30 Mar 2022
Dietary fibre is a component of plant foods that is not fully digested by our bodies. High fibre intakes in the diet lead to multiple health benefits including reduced constipation, decreased risk of developing type 2 diabetes, heart disease and colorectal cancer. In fact, the healthiest diets always include dietary fibre. Overall there are multiple types of dietary fibres which can be classified by their characteristics which include solubility, fermentability and viscosity.
The nature of each type of dietary fibre determines the specific role they play in the body.
Moreover, fibre is often categorised as either soluble or insoluble, however there are other physiochemical characteristics of fibre that we need to consider in order to understand the full spectrum of dietary fibre.
Fermentability is one of three essential properties to characterise fibre. In addition, the other two are solubility and viscosity. Fermentability is a scientific term to describe the process which occurs when fibre is broken down by the bacteria in our gut.
Fermentation takes place in our large intestine, where our gut bacteria essentially “eats” fibre and as a result, produces short-chain fatty acids and gases as by-products of the fermentation process.
If you think about how alcoholic beverages such as wine and beer are made, it involves a similar process. Put simply, alcoholic fermentation occurs when yeast uses sugar as fuel to produce ethanol, carbon dioxide and other byproducts. In fact, sugar is the fuel for yeast much like fibre is the fuel for our gut bacteria.
Dietary fibre can also be categorised based on its viscosity. Viscous fibres develop a thicker consistency when mixed with liquids. Examples of viscous fibres include psyllium, beta-glucans (found in oats, barley and fungi) and pectins (found in fruit, vegetables and legumes). When we eat viscous fibres, they form a gel like substance in our gut, this can decrease the absorption rate of certain nutrients such as glucose.
Moreover, other fibres such as cellulose (found in cell walls of green plants) and resistant starch (found in cooked and cooled starchy foods such as potatoes are non-viscous. Cellulose is also an insoluble fibre and resistant starch has very low solubility in water. However, these types of fibres play a different role in the body from viscous fibres. In fact, they add bulk to our stool and help keep our bowel movements regular. (1)(2)
Sources of low fermentable fibre (for example, cellulose found in all leafy greens) help prevent constipation by adding bulk to stool. It is important to ensure that you are getting enough fluid intake to go accompany your fibre intake. In addition, low fibre diets have been linked to conditions such as diverticulitis and in the worst cases, colorectal cancer. Diverticulitis occurs when pouches form inside your intestines and become inflamed or infected. A fibre-rich diet will keep your gut in good shape!
Some fermentable fibres such as beta-glucans found in oats have been found to reduce cholesterol levels. In fact, a review of the scientific literature found that an intake of at least 3g per day of oat beta-glucans may reduce total cholesterol and LDL (bad) cholesterol levels by up to 10% in both people with high cholesterol and normal cholesterol.(3)
Moreover, dietary fibre intake can improve glycaemic control and plays a crucial role in the management of type 2 diabetes. In fact there is evidence to show that high intakes of dietary fibre play a preventative role in reducing the risk of developing type 2 diabetes. Overall, a fibre-rich diet has also been shown to increase satiety and delay the onset of hunger.(4)(5)
In the UK, most people are averaging about 18g of fibre per day, this is well below the recommended 30g/day for adults. Children need less fibre than adults although even they are not hitting their daily targets. Younger children between 2 and 5 years of age require approximately 15g/day, 5 to 11 year olds require roughly 20g/day, and older children (11 to 16 years) require 25g/day.
Fibre is naturally abundant in a large variety of foods, particularly fruits, vegetables and whole grains.
Eat more fruits and vegetables - fruits and vegetables are some of the highest natural sources of fibre! Not only are they full of essential vitamins and minerals, they will also help keep your gut in top condition thanks to their fibre content. Remember that drinking fruit juice is not the same as eating whole fruit because you are often missing out on all the gut-friendly fibre!
Fibre plays a key role in ensuring healthy and regular bowel movements. However, it is only one piece of the puzzle. In order to prevent or relieve constipation, there are three main elements to consider: fibre intake, hydration levels, and level of physical activity.
It is possible that someone who consumes adequate amounts of fibre yet is not getting adequate hydration, and leads a sedentary lifestyle, may suffer from constipation.
In fact, increasing your fibre intake without also increasing your fluid intake can lead to constipation. Make sure you are drinking plenty of fluids throughout the day to keep your gut in check.
In addition, physical activity plays an important role in bowel regularity. It has been shown that a sedentary lifestyle and lack of physical activity can negatively affect our gut.
Aim to move your body every day, whether it’s a walk in the park or a gym class, it will benefit both your physical and mental health.
Fibre supplements come in many shapes and sizes, from powders to capsules. Some medical conditions may specifically call for a routine fibre supplement.
However, for most of us, focusing on a fibre-rich diet through an intake of healthy whole foods should be enough to meet our daily needs.
Eating plenty of whole grain cereals and breads, fruits, vegetables, nuts and seeds is a great way to ensure that you are eating a fibre-rich diet. If you’re looking for some gut-friendly fibre rich snacks, our Organic Rosemary Sweet Potato Crackers provide 12g of fibre per 100g. That’s about twice as much fibre as a regular loaf of wholemeal bread! If you’re after a sweet snack or breakfast idea, our Tigernut Granola provides 14g of fibre per 100g, which is also two times more than an average store bought granola.
Overall, if you are including plenty of fibre rich foods into your diet you likely won’t need a fibre supplement. However, if you feel like this is still not enough, check with your medical practitioner or dietitian to discuss whether a fibre supplement may be beneficial for you.
Most of us are not meeting our daily fibre needs so the main concern for the majority of people is to focus on adding more fibre to their diet.
If, however, you happen to be the exception to the rule and eat a lot of fibre, how much is too much?
There is no clear evidence to determine how much is “too much”, so we suggest listening to your body. If you are experiencing bloating, excessive trips to the bathroom, or other unpleasant gut symptoms, it may be because you have introduced too much fibre too soon.
Note that an irritable gut can also be caused by other factors so don’t assume that fibre is necessarily the culprit. Food sensitivities and intolerances can also lead to uncomfortable gut symptoms so it’s best to rule them out with your doctor or dietitian before you make any changes to your diet.
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