Are fibre supplements just as effective as naturally fibre-rich foods? And can fibre really help regulate appetite? We asked Gastroenterology Dietitian Dr Sammie Gill to explain.
1. Fibre supports heart health
Fact: The benefits of fibre extend throughout the body and way beyond gut health, supporting important organs, like the heart.
For example, soluble and viscous fibres (e.g. beta glucans found in oats) are known for their cholesterol lowering effects. They do this by trapping bile acids which limits how much cholesterol can be absorbed by the gut.
On the other hand, fermentable fibres – like prebiotics and resistant starch - can function as ‘food’ for gut microbes in the large intestine. In return, gut microbes release thousands of different compounds, including short chain fatty acids (SCFAs). A proportion of these can be absorbed and travel around the body, acting on other vital organs, including the heart.
For example, studies in animals and humans have shown that SCFAs can reduce total cholesterol and LDL ‘bad’ cholesterol levels by lowering the rate of cholesterol production in the liver. Furthermore, several animal studies have shown that SCFAs can regulate blood pressure by binding to receptors that line the blood vessel walls.
2. All fibre is the same
Fiction: It’s not only the amount of fibre that matters – the variety is just as important. This is because each fibre type serves a different role in the body.
There are many different types of fibre – cellulose, pectin, resistant starch, and prebiotics like galacto-oligosaccharides (GOS) and fructo-oligosaccharides (FOS).
That’s why eating a wide range of plant-based foods is recommended. Greater plant diversity means a broader spectrum of fibre types.
What’s more, different gut microbes have ‘preferences’ for different fibres. Consuming a diverse range of fibre types from many different plant-based sources helps to ensure different communities of microbes are well fed and have all they need to function optimally.
3. Fibre helps with appetite
Fact: Fibre regulates appetite by:
- decreasing chewing and eating speed
- delaying stomach emptying
- delaying absorption of nutrients, including glucose
- stimulating satiety (fullness) hormones, including cholecystokinin, glucagon-like peptide-1 (GLP-1), and peptide YY
What’s more, research suggests that SCFAs produced in the large intestine can regulate appetite by activating receptors on gut cells, which in turn, stimulate the release of satiety hormones.
Labs studies suggest that both soluble, viscous fibres (which swell by absorbing water) and insoluble, non-viscous fibres (which add bulk and weight to poo) in the last part of the small intestine (called the ileum) may trigger what’s called the ‘ileal brake’ – a braking mechanism which slows the movement of food through the gut and reduces gut secretions. down the passage of food digestion and reduces gut secretions.
4. Fibre only matters if you’re constipated
Fiction: While fibre is often highlighted for its role in relieving constipation, it shouldn’t be viewed as a nutrient with just one function. Fibre offers whole-body health benefits. It’s a true all-rounder, contributing to health in a wide range of ways.
For example, for every 7g daily increase in fibre (half a can of baked beans), you lower your risk of cardiovascular disease by 9%, stroke by 7%, type 2 diabetes by 6%, and colorectal cancer by 8%.
Another landmark study backed this up showing that that a fibre rich diet reduces the risk of heart disease, stroke, type 2 diabetes and colon cancer by 16-24%.
5. Most people don’t get enough fibre
Fact: In the UK, 96% of people are deficient in fibre and not meeting the recommended 30g a day, with most consuming only about half of that.
Recent trends like ‘fibremaxxing’ have brought fibre into the spotlight, highlighting it as a nutrient that deserves more attention.
Making small tweaks can help you reach your fibre goals. For example:
- Throw in a tin of beans to any pasta-based dish.
- Keep the skins on all fruit and vegetables (except the ones you can’t e.g. pineapple, bananas).
- Make your own meatballs with added oats.
- Load up pizza with veggies.
- Make your own smoothies – think frozen fruit, nut butters, nuts, seeds…
- Go for food products that say ‘whole’ on the label (e.g. wholegrain, wholemeal, wholewheat).
