Back in the 1980’s, fibre was very much in-vogue thanks to Audrey Eyton’s F-Plan high fibre diet. But, over the past three decades fibre has been seen as ‘brown, beige and boring’, and so took a backseat, as other nutrients moved in to take centre stage. Now, once again, it’s time to put this so-called ‘Cinderella nutrient’ back in the nutrition spotlight, and for good reason!
While most people know that fibre helps ‘keep us ‘regular’, it has only been in recent years, since gut health burst into the health and wellbeing limelight, that our understanding and appreciation of fibre for our physical health and mental wellbeing, has strengthened considerably. So in this blog, dietitian and nutrition consultant to VSL#3, Helen Bond puts the spotlight on fibre and takes a look at what exactly fibre is, why it’s so beneficial for our gut and overall health, how much fibre we should be eating, and perhaps more importantly, how can we make sure we’re eating enough of it in our diet?
First off, what exactly is fibre?
Basically, fibre is a type of plant-based carbohydrate that, unlike other carbs, cannot be digested or absorbed in the small intestine and so continues its journey down to our large intestine, where it provides a feast for our community of trillions of microbes that have set up home within it (AKA our gut microbiota), as well as having lots of other positive effects. But, more about those later....
Different Types Of Fibre
There’s not just one, but lots of different types of fibre. In fact, there’s estimated to be around 100 types of fibre across each of the six plant-based food groups (fruits, vegetables, wholegrains, legumes (such as peas, beans and lentils), nuts and seeds) and include non-starch polysaccharides, lignin, non-digestible oligosaccharides and resistant starch.
Soluble and insoluble fibre
Historically, fibre has always been split into either ‘soluble fibre’ or ‘insoluble fibre’ and although these terms are still being used today, they’re little out-dated. It’s now thought to be more accurate to talk about fibre according to its viscosity (can it absorb water) and fermentability (can our gut microbes use it as food).
Certain types of fermentable fibres (known as prebiotic fibres), such as inulin, galacto- and fructo-oligosaccharides, are particularly useful for our ‘friendly’ gut microbes and act as a sort of fertiliser, helping them to grow, multiply and work at their best. They occur naturally, forming part of the fibre content of a wide variety of plant foods, such as bananas, apricots, dates, onions, asparagus, artichokes, leeks, almonds, chickpeas. However, while most prebiotics are types of fibres, not all fibres are prebiotics, so to help maintain the balance, integrity and diversity of our microbe community (and don’t forget, higher gut microbe diversity is associated with better health!) it’s good to eat more fibre, and a get wide variety of different fibres in our diet.
It is noteworthy that the most common classes of prebiotics are also FODMAPS (Fermentable, Oligo-, Di-, Mono- saccharides and Polyols), which may add to irritable bowel syndrome (IBS) symptoms in people that are sensitive to them!
Why is fibre so good for us?
Feeds our gut good bugs
Famished gut microbes are linked to poorer health, and when we eat a fibre poor diet our gut microbes basically go short of food. Even though we humans can’t digest fibre, our little helpers down there have the amazing ability to breakdown or ‘eat’ some types of fibre (especially fermentable prebiotic fibres and resistant start) and transform it into beneficial compounds called short chain fatty acids (such as acetate, butyrate and propionate), with all sorts of potential health benefits for us - from supporting our gut immune system, strengthening our gut barrier, reducing inflammation in our body and even acting as communication agents between our gut and other organs, like our brain. So it’s really in our best interests to boost our fibre intakes and top up our gut microbes food supply every day.
Aside from feeding our gut microbiota, fibre has structural and physical properties that benefit our health, too. Viscous fibres have the skill to soak up and hold water, forming a gel like consistency in our gut. This helps to bulk out our stools, gives our gut muscles something to really work with, and makes them easier to pass. This gel can also bind to excess cholesterol, and in turn, helps to reduce blood cholesterol levels. And, because viscous fibres slow down the time it takes food to pass through the digestive system, it helps with blood sugar spikes and keeping us feeling fuller after meals too.
Helps manage Irritable Bowel Syndrome (IBS)
Sufferers with IBS are usually well aware that diet can play an important part in controlling symptoms, and are often advised to adjust the fibre content of their diet. The British Dietetic Association (BDA) recommends that if symptoms include constipation then gradually increasing fibre intake may help, particularly wholegrains, oats, fruit, vegetables and linseeds, as these may help to soften stools and make them easier to pass. However, if symptoms include diarrhoea, it may be helpful to try reducing intake of some high fibre foods such as wholewheat breakfast cereals and breads. Have a look at the BDA IBS and Diet: Food Fact Sheet here
However, there is no "one-size-fits-all" diet for people with IBS. If you need tailored dietary advice, ask your GP to refer you to a Registered Dietitian experienced in gastroenterology or find one privately at https://freelancedietitians.org/
Lowers our risk of disease
So, fibre is a must if we want to take good care of our gut health and our gut microbiota, but fibre also benefits our overall health from the inside out. The results of a scientific review published in one of the world’s leading medical journals, The Lancet, suggest people with the most fibre in their diet are up to 30 per cent less likely to die early or suffer with coronary heart disease, stroke, type 2 diabetes and bowel cancer than those who have the least, so it’s vital we get the message out there that fibre is a nutrient not to be taken lightly.
How much fibre do we need?
UK Government health guidelines suggest a daily fibre intake of 30g for all adults (and less depending on age), but sadly only 9 per cent of us reach this target. According to UK dietary surveys adults are on average, only managing 19.7g. So, most of us need to be increasing our fibre intake to give our good gut microbes the fodder they need!
