Expert advice on how to boost your microbiome and ditch digestive issues – no psyllium husk required.

You’re probably aware that wolfing down 30 different fruit and veggies weekly and guzzling water from a 1.8-litre Stanley cup is a boon for bowel health. Most of us know what we should be doing to optimise our gut microbiome – the ecosystem of trillions of healthy bacteria and organisms that live in the gut – but some of us still regularly cop digestive issues. 

According to the Body+Soul 2025 Health of the Nation report, 58 per cent of Aussies experience unpleasant symptoms such as bloating, gas, constipation or diarrhoea once a month, or more. And this has flow-on effects, so to speak.

“The gut is essentially the centre of our health,” explains nutritional biochemist and bestselling author, Dr Libby Weaver. “When our gut isn’t working as well as it could be, everything suffers.” 

So if your gut is telling you it needs a tune-up, strap in because these surprising, evidence-based tips could be worth a try – along with the basics, of course. “You truly can improve your gut health by eating lots of different plants, increasing your fibre, moving more and drinking enough water,” says dietitian Lyndi Cohen, aka The Nude Nutritionist. “Get the essentials under your belt, then add the frills.” Let’s do it. 

Address your stress

Yep, gut health affects mood, but it’s a two-way street. Your mental health can also impact the gut. “There’s a connection between stress and negative mental health and gut motility – how quickly or slowly food passes through your system,” explains nutritional psychiatry expert, Dr Megan Lee. 

“When we’re feeling stressed, food might take longer to go through the digestive system, creating problems for the gut, such as constipation.” Why? Because under acute stress, the body enters ‘fight or flight’ mode, which redirects energy from digestion towards more vital or urgent activities. Thousands of years ago, this could have been running away from a sabre-toothed tiger. 

Consistent constipation can in turn lead to low-grade inflammation, haemorrhoids, pain and sluggishness. Of course, stress and anxiety can induce frequent diarrhoea in some people, too, which can prevent the gut from properly absorbing nutrients from food. So however you like to de-stress, try to do it a little more often.

Change for the bitter

Sharp or bitter vegetables, like broccoli, spinach and cabbage, stimulate bile production – which apparently is something we want. “When the receptors in the mouth taste something bitter, they send a message to the liver to produce more bile because the plant might 

be poisonous and need to be digested quickly,” explains Dr Weaver. “Of course, bitter veggies aren’t poisonous – they’re full of nutrition.” 

The upside is the enhanced bile flow emulsifies fats and unlocks nutrients, especially fat-soluble ones like vitamins A, D, E and K. Brazil nuts and beetroot are also helpful for bile production. Good to know.

Bake blue cupcakes

Yep, you read that right. It’s rudimentary, but you can test your ‘gut transit time’ by scoffing on a muffin made with a few drops of blue food colouring and white flour, suggests Cohen. The blue dye should be visible in your stool around 28 hours later, give or take.

“See how long it takes for the muffin to exit your body; this travel time can tell us something about the health of your gut,” she adds. “I did this with my family – it’s fun and it really works. If you’re going on 48 hours’ transit time, for example, you might consider speeding up your digestion by exercising or consuming more water or fibre.”

Mind the meal prep

Sure, batch cooking saves time, but it may also be problematic for your microbiome, warns Cohen. “You risk making the same meals, with the same ingredients, on repeat, missing out on the diversity in your diet that’s essential for gut health.” There are hundreds of species of microorganisms populating the microbiome, and they all need to feast on different foods.

But don’t quit meal prepping just yet. “Having go-to recipes up your sleeve is smart – just add one or two new meals to your repertoire each week,” she suggests. “Or get vegetable boxes delivered to your door – it challenges you to cook with seasonal produce you wouldn’t normally buy.”

Embrace elderberry

According to a study published in Nutrients, drinking around 350 millilitres of elderberry juice daily may boost microbiome health and even the body’s fat-burning ability. Researchers put this down to elderberry’s high concentration of anthocyanins, a compound which also makes plant foods purple or deep red. 

Um, can’t find elderberry juice at your local supermarket? No worries. “[The compound is] present in blueberries, blackberries, raspberries and strawberries,” says Cohen. “Adding frozen mixed berries to a smoothie is a simpler and more affordable way to get similar benefits.” Better gut health to go? Sign us up.

Get rid of excess gas

As per one of the quirkier social media trends to emerge in 2024, taking a ‘fart walk’ after dinner could relieve gas and bloating, explains gastroenterologist and Associate Professor at Western Sydney University, Dr Vincent Ho. “Walking increases internal abdominal pressure… this helps to expel gas out of the colon, similar to gently squeezing a balloon to push out air.”

A spin on the stationary bike or some yoga stretches will have the same effect. “Many people find a yoga pose called Apanasana, in which you lie on your back and hug your knees close to your chest, is helpful in getting the gas out,” offers Ho. Some gas and bloating is normal, but if it’s interfering with your quality of life, chat to your doctor.

Skip the sweeteners

The artificial sweetener neotame, used in canned fruit and drinks, can damage the cells lining the intestine, reports a study in Frontiers in Nutrition. “Researchers also found 

it could damage good bacteria in the gut microbiota,” adds Ho. 

Another common type of sweetener, erythritol, can cause digestive issues in some people, says Weaver. If pressed to pick, she’d opt for natural sugar over artificial sweeteners. “It’s not sugar itself that’s the problem, it’s the amount of sugar we’re consuming,” she says. “The World Health Organization says it’s OK to have six teaspoons of added sugar per day, but in recent years Australians have consumed, on average, 35 teaspoons of added sugar per day.” 

So check the labels of your groceries before adding to cart, and be wary of any ingredients that you don’t recognise.