Fiber is a type of carbohydrate that is found in plant-based foods like grains, fruits, vegetables, nuts, and beans. Adequate fiber intake may improve digestion and reduce your risk of developing various conditions, including heart disease,
diabetes, diverticular disease, and constipation. According to the World Health Organisation recommendation, an adult should consume about 30g of fiber per day. That’s about eating 400g (or 5 servings) of fruit and vegetables per day.
Dietary fiber can’t be completely broken by the human digestive system and mostly passes through your
digestive system without being digested. That’s why it is also sometimes called roughage and is considered best to improve the frequency of bowel movements. However, fiber is also a vital source of sustenance for beneficial bacteria in your gut. Here we explain the role of fiber in improving your digestive health.
How fiber benefits your digestive health
There are two types of fiber: soluble and insoluble fiber. Soluble fiber dissolves easily dissolves in water and is broken down into a gel-like substance in the colon. Insoluble fiber is the type that is often called “roughage.” As insoluble fiber doesn’t dissolve in water, it isn’t broken down by the gut and absorbed into the bloodstream.
Soluble fibers are considered to have prebiotic properties as they are fermented (broken down) by beneficial bacteria in the gut to produce essential short-chain fatty acids like butyrate, acetate, and propionate. Prebiotics feed the friendly gut bacteria, which in turn produce nutrients for your colon cells and keep your digestive system healthy.
In addition, soluble fiber helps soften stools and support regular bowel movements by drawing water into your gut. It also slows the absorption of macronutrients from food, especially sugars, and thus helps stabilise blood glucose levels. This is the reason why soluble fiber is said to be beneficial for people with
insulin resistance, metabolic syndrome, prediabetes, and type 2 diabetes.
Studies have shown that soluble fiber can increase satiety (feeling of fullness) and delay hunger for longer. This helps in
weight loss and fight obesity.
Foods that contain soluble fiber include fruits, oats, legumes and barley.
Because insoluble fiber is resistant to the activity of human digestive enzymes, it passes through the gastrointestinal tract unbroken and the gut microbiota has little effect on it. Instead, it provokes the gut lining to release mucus and water. Insoluble fiber absorbs the water, which adds bulk to the stool and makes it softer. The additional mucus also allows the stool to easily transit through the body and exit with less strain. Thus adding insoluble fiber to your diet can help ease
constipation. What’s more, insoluble fiber, like soluble, also supports insulin sensitivity, which may help reduce your risk for diabetes.
Examples of foods that contain insoluble fiber include wheat, seeds, corn bran, leafy vegetables, broccoli, and tomatoes.
Caution: And although most people don’t eat enough fiber, consuming too much fiber may lead to problems like bloating, gas, abdominal pain, constipation, diarrhea or loose stools. Eating more than 70 grams (g) of fiber a day may give you these uncomfortable side effects.