Recommended intakes of fibre are shown below:
Recommended intake of fibre
(grams per day)
Children 2- 5 years
Children 5-11 years
Children 11-16 years
Adolescents 16-18 years
Getting the right fibre types
There’re no specific guidelines on the right mix of fibre types to get our daily 30g quota, but fibre variety is also key, as there’s some evidence suggesting that different types of fibre effect our gut microbe communities differently, and in turn, could give us different health benefits.
Boost your fibre intake
So, what should we be eating to up our fibre intake? The easy solution is to gradually move over to the ‘dark’ side and swap out refined ‘white’ carbs for wholegrain or higher fibre varieties, such as brown rice, oats, wholewheat pasta and wholemeal bread, as well as enjoying at least five portions of ‘skin on’ fruit and vegetables, more legumes and pulses, and nuts and seeds, too.
Go up gradually
Gradually increase the amount of fibre in your diet, rather than trying to get the 30g all in one go – you may feel a little ‘windy’ or ‘bloated’ when you first increase fibre, but this usually passes as your body and gut microbes gets used to a higher intake. And don’t forget to top up your fluid intake at the same time, to help things move along. Check out my other tips for getting more gut healthy fibre:
Ten tips for increasing our fibre intakes
- Put carbs back on the menu, and then make the switch to wholegrains e.g. wholewheat pasta, whole barley, bulgur wheat, brown rice and diversify your grains to include ancient varieties like quinoa, freekah and buckwheat.
- Add pulses - like beans, lentils or chickpeas to bulk out summer salads, hearty casseroles, soups and curries.
- Have at least five portions of fruit and veg a day – and enjoy fresh, frozen, dried and canned – and keep the skins on, where possible.
- Choose a high fibre cereal at breakfast e.g. porridge and wholewheat cereals like Shredded wheat, Weetabix or wholegrain muesli, and top with nuts, seeds and fresh fruit for an extra fibre punch.
- Ditch white varieties and swap for wholemeal and seeded wholegrain breads, wholewheat pittas and tortilla wraps instead.
- Go for potatoes with skins on e.g. baked potato, wedges or boiled new potatoes.
- Use wholemeal, oat flour or buckwheat flour in baking, or as a compromise 50/50 white to wholemeal flour.
- Trading in those crisps, chocolates and biscuits for some wholegrain popcorn with a sprinkling of cinnamon, dried fruit, oatcakes and peanut butter or a handful of unsalted nuts.
- Increasethe amount of resistant starch (that’s fibre) in potatoes, rice and pasta by cooling them after cooking and reheating them later.
- Look at back-of-pack food labels for detailed nutritional information. Remember to make a claim to be high in fibre, the food product has to contain 6g of fibre per 100g, or 3g per 100g to be a source of fibre.
At a glance guide to some fibre containing foods
- 2 breakfast wheat biscuits – 3.8g
- 30g bran flakes – 5g
- 40g raw oats – 3.6g
- 170g cooked wholewheat pasta – 6.5g
- 185g cooked brown rice – 2.8g
- I slice of wholemeal bread (40g) – 2.7g
- I slice of white bread (40g) – 1g
- A handful of almonds (30g) - 3.5g
- A handful of walnuts (30g) – 1.4g
- ½ can of baked beans (207g) – 7.7g
- ½ can of chick peas (200g) – 8.3g
- One banana (150g) – 2.1g
- One apple (150g) – 2.4g
- A handful of pumpkin seeds (25g) - 2.2g
- 80g (3 heaped tablespoons) broccoli – 2g
- 80g carrot batons – 3.1g
- One tomato (80g) - 0.8g
- One medium (180g) baked potato (with skin) – 4.7g
We still have much to learn about the benefits of fibre, and how the different types could positively benefit our gut microbiota, but for those of us striving to feel good, and improve our health and wellbeing, simply eating more plant-based foods that are rich in fibre, is a good place to start!
The content of this blog is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your GP, Pharmacist or another health professional, if you’re struggling with gut symptoms, you’re pregnant, on medication or you have a medical condition that means you’re immune suppressed and wanting to boost your friendly gut microbe community with VSL#3.
- Scientific Advisory Committee on Nutrition (2015). Carbohydrates and Health. Public Health England, London. Available at: https://www.gov.uk/government/publications/sacn-carbohydrates-and-health-report Accessed April 2021.
- Public Health England. National Diet and Nutrition Survey. UK Results from Years 9-11 of the Rolling Programme (2016/17-2018/19). Available at https://www.gov.uk/government/statistics/ndns-results-from-years-9-to-11-2016-to-2017-and-2018-to-2019.
- Dr Megan Rossi, Dr Eirini Dimidi (2017). Fibre and Health Fact Sheet.
- Hopper B, Spiro A, Stanner S (2015). 30g of fibre a day. An achievable recommendation? Nutrition Bulletin 40 (2) 118-129.
- Fibre. BDA Food Fact Sheet (2016). Available at: https://www.bda.uk.com/resource/fibre.html Accessed April 2021.
- IBS and Diet. BDA Food Fact Sheet (2016). Available at: https://www.bda.uk.com/resource/irritable-bowel-syndrome-diet.html
- Reynolds A, Mann J, Cummings J et al (2019). Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. The Lancet volume 393, Issue 10170, P434-445. Available at https://doi.org/10.1016/S0140-6736(18)31809-9 Accessed April 2021.
- Slavin L. Fiber and prebiotics: mechanisms and health benefits (2013). Nutrients (5 (4) 1417-35.
- Rossi M (2019). Eat Yourself Healthy. Penguin, Random House, UK.
- Jefferson A (2019). Give your friendly gut bacteria a helping hand. British Dietetic Association.