish such as salmon or sardines, berries, nuts and leafy greens. These help to reduce the inflammatory responses in the gut and the body more widely, reducing the likelihood of symptoms related to a sensitive gut.

Good habits for a healthier gut

While a healthy diet may have the most clear correlation to gut health, there are other habits we can integrate into our lives to naturally promote healthy digestion and positive brain-gut communication. These include:

  • Eating slowly and mindfully – Chewing slowly and avoiding eating while on the move can reduce the amount of air swallowed, decreasing the chances of gas and bloating. It also helps you to break down your food properly using your teeth, prior to entering your digestive tract. Smaller meals can also reduce bloating and digestive load, supporting the gut and the digestion process.
  • Regular exercise – Exercise gets the whole body – including the gut – moving. This supports metabolism and sets off peristalsis, the gradual propulsion of food along the digestive tract by surrounding muscles.
  • Consistent and sufficient sleep – The direct impact of sleep on gut health is still being explored, but studies have shown that those experiencing sleep abnormalities such as insomnia experience higher rates of GI issues than those who don’t. As sleep is what allows the brain to refresh and recharge, it’s also likely to have an impact on gut-brain communication.

While a more in-depth understanding of the gut-brain connection is still needed, their connection via the enteric nervous system means that a healthier gut could have truly positive implications for the way we think and feel on an integrated level.

Certainly by recognising the intricate and varied connections between different parts of the body, we might begin to adopt a more holistic approach to our physical and mental health. This includes paying attention to how our ‘first’ and ‘second’ brains are interlinked and how the managing the communication between them could provide a boost to our wellbeing.

So what is your gut telling you?