We think of fibre as indigestible, just passing through our system. It’s true, fibre makes it to our intestines unaffected by the digestion process where it helps support stool formation. But in fact fibre benefits extend way beyond just keeping us regular!
Our gut, in particular the large intestine, is densely populated with roughly 100 trillion bacteria
Our gut, in particular the large intestine, is densely populated with roughly 100 trillion bacteria. This is our gut microbiome – our body’s own unique ecosystem of gut flora. The health of the large intestine, the gatekeeper of the intestines, contributes significantly to our ability to digest and absorb nutrients from the food we eat.
Whilst we don’t digest fibre per se, some types of fibre do in fact provide fodder for certain gut microbia to ferment. This stimulates the growth of healthy bacteria to assist with the digestion and absorption of food also helping increase our resistance to pathogenic (bad!) bacteria.
This is known as the prebiotic effect and it’s exclusive to fibre.
But not all fibre is prebiotic, it’s only some soluble fibres that are prebiotic! Soluble fibres are fibres that can dissolve in water. The most well-researched types of soluble fibre include inulin (which belongs to a class of carbohydrates called fructans), oligofructose and fructo-oligosaccharides (FOS). All of which have been show to significantly increase the population of Bifidobacteria and Lactobacilli when consuming about 5-10g of inulin a day.[1]
What’s more, some soluble fibres do not serve as prebiotics but can still be fermented by gut bacteria, producing short chain fatty acids (SCFAs) as a by-product of the process. These SCFAs may help regulate intestinal inflammation amongst other notable digestive and health benefits.[2]
Some of my favourite fibrous foods.
Artichokes
The Jerusalem artichoke is also known as the ‘sun root’ and about a quarter of its weight is composed of inulin fibre. Traditional artichokes are more like 3-10%. A distinctive flavour, these area great with some olive oil and chilli, shaved and tossed into salads or slaws, into pasta dishes, or served as part of a mezze.
Leeks, onions and garlic
These bulbs all contain high concentrations of inulin and FOS. The good news is they are all great for building flavour so remember to add them to all your soups, sauces, curries and stews.
Asparagus
Asparagus is rich in fibre and contains a valuable amount of inulin. Enjoy succulent and tender spears with your poached eggs in the morning, add to your favourite salad or make it a main feature in your evening meals, for example, sautéd with garlic, mushrooms and chicken.
Flax seed
Flax seeds are reputed for their combination of lignans (fibre like compounds which offer antioxidant benefits), mucilage fibre and omega 3 content. ‘Mucilage’ refers to a water-soluble, gel forming fibre that provide support to the gastro-intestinal tract.
Daily use of flaxseed has been shown to improve gut bacteria and insulin sensitivity in overweight women.[3] Try flaxseed by adding a 1-2 tablespoons of milled or crushed flax seeds (linseeds) to foods or smoothies each day, or sprinkle over breakfast foods such as porridge or yogurt. You can also add to stews or incorporate in home baking recipes.
Some other fibrous foods of note are sweet potatoes, bananas, broccoli, psyllium seed husk, beans, rye and lentils.
Everyone is individual and their digestive system may respond differently to fibrous foods. Be sure to introduce new foods slowly and find the foods that work best for you!
Hungry for more? Sarah runs her business Gut Reaction from Lemington Spa.
