what is prebiotic fibre?

What is prebiotic fibre?

You most likely have heard of probiotics, but what are prebiotics and why are they so important in gut and overall health?

In this blog we are going to explore:

  • Why prebiotic fibre is essential for health
  • The gut microbiome
  • Foods prebiotic fibres are in
  • How prebiotic fibre works
  • Health benefits of prebiotic fibre
  • Prebiotic fibre intake hack

Why is prebiotic fibre essential? 

Prebiotic fibre is an essential and special type of dietary fibre that promotes the growth of beneficial bacteria in the gut, also known as gut flora.

Unlike probiotics, which are live microorganisms that provide health benefits when consumed, prebiotic fibres are not living organisms, but rather indigestible carbohydrates that serve as food for the bacteria that live in our intestines.

Probiotics on their own have a limited effect because they’re easily destroyed.  For probiotics to flourish, they need the right food to feed on – and that’s where prebiotics come into play.

What is the gut microbiome?

The gut microbiome is a complex ecosystem made up of hundreds of different species of bacteria, fungi, viruses and other microorganisms. These microorganisms play a crucial role in our overall health and well-being, as they help to regulate our immune system, produce essential vitamins and minerals, and aid in the digestion of food.

A healthy gut microbiome is essential for good health, and prebiotic fibres play a key role in maintaining a balanced and diverse gut microbiome.

gut microbiome is like a pond

Think of your gut microbiome as a pond. The fish as probiotics. Their special food the prebiotics.  Happy, healthy fish, fed with the right food, supports a happy, healthy pond that flourishes!

What foods are prebiotic fibres in?

Prebiotic fibres are found in various foods, including whole grains, legumes, vegetables, and fruits such as onions, garlic, leeks, bananas, asparagus, dandelion greens and Jerusalem artichoke.

However, you would have to eat a lot of these foods to gain any benefit, as the recommended prebiotic fibre intake is 3-5g daily. For example, you would need to eat 7 bananas or 2 onions to get your daily intake of prebiotic fibre.

(There is an easy prebiotic fibre hack mentioned down below that provides 100% of daily prebiotic fibre, easily and enjoyably!).

 chicory root fibre

The number one source that's high in prebiotics is chicory root fibre (inulin). Approximately 68% of chicory root fibre comes from the prebiotic fibre, inulin. Other commonly consumed prebiotic fibres are fructo-oligosaccharides (FOS), and galacto-oligosaccharides (GOS).

Further reading: 19 healthy prebiotic foods

How does prebiotic fibres work?

how prebiotics work

Health benefits of prebiotic fibre

One of the benefits of consuming prebiotic fibres is improved digestion. The fermentation process that takes place in the gut as a result of prebiotic fibre consumption helps to break down food more effectively and reduce the symptoms of digestive disorders such as constipation, bloating, and diarrhea.

Prebiotic fibre takes dietary fibre to the next level regarding health benefits.

In addition to all the health benefits that increased dietary fibre offers, such as promoting cardiovascular health, prebiotic fibre takes health to the next level.

There are over 4,000 scientific papers showing how prebiotic fibre can aid with a wide range of health benefits.

Let's look at some of these health benefits a bit further...

Immune system function

Most people aren't aware that approximately 70% of their immune cells are found in the gut! (1)

The gut microbiome is closely linked to the immune system, and a healthy gut microbiome can help to prevent illness and disease. Prebiotic fibres help to promote the growth of beneficial bacteria in the gut, which can improve the function of the immune system and reduce the risk of autoimmune diseases.

Mental well-being

Approximately 95% of serotonin, the 'happy hormone' is produced in the gut. (2

The gut microbiome plays a role in the production of neurotransmitters such as serotonin and dopamine, which are important for regulating mood and emotions. By promoting a healthy gut microbiome, prebiotic fibres can help to improve mood, reduce anxiety and depression, and promote a positive outlook on life.

If you or someone you know is challenged by anxiety and depression, improving gut health can make a positive difference. 

Find out more about gut health and mood here.

