The health benefits of prebiotics and how to make the most of them, explained by experts

You’re probably familiar with the term prebiotics – it’s been a buzzword in the health and wellness industry for some time now. However, the role pf prebiotics in gut health is still often misunderstood, with many people still not entirely sure what prebiotics do.

Prebiotics play an important part in supporting gut health as they serve as nourishment for the gut, working to keep it calm, comfortable and functioning properly. Your body can’t naturally digest prebiotics, so they’re able to pass intact through the digestive system to the colon, where they become food for your gut bacteria.

This in turn leads to improved digestive wellbeing and a balanced and resilient gut microbiome, which is the densest and most diverse microbial community in the body, housing trillions of non-harmful bacteria, viruses and fungi.

“Prebiotics are a type of fibre that feed the beneficial bacteria already living in your gut,” explains nutritionist Milena Kaler. “Unlike probiotics, which introduce new bacteria, prebiotics help strengthen your gut microbiome and its existing good bacteria.”

‘Good’ bacteria living in your gut include the species Bifidobacterium – which helps digest fibre and prevents gut infections – and Lactobacillus – which helps to keep the gut barrier strong. Prebiotics help both of these strains of bacteria to grow, leading to a healthier, more balanced gut.

Studies show that approximately 70-80 per cent of immune cells live in the gut, which means you’re more likely to fight off colds and stay well if you keep these cells well fed with prebiotics.

So how do you increase your prebiotic intake? You can of course take a prebiotic supplement, but most experts agree that the best source of prebiotics is a healthy, balanced diet. As nutritionist Kate Garden explains: “prebiotics can be found in various foods, such as fruits, vegetables and whole grains, like oats, brown rice and quinoa.”

“Prebiotic supplements can also be safely consumed by those with specific dietary restrictions or allergies, including those with a gluten or lactose intolerance,” she adds.

In fact, the majority of people can benefit from taking prebiotics, but it’s best to take them when your gut is stable – meaning you’re not currently experiencing constipation or diarrhoea. And if you have any underlying gut medical conditions you should always check with your doctor or a gut health specialist before taking them.

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Nutritionist Ben Mountifield says that two of the main prebiotics to know are inulin and fructo-oligosaccharides (or FOS), which you can get naturally from foods such as chicory root, onions and Jerusalem artichokes. They are also frequently used in fibre supplements and health drinks like sodas with added fibre.

“There’s also galacto-oligosaccharides (or GOS) from dairy, beta-glucans from oats and certain mushrooms like shiitake, reishi and oyster and polyphenols from colourful plants, olive oil, and cacao,” he comments.

Garden also advocates for consuming a type of prebiotics known as resistant starches. “You can find these in green bananas, rice, beans and cooked and cooled potatoes. Also look for pectin – a prebiotic and soluble fibre found in the cell wall of lots of fruits and vegetables, and saponins, found in oats, onions and legumes.”

A diverse diet means a diverse range of fibres and nutrients that act as fuel for different microbial species in your gut, helping them to thrive and maintain a healthy, balanced microbiome.

Mountifield explains that you only need to look back in history to see how long prebiotics have been in our diet. “Our hunter–gatherer ancestors consumed prebiotic fibres, and far more than we do today – often upwards of 50-100g daily – which also highlights how modern diets fall short in supporting microbial diversity.”

Kaler points out that eating prebiotic foods regularly can support digestion, enhance immune function and improve mineral absorption, which contributes to stronger bones and muscles, as well as increased energy. “Prebiotics help your beneficial bacteria to produce compounds that reduce inflammation and maintain gut lining health. Emerging research also links a healthy microbiome with improved mood and mental wellbeing,” she says.

In addition to supporting your mental health, Garden explains that prebiotics show promising results when it comes to reducing cognitive decline and the impact of neurodegenerative diseases. “Prebiotics can help to improve communication between the gut and the brain, as well as promote the production of protective compounds that contribute to brain health.”

Garden adds that pregnant and lactating women may also benefit from prebiotic supplements. “There is some limited evidence to suggest that prebiotics may help reduce the risk of allergic diseases in babies, although it is especially important to consult with a healthcare professional before taking any supplements during pregnancy or lactation.”

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Prebiotics are largely beneficial but they aren’t suitable for everyone, especially for those with IBS or SIBO – small intestinal bacterial overgrowth. Since prebiotics act as food for gut bacteria, they can sometimes make symptoms like bloating, gas or abdominal pain worse by causing more activity in the gut.

“Those with gut conditions like IBS or SIBO may find that they can’t properly tolerate prebiotics until underlying dysbiosis (a disparity of beneficial gut bacteria) is addressed,” says Mountifield. “In these cases, introducing prebiotics can worsen symptoms, as it’s feeding bacteria that’s in the wrong location in the gut.”

You can also have too much of a good thing. If you take more than the suggested amount of prebiotic supplements, you’re likely to experience digestive discomfort such as gas or bloating, so always follow the recommended dosage on the label.

“Prebiotics should be introduced with a ‘low and slow’ method once digestion and gastrointestinal motility are supported. When introduced at the right time, they can help restore a diverse, metabolically active microbiome, which is one of the foundations of long-term health,” says Mountifield.

The takeaway? Incorporating prebiotics into your diet and lifestyle can contribute to your overall health and wellbeing, improving digestion, enhancing absorption of nutrients and lessening any bacteria contributing to bloating, inflammation or discomfort.

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