The Reason Why Fiber Is The Best Thing To Improve Gut Health

fiber gut health vegetables whole foods Jun 27, 2022


Less than 3 percent of Americans get the recommended minimum adequate intake of fiber. And if 97 percent of Americans are deficient in fiber, and 97 percent of Americans get enough protein, then shouldn’t we be focusing more of our attention on fiber?

Focusing On Fiber is More Important Than Protein

So, the question isn’t “Where do you get your protein?” but “Where do you get your fiber?” Americans only get about 15 grams a day. The minimum daily requirement is 25 to 30 grams a day from food, not supplements. And the statistics for men look even worse. Studies have found that the percentage of men between ages 14 and 50 getting the minimum adequate intake is 0 percent.

This deficit is stunning in that dietary fiber has been proven to protect against diabetes, metabolic syndrome, cardiovascular disease, obesity, and various cancers as well as high cholesterol, blood pressure, and blood sugars. Therefore, it is not surprising that fiber is listed as a nutrient of concern in the federal Dietary Guidelines---protein is not.

A National Institute of Health study found that people who consumed higher amounts of fiber, particularly from grains, had a significantly lower risk of dying from all causes over a nine-year period compared to those who consumed lower amounts of fiber.

Why Do We Eat More Fiber? 

By definition, fiber is only found in plants. There is no fiber in meat, dairy, or eggs, and little or no fiber in processed food. Therein lies the problem. Americans should be eating more beans, vegetables, fruits, whole grains, nuts, and seeds. 

Can you get the same benefits from fiber supplements? Studies associating high fiber intake with lower risk of disease and death relate only to fiber from food intake rather than from fiber isolates, extracts or supplements. Whole plant foods are of fundamental importance in our diet. 

As a result, most of the illnesses seen by medical professionals today originate from a fiber-deficient diet. Fiber's many benefits are:

  • Fiber removes toxic waste products and carcinogens in our intestinal tract, which helps protect against colon cancer.
  • Fiber promotes the growth of good bacteria in our intestinal tract, which helps us maintain a healthy immune system.
  • Fiber removes unwanted components circulating in our blood stream such as excess estrogen, testosterone and pharmaceutical drugs. Fiber attaches itself to these components, and escorts them out of the body.
  • Hormone related conditions such as menopausal hot flashes, PMS, heavy periods, and breast and prostate cancer are less common in those consuming a plant-rich diet.
  • Fiber helps eliminate excess cholesterol which lowers our low-density lipoprotein, or "bad," cholesterol levels.
  • Fiber slows the absorption of sugar and helps improve blood sugar levels which is crucial for diabetics.
  • Fiber facilitates weight loss by filling our stomachs quickly. This results in fewer calories consumed as well as producing and maintaining satiety. High-fiber diets are also lower in calories.
  • A high-fiber diet also improves gastrointestinal function, which protects against constipation, hemorrhoids, and diverticulosis.

Dr. Greger adds, "Dietary fiber has been protectively associated in population studies with the risk of diabetes, metabolic syndrome, cardiovascular disease, obesity, and various cancers as well high cholesterol, blood pressure, and blood sugars. Plant-derived diets tend to contribute significantly less fat, saturated fat, cholesterol, and food-borne pathogens, while at the same time offering more fiber, folate, vitamin C, and phytochemicals, all essential factors for disease prevention, and optimal health and well-being." 

Fiber Is Your Gut’s Favorite Food

Fiber is the true heart and soul of gut health. And fiber and gut health leads to better health in everything. From your cardiovascular system to your brain and even your hormonal health. 

All plants contain fiber, and only plants contain fiber. Not only that,  but each plant contains a unique type of fiber. Fiber, in general, is the preferred food of your gut microbiome. 

Microbes are picky eaters. They are all unique and have their specific dietary preferences. When you eat a specific plant, the unique fiber in that plant feeds a unique group of microbes. Scientists are calling this a guild. There is a guild that forms to unpack the specific fiber in your diet and they reward you by producing short chain fatty acids (SFCA)

Short Chain Fatty Acids Are The Key To A Lot Of Health Benefits

High-fiber foods, such as fruits, veggies, legumes and whole grains, encourage the production of SFCA, which play an important role for overall health and in preventing and fighting disease. They can help reduce the risk of certain inflammatory diseases including heart disease, obesity, type 2 diabetes, metabolic syndrome, and many others.

About 95 percent of the short-chain fatty acids (SCFA) that are produced when fiber is fermented in the colon are:

  • Acetate 
  • Propionate
  • Butyrate 

All three have significant anti-inflammatory properties and they work together for the good of your health. Butyrate is known specifically to help heal and fix the lining of the gut  and increase colonic motility (if you suffer from IBS then you want this). Butyrate is also known for altering gene expression to help inhibit cancer formation. All types of SCFAs have been shown to protect against congestive heart failure and high blood pressure, and protect the brain from Parkinson’s disease. And SCFAs may even help with ADHD. Children on a high fiber diet demonstrate better cognitive control than children who eat a lower fiber diet.  

Just Eat More Plants

The good bugs in your gut love plants, so eat more of them! Before you go start grabbing all the plant-based processed foods out there, note that eating actual plants is where the magic happens. The more unrefined and unprocessed your plants are, the better chance you have of consuming the fibers and carbohydrates the good bacteria actually want. Each type of fiber we consume produces a different mix of these SCFA’s. So it is important to consume a diversity of plants to get the benefits of all three different kinds of SCFA. 

