However, most professionals would agree that a diet should be well balanced between the food groups, and it’s better to include more things like vegetables and fermented foods in your diet than restrict yourself unnecessarily. Eating foods that promote gut health improves your overall health too.
Why is everyone so concerned about fiber?
The importance of fiber has been known for decades. The late great surgeon and fiber researcher Denis Burkitt once said, “If you pass small stools, you have to have large hospitals.” But dietary fiber does more than just help move your bowels. Fiber can be considered a prebiotic nutrient.
Prebiotics aren’t actively digested and absorbed, rather they are selectively used to promote the growth of a beneficial species of microbes in our gut. These microbes then help digest foods for us so we can obtain more nutrients, promote gut barrier integrity, and prevent the growth of harmful bacteria.
Prebiotics aren’t actively digested and absorbed, rather they are selectively used to promote the growth of a beneficial species of microbes in our gut.
Good sources of dietary fiber include whole grains, fruits and vegetables, beans and legumes, and nuts and seeds. There is a lot of emphasis on soluble fibers and less on insoluble fibers, but in reality, most foods will contain a mixture of both, and they each have their merits.
There’s plenty of evidence supporting the benefits of dietary fiber. Fiber isn’t just associated with colon health; it’s associated with overall health and brain health through the gut-brain axis. Diets low in fiber have been associated with gastrointestinal disorders such as irritable bowel syndrome or inflammatory bowel disease.
Fiber is associated with overall health and brain health through the gut-brain axis.
There are some gastrointestinal diseases, like Celiac disease, which are not typically associated with the benefits of dietary fiber. However, there isn’t a consensus to the specific type of fiber and dose that would be beneficial in treating most diseases.
Not all fiber is good fiber
Shockingly, not all fiber is good for you. Fiber is used as an umbrella term for indigestible plant polysaccharides, so there are many different types with varying fermentability, solubility and viscosity in the gut.
To make things more complex, the source matters too. Fiber from one plant isn’t the same as fiber from another plant. Additionally, the old proverb, “too much good is not good” rings true, where overconsumption of fiber supplements can cause symptoms such as constipation, bloating and gas. This is partly due to the differences in gut microbiomes that affect the ability to metabolize fiber to produce beneficial molecules like short-chain fatty acids.
Dietary fiber is an important part of a healthy diet that can promote both gut and overall health. Fiber helps you feel more satisfied after meals and helps to regulate your blood sugar and cholesterol. Do your best to consume fiber as part of your diet, and when needed, take only the dose of supplements as recommended.
Prebiotics promote the growth of gut microbes that can affect gut health and immunity in the context of many different diseases, although not all fibers are created equal. While fiber won’t cure illness, diet is a great addition to medicines and treatment strategies that can improve their efficacy.
Written by Mark Wulczynski, Medical Sciences PhD Candidate, McMaster University.