Weight management

Prebiotic fibres are also beneficial for weight management. Chicory root fibre (inulin) is scientifically proven to significantly promote weight loss and ectopic fat reduction (3)

By improving digestion and promoting a healthy gut microbiome, prebiotic fibres can help to regulate appetite and reduce the risk of overeating. Additionally, they can help to increase feelings of fullness and satisfaction, making it easier to stick to a healthy diet. 


Our research found that when 41 participants drank one bottle of  fibrewater daily for 12 days (one case), that 73% of people reported not needing to eat as much at mealtimes, and 61% snacked less and felt more satiated. 

Find out more about prebiotics and weight management here.

Regulates blood sugar levels and reduces the risk of developing type 2 diabetes

Prebiotic chicory root fibre (which is what we use in  fibrewater) has an authorised UK and EU health claim for lowering and slowing blood glucose rise. (4)

Promotes digestive health

As prebiotic fibre is also dietary fibre, increasing fibre in general is proven to support digestive health. Due to feeding healthy gut bacteria (probiotics) and fermentation, prebiotics and healthier digestive health go hand-in-hand. (5) (6)


If this wonder fibre didn't already do enough amazing things for our health, prebiotic fibre has been found to positively impact sleep.  And chicory root fibre is in fact a known mild sedative. (Yes! You can still operate machinery and have chicory root fibre!).(7)

Find out more about prebiotics and sleep here.

Skin health

Believe or not, not only is there a gut-brain axis, there is a gut-skin axis, too.  There is a growing body of research that suggest a direct connection between gut health and skin problems, such as eczema, rosacea, psoriasis - even acne.  And prebiotics can help! 

Find out more about Prebiotics: The connection between gut health & skin problems

Prebiotic intake hack!

io fibrewater prebiotic fibre

One easy (and delicious!) way to boost your prebiotic fibre intake is by drinking fibrewater, which not only delivers 100% of your daily intake of prebiotics, it also provides 20% of your daily fibre intake.

Plus, ió fibrewater is made with no added sugar, no 'nasty' ingredients such as artificial sweetener, and is a great swap-up from your usual drinks to something that is functional. 

In a 12-day challenge, people drinking one bottle of ió fibrewater experienced significant improvements.*

Our research found:

 fibrewater comes in Lemon & Lime and Strawberry flavours. And it tastes refreshingly delicious, too! :)

Scientifically proven

In addition to the thousands of studies on prebiotics and their positive impact on people's health, the prebiotic fibre (chicory root) that we use in fibrewater has two authorised UK (GB NHC) and EU (EFSA) health claims for:

  1. Slowing and lowering blood glucose rise
  2. Supporting proper gut function

Furthermore, Glasgow Caledonian University (GCU) studied  fibrewater and found that it increased healthy gut microbes (probiotics) significantly.

Glasgow Caledonian University io fibrewater prebiotic fibre study

Within 48 hours S. Boulardii increased by 4 million percent and B. Coagulans by 25,000 percent compared to regular flavoured water.  Both of these microbes are proven to have a positive impact on digestive health as well as immune system function.

You can read the GCU press release here.


In conclusion, prebiotic fibres are an important component of a healthy diet. They take dietary fibre to the next level with a wide range of proven health benefits.

Prebiotic fibre promotes the growth of beneficial bacteria in the gut, improve digestion, boost the immune system, support mental health, and aid in weight management.

To incorporate more prebiotic fibre into your diet, it is recommended to include a variety of whole grains, legumes, vegetables, and fruits in your diet.

By consuming a diet rich in prebiotic fibres, and dietary fibre, you can support a healthy gut microbiome and enjoy the health benefits that come with it.

ió fibrewater is available to buy on our online shop or on Amazon.  GET a 15% discount by using the code 'PREBIOTIC15' on your next order!

gut health prebiotics

 *41 participants drinking one bottle of  fibrewater daily for 12 days as part of our 12 Day Challenge. Research included a baseline survey prior to drinking the water, a survey on day four and a survey on day 12.

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