How Many Plants Do I Need To Eat?

Make it your goal to eat 30 different plants a week (including fruits, vegetables, whole grains, nuts and seeds). Here are some ideas you can employ to get your plant number count up this week:

  • Choose a variety of greens including bok choy, kale and cauliflower
  • Choose high fiber fruits like apples, pears and berries
  • Always have nuts and seeds on hands: cashews, almonds, hemp hearts, etc.
  • Select 100 percent whole grains, give whole grain sourdough a try!
  • Always have 2-3 legume options in your pantry: chickpeas and lentils are versatile and can be canned or dried
  • Chickpea flour can be a great way to add more protein and fiber 

We have to take care of our gut microbes so they can do their job. And if we take care of them, they will help us by producing short-chain fatty acids that provide us so many health benefits.


Nielsen, Desree. (2022). Good For Your Gut: A plant based digestive health guide and nourishing recipes for living well. 


Tomova, A., Bukovsky, I., Rembert, E., Yonas, W., Alwarith, J., Barnard, N. D., & Kahleova, H. (2019). The Effects of Vegetarian and Vegan Diets on Gut Microbiota. Frontiers in nutrition, 6, 47.


den Besten, G., Lange, K., Havinga, R., van Dijk, T. H., Gerding, A., van Eunen, K., Müller, M., Groen, A. K., Hooiveld, G. J., Bakker, B. M., & Reijngoud, D. J. (2013). Gut-derived short-chain fatty acids are vividly assimilated into host carbohydrates and lipids. American journal of physiology. Gastrointestinal and liver physiology, 305(12), G900–G910.


University of California-San Diego. (2018). Big Data from the World’s Largest Citizen Science Microbiome Project Serves Food For Thought.

Davis C. D. (2016). The Gut Microbiome and Its Role in Obesity. Nutrition today, 51(4), 167–174.


Li, F., Hullar, M. A., Schwarz, Y., & Lampe, J. W. (2009). Human gut bacterial communities are altered by addition of cruciferous vegetables to a controlled fruit- and vegetable-free diet. The Journal of nutrition, 139(9), 1685–1691.


Díez-Sainz, E., Lorente-Cebrián, S., Aranaz, P., Riezu-Boj, J. I., Martínez, J. A., & Milagro, F. I. (2021). Potential Mechanisms Linking Food-Derived MicroRNAs, Gut Microbiota and Intestinal Barrier Functions in the Context of Nutrition and Human Health. Frontiers in nutrition, 8, 586564.

Levine, A., Sigall Boneh, R., & Wine, E. (2018). Evolving role of diet in the pathogenesis and treatment of inflammatory bowel diseases. Gut67(9), 1726–1738.

Chutkan, R., Fahey, G., Wright, W. L., & McRorie, J. (2012). Viscous versus nonviscous soluble fiber supplements: mechanisms and evidence for fiber-specific health benefits. Journal of the American Academy of Nurse Practitioners, 24(8), 476–487.


Krebs-Smith, S. M., Guenther, P. M., Subar, A. F., Kirkpatrick, S. I., & Dodd, K. W. (2010). Americans do not meet federal dietary recommendations. The Journal of nutrition, 140(10), 1832–1838.


Park, Y., Subar, A. F., Hollenbeck, A., & Schatzkin, A. (2011). Dietary fiber intake and mortality in the NIH-AARP diet and health study. Archives of internal medicine, 171(12), 1061–1068.

Wick J. Y. (2012). Diverticular disease: eat your fiber!. The Consultant pharmacist : the journal of the American Society of Consultant Pharmacists, 27(9), 613–618.


Dilzer, Allison MS, RD; Jones, Julie M. PhD, LN, CNS; Latulippe, Marie E. MS, RD The Family of Dietary Fibers, Nutrition Today: May/June 2013 - Volume 48 - Issue 3 - p 108-118

doi: 10.1097/NT.0b013e3182941d82 


Threapleton, D. E., Greenwood, D. C., Evans, C. E., Cleghorn, C. L., Nykjaer, C., Woodhead, C., Cade, J. E., Gale, C. P., & Burley, V. J. (2013). Dietary fibre intake and risk of cardiovascular disease: systematic review and meta-analysis. BMJ (Clinical research ed.), 347, f6879.


Satija, A., & Hu, F. B. (2012). Cardiovascular benefits of dietary fiber. Current atherosclerosis reports, 14(6), 505–514.


Li, S., Flint, A., Pai, J. K., Forman, J. P., Hu, F. B., Willett, W. C., Rexrode, K. M., Mukamal, K. J., & Rimm, E. B. (2014). Dietary fiber intake and mortality among survivors of myocardial infarction: prospective cohort study. BMJ (Clinical research ed.), 348, g2659.

Greger, MIchael. (2019). Do Vegetarians Get Enough Protein? Accessed: June 29, 2022.

Click here to learn more about our plant-based membership, courses and coaching programs.

Learn More

Stay connected with news and updates!

Join our mailing list to receive the latest plant-based tips, tricks, and recipes.
Don't worry, your information will not be shared.

We hate SPAM. We will never sell your information, for any reason.