Summary of why fibre sources matter
- Consumers shift from fibremaxxing trends toward diverse fibre sources for health
- Different fibre types deliver distinct digestion benefits and support gut bacteria
- Soluble fibre slows sugar absorption and increases fullness through gel formation
- Insoluble fibre improves bowel regularity by adding bulk to digestive waste
- Whole‑food fibre offers added nutrients and phytochemicals enhancing gut microbiota
Fibre is, according to many, the new protein. It is certainly seeing fervent enthusiasm from some quarters, with the ‘fibremaxxing’ trend tearing through social media like wildfire.
Nevertheless, not everyone is convinced that the trend will last. According to analytics platform Mintel, the ‘maxxing’ trend is on its way out, at least when it comes to protein and fibre.
Rather than indiscriminately cramming as much of these ingredients as they can, consumers will instead look towards getting them from a diversity of sources.
When it comes to protein, discussions around the benefits of getting diverse sources and focusing on quality are already underway. What about fibre?
How different fibre sources have different nutritional benefits
It matters where consumers get their fibre from, because different types of fibre have different nutritional benefits.
“Fibre quality is usually about its source and composition – for example, whole grains, legumes, fruits, and vegetables all differ in their fibre types“, explains Corraine Toyn, registered nutritionist at marketing and nutrition consultancy Chickpea Marketing.
Different fibres have different nutritional benefits.
Soluble fibre pulls water from the stomach, turning it into a gel-like substance. This slows digestion and can boost satiety. It can be sourced from ripe fruit or oats.
The health benefits associated with soluble fibre include slowing down the body’s absorption of sugar, feeding healthy gut bacteria and lowering cholesterol, according to UCLA Health.
Insoluble fibre, on the other hand, does not dissolve in water. Its role is to bulk up stool, thus reducing the risk of constipation. This type of fibre can be found in bran, nuts, seeds or wheat.
Resistant starch, which is classified as dietary fibre, is the part of starch that is not digested in the small intestine. Instead, it is fermented in the colon by microorganisms. One study suggests that it may improve glucose tolerance and boost satiety. It is found in legumes or cooked or cooled grains.
Resistant starch can be broken down by gut bacteria into short-chain fatty acids and prebiotics, explains nutritionist Toyn.
Not all fibre does the same thing. Diversity is important.
Influence of other ingredients on fibre
As well as the type of fibre used, the ingredients used with fibre can also impact the nutritional quality of a food.
For example, fat and protein can influence the transit time of fibre in the gut, explains Toyn.
They can also have an effect on fermentation processes, which is how fibre works in the gut. According to one study, the inclusion of protein alongside fibre, and even of protein alone, can induce the production of propionate and butyrate, types of short-chain fatty acid.
The type of fibre involved was found to be important for the production of such short-chain fatty acids, as was the level of protein inclusion.
Fortification vs whole foods
While fibre naturally occurs in a great many foods, the market for fibre fortification is growing. So does it matter whether fibre is fortified, or naturally occurs in a product?
“Naturally occurring fibre in foods tends to come with a matrix of nutrients and phytochemicals, whereas fibre fortification adds isolated fibres to foods,“ says Toyn.
According to Toyn, the matrix effect (the effect on the composition of the food itself) of fibre from whole foods is more beneficial for gut health and microbiota.
