why fibre matters: the science behind gut health
Conversations around health have long been dominated by protein, which is widely recognised for its role in building strength. More recently, there has been a shift towards more balanced ways of eating, alongside growing awareness around gut health, with fibre taking centre stage.
Our nutritionist, Dr Emma Astaire [MBChB MSc ANutr], explains that while protein still plays an important role, fibre may deserve a bit more attention, “especially when around 90% of the UK population aren’t meeting the recommended fibre intakes,” she notes.
Here, Dr Emma breaks down the science behind fibre, its benefits for gut health and why it deserves a more central role in our diets.
what is fibre actually?
“Dietary fibre is a type of carbohydrate that is not digested in the small intestine. Instead, it travels to the large intestine, where it is fermented by our gut bacteria.
There are different types of fibre – soluble and insoluble – which have distinct roles in the body. Soluble fibre absorbs water, helping to soften stool. Some forms, such as resistant starch, are highly fermentable and are broken down by gut bacteria to produce short-chain fatty acids. Insoluble fibre adds bulk to stool and helps food move through the digestive system, supporting regular bowel movements.”
why fibre matters more than you think
“Fibre plays a central role in digestive health. It supports regular bowel movements, reduces constipation, and nourishes beneficial bacteria in the gut.
When fibre is fermented by gut bacteria, it produces short-chain fatty acids such as butyrate, which help strengthen the gut lining and support its barrier function. Around 70% of the body’s immune cells are located in the gut-associated lymphoid tissue (GALT), highlighting the close connection between gut health and immune function. By eating fibre, we feed our gut bacteria, supporting a diverse and healthy microbiome, which in turn helps maintain immune health.
Fibre is also linked to reduced gut inflammation and improved overall metabolic health. Additionally, it supports satiety – the feeling of fullness after a meal – which can help regulate appetite.
Beyond gut health, fibre contributes to blood sugar balance. Soluble fibre slows the absorption of glucose, helping to reduce spikes and crashes in energy levels. Higher fibre intakes are also associated with improved heart health, including lower LDL-cholesterol levels.”
simple ways to get more fibre every day
“Fibre is fermented by gut bacteria, so increasing intake too quickly can lead to gas and bloating. Gradually introducing fibre helps to reduce abdominal discomfort.
Include fibre across all meals rather than front-loading it at breakfast or leaving it until the end of the day. Increasing your fluid intake alongside fibre is also important, as water helps it move comfortably through the digestive tract.
Nutrition labels can guide your choices:
- A food item is high in fibre if it contains >6g per 100g
- A food item is a source of fibre if it contains >3g per 100g
high fibre foods that can be easily added to meals
- Chickpeas, lentils, beans
- Kiwi, pear, and plums
- Cabbage and other cruciferous vegetables
- Oats, brown or red rice
- Wholegrain bread
- Nuts, chia seeds, and flaxseeds
It does not have to be complicated. At the start of each meal, simply ask -“What can I add to this meal to increase the fibre amount?”
