Gut health guide: What to eat for better digestion, skin, mental health & more

How healthy is your gut? Are you constantly sick? Depressed? Can’t sleep? Got acne? Amazingly, as well as breaking down foods and absorbing nutrients, the gut has a huge impact on how efficiently the body and mind works.

A healthy gut, like the rest of your body, is  largely based on your diet and water intake, although sleep and exercise plays a part. It's so important to maintain a healthy gut, whether that's by taking in enough omega-3s (hello, our best fish oil supplements list) or drinking enough water (best keep one of our best water bottles handy). Studies have found a healthy gut can even prevent some cancers and autoimmune diseases.  So it’s clear that gut health is important, but how does it all work?

Put simply, the lesser-known enteric nervous system in our guts (known as our “second brain”) communicates with the brain in our heads. They work closely together to help keep the body healthy and fight disease – a complex relationship known as the gut-brain axis.

“The gut has an ecosystem of microbes, known as the gut microbiome, and they talk to the rest of the body,” explains gastroenterologist and integrative medicine doctor Dr Singh. “The gut and brain are also connected to each other through the ‘vagus nerve’, which serves as an Information Super Highway, where messages zip up and down all day long,” says Dr Singh, who is also founder of functional medicine clinic Precisione Clinic.

“We can optimise our gut-brain connection by eating a proper diet, good sleep hygiene, avoidance of toxins, stress reduction, regular exercise, and cultivating social interconnections. Believe it or not, the microbiome responds to these lifestyle interventions.” 

Read on to find out more about how the gut influences different parts of the body and what to eat for better gut health.

 Gut health and digestion 

One of the main roles of the gut is digestion – it has an immense network of small and large intestines (combined length of 15 ft.!) and these help to extract nutrients needed from food to help the body function.

And while we’re talking stats, about 100 trillion bacteria, both ‘good’ and ‘bad’, live inside your digestive system. “Some foods are digested slower than others and make it all the way down to the large intestine, where they feed the good bacteria, leaving us fuller for longer,” explains Tina Manahai, MD., from health food specialist Healthy Supplies.

The Gut-Skin Axis

If you’re always struggling with bad skin, your diet – and in turn poor gut health - could be to blame. As we know, what we eat and how our body digests food has a huge impact on our emotional and physical health, and that includes acne and other skin conditions like rosacea and eczema.

More than 80 per cent of the body’s immunity is located in the gut so it’s hardly surprising that what’s living in there is going to influence how healthy – or unhealthy - we are, and that goes for your skin, too. 

“Stress is disastrous for your skin as it causes the release of free radicals – unstable molecules that damage our cells, deplete its ability to form a protective barrier, and cause dryness, dullness and wrinkling,” says Manahai.

For clear skin you need a healthy stomach full of good bacteria and probiotics that work to strengthen the lining of the gut, boosts the immune system and reduces inflammatory conditions like acne. Probiotics also appear in our flat tummy diet plan, as they can help prevent bloating caused by fermenting harmful gut bacteria. 

Gut health and mental health

“If our gut is deficient in good bacteria, this negatively affects our behaviour and happiness levels,” says Manahai.

“When we eat a healthy, varied diet, our guts work to extract and use important nutrients that can improve our mood and reduce anxiety, such as tryptophan - found in nuts, oats and seeds - which stimulates the production of serotonin, known as ‘the happy hormone’.

A recent Australian study looked at whether changes in diet could help depression and they had some impressive results, says dietician Sasha Watkins from Field Doctor. Participants who had been medically diagnosed with depression adopted a Mediterranean diet for 12 weeks. By the end, 32 per cent were in “full remission” and were no longer considered depressed.

Gut health and sleep

Can’t sleep? New research from the University of Tsukuba in Japan suggests that gut bacteria may influence normal sleep patterns by helping create important chemical messengers in the brain, such as mood-boosting serotonin and dopamine.

What we eat, and how our gut deals with it, also affects our ability to relax and sleep well. Bad food can wreak havoc with our circadian rhythms (the body’s internal clock), but by contrast a balanced diet helps our gut to release the nutrients needed for restful, revitalising sleep and this releases the hormone melatonin, which makes us sleepy.

What to eat for better gut health

Varied diet

Eating a colourful mix of foods including vegetables and fruit is key to a healthy gut, says gastroenterologist and integrative medicine doctor Dr Singh.

“Avoid processed foods, eat organic if you can, and this will help deliver good fibres and plant nutrients to the gut microbes in the colon. These ‘microbiota-accessible’ carbohydrates as we call them serve as fertilizer for the good microbes.

“When we eat a variety of different kinds of plant foods then we are able to feed a variety of different microbes, by doing that we can help diversify our gut microbiome and the functions they can perform may be improved. 

“For example, eating plenty of fibre in your diet helps the microbes make an anti-inflammatory short chain fatty acid called butyrate; this metabolite or compound can potentially help reduce inflammation and help create an overall better environment in your gut...and thus, the rest of your body.”

Fibre

Gut bacteria needs to be fed and one of its favourite meals is fibre, says registered dietician Sasha Watkins. 

“The more the better,” she says. “It’s also important that we eat different types of fibre - soluble and insoluble. A study I read about recently showed that people who ate more than 30 different fibre-rich plant types a week had more diverse microbiome than those who didn’t.” 

While protein, carbs and fats are often absorbed into the body before they reach the gut, fibre reaches the intestine mostly unchanged, as humans lack the enzymes to be able to digest it.

“However, once there, it really benefits the gut bacteria, which feast heartily on it and reward us by helping to maintain a good level of health and happiness.”

Types of soluble fibre include:

• Sweet potatoes
• Broccoli
• Pears
• Kidney beans
• Figs
• Apples
• Linseeds
• Chia seeds

Types of insoluble fibre include:

• Wholegrain foods such as brown rice
• Root vegetables 
• Spinach
• Beans
• Pulses
• Lentils
• Nuts 
• Seeds

Reduce alcohol intake

A healthy gut achieves equilibrium (known as homeostasis) when the good bacteria and bad bacteria balance each other out. Chronic, excessive drinking however tilts the balance towards the more harmful bacteria.

Studies have shown that people who regularly drink alcohol, including to excess, have guts that look very different to those that don’t (and not in a good way!). Alcohol can also blunt the immune system’s ability to fight off infection leading to an increased risk of illness. 

So it’s fairly obvious that ditching the booze can help boost the body’s natural defenses by preventing the bad bacteria from ruling the gut.

Eat less refined sugar

Much like alcohol, a diet rich in processed food and refined sugars can decrease the number of good bacteria in the gut. 

High amounts of processed sugars have been linked to increased inflammation in the body, which can lead to disease and serious illness.

Eat more omega-3 rich foods

Food rich in omega-3 fatty acids have been shown to affect the gut microbiota by increasing the good bacteria as well as the production of short-chain fatty acids, which are compounds that help to reduce inflammation and help boost immunity. 

Omega-3 rich foods include mackerel, salmon, flax seeds, chia seeds, walnuts and soybeans.

Drink more water

The body needs water to expel toxins and for lubrication for the digestive system to work efficiently (it even helps soften stools for smoother bowel movements).

It’s been shown to help balance the good bacteria in the stomach, where it helps the gut break down the food we eat.