We’ve all heard it before, fibre this, fibre that. Everybody seems to know about fibre, but when specifically asked what fibre does in your body, the initial response would be…it’s good for the body. Let’s improve that, shall we?
So, what exactly is dietary fibre?
Dietary fibre is a type of indigestible carbohydrate derived from the food you eat. It’s basically a part of most plant foods that your digestive system can’t digest. Traditionally, two types of dietary fibres known as insoluble and soluble fibre were discovered. But more recently, a third type was named prebiotic. All three of these types have their health benefits. So, why do we have to eat it? We’ll tell you why.
Soluble fibre means that the fibre dissolves in water. The fibre and water combine to form a gel in your intestines that slows down your digestion, making you feel full long after eating a meal. This type of fibre can help people with diabetes mellitus to maintain normal blood sugar levels. Some types of soluble fibre such as pectin, beta glucan, guar gum and psyllium also help to lower your LDL cholesterol levels.
Insoluble fibre doesn’t dissolve in water. It adds bulk to your stools and makes your toilet habits regular and uneventful (no straining, no constipation). It gives you a smooth experience when you’re on the house throne (toilet).
A third relatively new type of fibre that was discovered more recently is called a prebiotic. Prebiotics are a special type of soluble fibre. In the simplest sense, prebiotics act as food for the beneficial bacteria residing in your large intestine. There are some requirements to be classified as a prebiotic, click here to learn what these are. Even though a prebiotic sounds very similar to a probiotic, they aren’t the same thing. To learn more about what a probiotic is, click here. Also, it’s vital to know that all prebiotics are fibres, BUT not all fibres are prebiotics. Your body needs a constant supply of prebiotics, here’s why:
Your Colon, the Fermentation Factory
Approximately 1,000 different species of bacteria live in your colon. The relative composition of the different species of bacteria differs for each person. Your colon is a like a factory, and the different species of bacteria behave as factory workers. Raw materials arrive in the form of a prebiotic and get fermented by your good bacteria. Fermentation is a metabolic process that utilises sugar to produce alcohol, gases, or organic acids without the use of oxygen (anaerobic). These products are then used by the beneficial bacteria to produce energy, increase their numbers, and diversify.
The two prebiotic fibres with the most research behind them are oligofructose and inulin. There are several others of course, so to learn more about prebiotics and common prebiotic-rich foods click here. The best studied among the beneficial bacteria are Lactobacilli and Bifidobacteria. These beneficial bacteria use inulin and oligofructose to give them energy and multiply. They also help them repopulate the fermentation factory (your colon). What do we get from these so-called beneficial bacteria?
Together with the immune cells found in your large intestines, the beneficial bacteria form a protective barrier throughout your colon to prevent harmful bacteria from gaining access to your body. Neat, huh? As if that wasn’t enough, beneficial bacteria also produce vitamin K2 (menaquinone). Vitamin K2 a source of vitamin K which is needed by your liver to produce blood-clotting proteins to help stop bleeding such as from wounds. Another byproduct of beneficial bacteria is biotin (Vitamin B7), a water-soluble vitamin which our bodies can’t synthesise. It’s responsible for the optimal growth of your hair, skin, and nails.
Here are some more cool by-products of fermentation:
SCFA stands for short chain fatty acids. SCFAs increase blood flow to your large intestine promoting optimal nutrient absorption.
Propionate increases muscular contractions around your large intestine to propel food towards the end of your colon more effectively.
Butyrate normalises the appearance of the cells lining the surface of your colon and at the same time provides food for them.
All three of the above by-products acidify the pH in your colon making it difficult for harmful bacteria to live in, but a safe haven and workplace (factory) for beneficial bacteria.
The average daily dietary fibre requirement is between 25g to 30g. Eating plenty of fibre reduces your risk of developing cardiovascular disease, colon cancer, haemorrhoids, and constipation. But it’s sad to announce that more than 95% of Australians and almost 3 out of 4 New Zealanders don’t consume enough vegetables and fruits.
In summary, all three of these important groups of fibre have their unique health benefits. Try to include some of each kind of fibre in your diet regularly to keep your good gut bacteria healthy, keep the bad ones at bay and promote a healthy digestive system. If you’re not used to eating fibre, start with a small amount and gradually increase your servings. Eating too much too soon can lead to a bloated feeling, flatulence, and even cramps. This is particularly the case if you’re taking a fibre supplement rather than just increasing fibre-rich whole foods. Plus, don’t forget to drink more water.