Fiber—Are You Getting Enough?

Dietary Fiber—Your Gut’s Best Buddy

Fiber is a type of carbohydrate that’s present in plant foods. What makes it different from other carbohydrates is that it can’t be digested or absorbed by your small intestine. Instead, it travels to the large intestine where it is partially or fully fermented and converted to short-chain fatty acids (SCFA) that play a crucial role in maintaining intestinal health.³  But their benefits don’t stop there. Studies suggest that SCFAs can also act to keep inflammation in check, regulate the immune system, promote better metabolic health, and even help to protect the brain, heart, and liver.⁴ Once all this activity occurs, whatever is left of the fiber you ate is then shuttled out of your body via your stool.

There are two types of fiber in foods, soluble and insoluble, and each one has its own health benefits. Soluble fiber is the type of fiber that dissolves in water and forms a gel-like consistency. This type of dietary fiber has been linked to a lower risk of heart disease, decreased cholesterol levels, and better blood sugar control.

Insoluble fiber, on the other hand, doesn’t dissolve in water. Instead, it aids in elimination and helps to prevent constipation. As insoluble fiber moves through the digestive tract it brushes the cells of the intestinal lining and helps to “clean” the digestive tract by picking up problematic substances and whisking them out of your system.⁵  Because of this, insoluble fiber is an essential part of detoxification.

How Much Fiber Do I Need?

The recommended amount to consume per day is 25-40 grams of a combination of soluble and insoluble fiber. More specifically, women should strive to get at least 25 grams and men should shoot for at least 38 grams per day.⁶ Yet the typical American only eats 10 to 15 grams each day. Making sure you’re getting at least the bare minimum dose of dietary fiber can have a huge impact on your overall health and longevity.

Case in point: A 2019 review of nearly 250 studies found that building your diet around lots of fiber-rich fruits, vegetables, and whole grains can reduce the risk of dying from cardiovascular disease, stroke, or type 2 diabetes by as much as 24 percent. What’s more, for every additional 8 grams of dietary fiber consumed, the risk of these diseases fell by another 5-27 percent.⁷ Another study conducted by the National Cancer Institute reported that high-fiber diets were linked to a 23 percent lower risk of death of any cause.⁸

What Are the Best Sources of Dietary Fiber?

So where are you going to get all that fiber? Good sources of soluble fiber include beans, vegetables (especially broccoli, Brussels sprouts, and sweet potatoes), fruits (particularly avocados), nuts and seeds, and whole grains. What about insoluble fiber? The good news is that the same foods that are high in soluble fiber are also great sources of insoluble fiber!

Easy Ways to Eat More Fiber

Fitting more fiber into your daily meal plan may seem a bit intimidating but it’s actually easier than you think. Here are six easy ways to up your fiber game.

Check the “Nutrition Facts” label. Choose items that contain a minimum of 3 grams of fiber per serving.  

Include at least one fruit or vegetable in every meal. Try adding some berries at breakfast, an avocado at lunch, and a cup or two of greens for dinner.

Add a veggie-packed salad to your evening meal. Beets, carrots, cucumbers, grains, nuts, and tomatoes all enhance a bowl full of greens. Let your imagination run wild when customizing your salads.

Adopt “Meatless Mondays.” Periodically creating tasty meals that revolve around beans and legumes, vegetables, or whole grains instead of meat can significantly increase your fiber intake.

Snack on fruit and popcorn. Both fruit and popcorn are excellent sources of soluble and insoluble fiber.

Try chia or flax seeds. Sprinkle on cereals and salads or include in your favorite smoothie or pudding.

