Updated: Nov 2, 2021
Dietary fibre is found in plant-based foods and cannot be digested by the human enzymes that are produced during digestion. They reach the large intestines virtually intact where they are fermented by the gut bacteria or used to bulk our stools. The most beneficial fibre that can be used by the gut bacteria is prebiotics.
The government recommendation is that we eat about 30g per day of fibre, however the average person in the UK has an intake of about 18g. This is similar in children. Even small increments of fibre per day can make a difference to health. Here are the reasons why you need to eat more.
According to the American Gut Project people who ate 30 different plant types per week had a better diversity of gut bacteria that those who ate 10 or less. This is because prebiotics and resistant starch help to stimulate Lactobacillus and Bifidobacterium bacteria that are known to help improve overall human health. This is turn helps to crowd out bacteria such as Escherichia coli and Clostridia which may become pathogenic and cause illness or disease.
Prebiotics may also play a role in management of autoimmune diseases like Hashimoto’s whereby leaky gut is an issue. They help to improve the gut lining by modulating zonulin which is produced when the gut lining is ‘broken and inflamed’. Prebiotics also encourage the production substances that provide fuel for the gut. Supplementing with galactooligosaccharides (GOS) may help to improve leaky gut.
One factor in oestrogen dominant conditions like PMS, endometriosis, fibroids, infertility, etc, is unbalanced gut microbiota. Higher levels of some types of bacteria can produce high levels of beta-glucuronidase which detach oestrogen from the metabolite that is helping them be excreted from the body. This then allows higher levels of oestrogen to be recycled around the body to cause further disruption. Studies show that taking 15g of inulin and GOS may help hormonal conditions.
Strengthens the Immune System.
A study on mice fed a soluble fibre diet (such as, apples, pears, oats, barley, nuts, seeds, lentils, citrus fruits, strawberries, and carrots.) versus a insoluble fibre diet (such as, whole wheat, potatoes, green leafy vegetables) showed that when introduced to lipopolysaccharides (a substance that causes the body to mimic a bacterial infection) those on the soluble fibre diet where only half as sick and their recovery time was 50% quicker than those on the insoluble fibre diet. This is because soluble fibre stimulates an anti-inflammatory protein called interleukin-4 (IL-4) which helps to reduce inflammation and therefore reduces activity in the immune system. That does not mean we should avoid insoluble fibre, far from it. Insoluble fibre is needed to help form good stools that pass easily out of the body. This type of stool will help transport toxins and debris out of the digestive system which means less toxins circulating around the body and again less immune activity going on.
Healthy Cholesterol and Blood Sugar Levels
Soluble fibre is thought to bind to cholesterol and therefore assist in out of the body before it can be absorbed. This helps to reduce the activity of bad cholesterol but helps to maintain the good cholesterol.
Resistant starch found in oats, green bananas, cooked and cooled rice and potatoes, helps to regulate the release insulin and glucose after a meal. More balanced sugar levels can help to prevent the onset of diabetes type 2.
Healthy Weight Management
Balancing blood sugars is also helpful in the management of maintaining a healthy weight. Spikes in blood sugars from diets high in refined carbohydrates and sugary products including white bread, pasta, sweets, cakes and biscuits cause the excess sugar to be turned into fat and stored in the fat tissues. Also, inulin rich foods, that is onions, garlic, leeks, bananas, asparagus and chicory root may help to modulate blood sugar balance by regulating the hormones involved in regulating appetite. These hormones induce satiety and helps us to know when we are full. Overeating is one of the biggest reasons for weight gain.
Another reason is an imbalance in the gut bacteria. People who have weight issues have a greater increase in the Firmicutes and a decrease in the Bacteriodites bacteria. Ensuring you have good fibre intake will help to readdress this balance and improve the gut bacteria status.
How then do you get enough fibre in your diet?
Eat a rainbow – at least 7 fruit and vegetables of different colour. Try berries with your breakfast, add vegetable soups and salad to your lunch, ensure you have ½ a plate of vegetables with your evening meal.
Healthy plant-based snacking – vegetable sticks with hummus, nuts, seeds, fruit with oatcakes.
Swap refined carbohydrates for whole grains – white bread for oatcakes, rye bread; white rice from brown rice, white pasta for brown pasta, brown rice pasta, red lentil, buckwheat.
With digestive issues such as IBS many people are told to reduce fibre in their diet. This may be detrimental to overall health. It is best for people to start slow and build up gradually. It may help to take a digestive enzyme to help support digestion of these foods.
If you want further help in improving your digestive system and/or increasing your fibre in your diet check out my 7 Day Gut Plan. This may also be useful in reducing weight.
If you would like 1-2-1 advice check out my services page for more details.
Marie Jarvis, Nutritionist / Nutritional Therapist (BANT)