- Add a handful of nuts or seeds to salads, yogurt, sauces, rice, stir-fry…
- Keep high-fibre snacks to hand such as popcorn, dried fruit, wholegrain crackers with nut butter…
- Choose a high fibre breakfast such as porridge, wheat biscuits, shredded wheat, or wholegrain toast with chia seeds added to your jam.
- For the chocolate lovers, try dipping fruits into melted dark chocolate, drizzle chocolate on fruit-filled crepes, or try chocolate avocado mousse.
6. More fibre is always better
Fiction: There are no downsides to eating more fibre. But, if you’re not used to eating lots of fibre-rich foods, it’s important to build up gradually to give your gut time to adapt and to minimise mild gut symptoms, such as bloating or wind.
For example, you could start by adding some lentils to a bolognaise or throwing some chopped vegetables into a tomato-based pasta sauce.
For certain groups, such as people with irritable bowel syndrome (IBS), tolerance to type and amount of fibre can vary. It’s important to work with a registered dietitian who can support with managing symptoms and maintaining fibre.
For example, if you’re struggling with constipation, adding more fibre if you’re already backed up is unlikely to be effective. Fermentable fibres can worsen bloating, if you’re constipated.
Certain types of fibre can be helpful for constipation, such as psyllium can be effective. Try psyllium at a dose of 10g/d for at least 4 weeks. Start low and go slow. Try half a tablespoon per day for the first week, a full tablespoon per day for the second week, and gradually increase until you reach around three tablespoons per day.
7. Fibre is ‘food’ for your gut microbes
Fact: although it depends on the type of fibre.
Fermentable fibres – such as prebiotics and resistant starch – are ‘food’ for gut microbes. These fibre types are readily broken down.
On the other hand, some fibres are poorly fermented – such as psyllium or cellulose. These types of fibres play a different role in gut health, like increasing poo weight and improving poo consistency.
8. Fibre supplements are just as effective as naturally fibre-rich foods
Fiction: Fibre supplements aren’t comparable to whole foods that naturally contain fibre – the richest sources being plant-based foods, like wholegrains, nuts, seeds, legumes, fruit and vegetables.
The main difference is that fibre supplements only provide fibre – either just one type or a small mix of a few types.
Whereas plant-based foods contain a unique and complex mix of many different fibre types. They also contain thousands of phytochemicals (such as polyphenols). It’s thought 90-95% of polyphenols also make their way to your gut microbes, providing them with another valuable source of ‘food’.
Basically, you’re getting far more bang for your nutritional buck with plant-based foods versus fibre supplements.
That said, fibre supplements do have their place - like if you’re struggling with diarrhoea or constipation. In these cases, targeted fibre supplements to help manage certain symptoms can be very effective.
9. Fibre isn’t digested
Fact: The body is equipped to digest most nutrients, producing digestive enzymes that break down the food you eat so it can be absorbed and used. But fibre is different.
Humans lack the digestive enzymes needed to break it down making it resistant to digestion in the small intestine. As a result, fibre travels through the gut largely intact, delivering its health benefits along the way.
Looking for more fact v fiction?
Fact v fiction: The science of sharing microbes
Fact v fiction: Poo 101 what’s ‘normal’ anyway?
To learn more about other gut health topics, visit Symprove’s Gut Hub.
Sources
Are all fibres created equal with respect to lipid lowering? Comparing the effect of viscous dietary fibre to non-viscous fibre from cereal sources: a systematic review and meta-analysis of randomised controlled trials. (2023). Link.
Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. (2019). Link.
Dietary fiber intake and gut microbiota in human health. (2022). Link.
Dietary management of chronic constipation: a review of evidence-based strategies and clinical guidelines. (2025). Link.
Role of fermentation-resistant and nonfermentable fibers in gastrointestinal health: mechanisms, benefits, and challenges. (2026). Link.
SACN Carbohydrates and Health Report. (2015). Link.
The role of dietary fibers in regulating appetite, an overview of mechanisms and weight consequences. (2024). Link.