Your Microbiome Needs Fiber Too

While dietary fiber provides a ton of health benefits you can feel, there’s another type of fiber that can support all those invisible microbes that live in your gut. Prebiotics are a group of special fibers that feed the beneficial bacteria (also known as probiotics) that make up your microbiome. And that’s important because these microbes play a critical role in a variety of body functions, including your digestion, immune function, metabolism, and brain.⁹

Prebiotics by themselves can provide health benefits too by producing SCFAs.¹⁰ And that can help to fortify the gut barrier and improve the symptoms of some digestive conditions. This was shown in a trial of people suffering with irritable bowel syndrome. Those taking a prebiotic supplement experienced a significant improvement in their symptoms, including bloating, gas, and bowel regularity.¹¹

While certain foods like almonds, bananas, and oats are rich in prebiotic fiber, it’s often easier to take supplemental prebiotics to ensure your gut bacteria is getting a steady supply. And it’s even better if your prebiotic fiber is packaged with several strains of probiotics to not only feed your garden of friendly flora but to repopulate the goods bugs already found there. Known as synbiotics, these two-for-one supplements provide a complete solution for supporting a healthy gut that, in turn, supports you.

While there are a number of prebiotic fibers used in synbiotics, one of the most beneficial is alpha-gluco-oligosaccharide. Studies show that this particular prebiotic not only supports the growth of beneficial gut bacteria, the production of SCFA, and overall digestive health, it also improves immune and metabolic health.^12,13 Check the label when shopping for a synbiotic supplement to make sure it contains alpha-gluco-oligosaccharide. And since alpha-gluco-oligosaccharide specifically fosters the growth of both beneficial Lactobcillus and Bifidobacterium probiotics, it’s also smart to choose a synbiotic with an array of these probiotic strains such as L.gassari, L. longum, L. rhamnous, B. bifidum, B. breve, B. infantis, B. lactis, and B. longum.

Ramping up your fiber intake can make a huge difference in the health and wellbeing of both you and your gut. Just be sure to increase your fiber intake slowly, gradually increasing the amount you eat over the course of a week or two. And add in a comprehensive synbiotic to be sure your microbiome is well-fed, too!

1. Fuller S. New horizons for the study of dietary fiber and health: A review. Plant Foods for Human Nutrition. 2016;71(1):1-12.
2. Clark MJ. The effect of fiber on satiety and food intake: a systematic review. Journal of the American College of Nutrition. 2013;32(3):200-11.
3. Guo K. Intestinal microbiota-mediated dietary fiber bioavailability. Frontiers in Nutrition. 2022;9:1003571.
4. Xiong RG. Health benefits and side effects of short-chain fatty acids. Foods. 2022;11(18):2863.
5. Health benefits of dietary fibers vary. National Institutes of Health. 2022. https://www.nih.gov/news-events/nih-research-matters/health-benefits-dietary-fibers-vary
6. Larson H. Easy ways to boost fiber in your daily diet. 2021. http://www.eatright.org/health/essential-nutrients/carbohydrates/easy-ways-to-boost-fiber-in-your-daily-diet
7. Reynolds A. Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. Lancet. 2019;393(10170):434-445.
8. Park Y. Dietary fiber intake and mortality in the NIH-AARP diet and health study. Archives of Internal Medicine. 2011;171(12):1061-8.
9. Valdes AM. Role of the gut microbiota in nutrition and health. BMJ. 2018;361:k2179.
10. Carlson JL. Health effects and sources of prebiotic dietary fiber. Current Developments in Nutrition. 2018;2(3):nzy005.
11. Silk DB. Clinical trial: the effects of a trans-galactooligosaccharide prebiotic on faecal microbiota and symptoms in irritable bowel syndrome. Alimentary Pharmacology and Therapeutics. 2009;29(5):508-18.
12. An R. Effects of oligosaccharides on the markers of glycemic control: a systematic review and meta-analysis of randomized controlled trials. Food & 2022;13(17):8766-8782.
13. Gut microbiota and immunity. NutraIngredients Europe. 2020. http://www.nutraingredients.com/News/Promotional-Features/Gut-microbiota-and-immunity

This article is for informational purposes only. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment and should never be relied upon for specific medical advice.