The Healthy Benefits of Fiber

Fiber doesn’t get the credit it deserves. For too long, the good name of dietary fiber has been relegated to only being mentioned by the prune-eating elderly in 90’s television shows, fiber supplement ads coyly avoiding the mention of constipation, and health recommendations telling us to eat more oatmeal and celery. Our culture doesn’t widely acknowledge what an important role fiber plays in a healthy lifestyle. In the US, less than 5% of adults get the recommended amounts of dietary fiber, and, on average, both adults and children consume under 50% of the recommended daily serving. As the suggested daily serving of fiber for adults is 25 to 30 grams of fiber per day, that means people are only taking in about 15 grams daily. Maybe we ignore it, blushing too easily and avoiding talking about our bowels and their subsequent movements. One thing is certain, Americans are consuming far too little dietary fiber and easily could get more from healthy snacks.


Other than its obvious connection to easier and more regular bowel movements, high-fiber diets have been shown, in many studies over decades, to lower incidences of coronary heart disease, stroke, peripheral vascular disease, obesity, and diabetes. It has been shown to significantly lower cholesterol, blood pressure, and inflammation of the bowels. Surely, if it simply had better PR, and people knew how easy it was to eat enough fiber, it would be hailed as the virtuous nutrient that it is.


While a healthy balance of macronutrients–the carbohydrates, fats, and proteins that our body absorbs while digesting food–is essential for our bodies, it would be a mistake to say that we are only made of human cells and that we need only to feed those cells. Our bodies are made up of trillions of cells, only about half of which are human. The other half consists of hundreds of species of symbiotic microbes, taking up residence on and, most importantly, inside our bodies, providing a whole host of services that the human body is reliant on. Intestines can better be thought of as a forest–a delicately balanced mixture of organisms interacting with one another–rather than isolated organs. The intestinal tract provides the environmental base on which gut flora can thrive. Our diet feeds them, and they provide us with digestive and health services in return.


It may be best, at this point, to provide a definition, so that you might understand the functions and benefits of fiber. Dietary fiber is any plant matter that the human body can’t digest and absorb. It generally passes through the majority of the digestive system before reaching the intestines, where it finds its true functions in the human body. Fiber, broadly, comes in two varieties: soluble and insoluble. Insoluble fiber is usually associated with the term dietary fiber. It’s the “roughage” side of the fiber family that does the yeoman’s work of helping form stools and cleaning the gut as it moves through. Insoluble fiber does the work of “bulking” stool with less dense material, reducing the effort of moving it through the colon. It can also stimulate the intestines to produce more water, making stools easier to pass. An increase in dietary fiber has been shown to reduce constipation in the vast majority of those who suffer from chronic constipation. Also, as a side hustle, I guess, insoluble fiber is associated with reduced diabetes risks, increasing insulin sensitivity, and reducing incidence of blood sugar spikes after meals high in fiber.


Soluble fiber, the maybe less popularly known side of fiber, is the plant matter that is absorbed and digested by the gut biome and helps regulate water levels in the intestines as food passes through. It feeds the microbes that help feed us.
A smaller group within the soluble fiber is the family of mysterious prebiotics, a seemingly arcane cabal whose powers are only truly understood by trendy health food companies in order to confuse and draw customers into buying more expensive foods. Well, it turns out to be much simpler and less menacing than any marketing conspiracy. Probiotic foods are those that implant fully formed beneficial microbes into the digestive tract. This can help jumpstart and maintain a healthy balance of microbes in turbulent times, such as after a schedule of antibiotics. Prebiotics, however, are just the various nutrients on which gut flora feed and harness energy. 


It may seem even more mysterious why prebiotics are referred to as feeding the “good” bacteria and warding off the “bad” bacteria that proliferate in the presence of an unvaried diet low in dietary fiber. But a better way of thinking about this is that the human intestine is exactly as we refer to it, a biome.  Just like in a forest, not every species feeds on the same nutrients, so if there is only a narrow spectrum of nutrients, only a small number of the possible species will prosper. With a smaller number of possible species, there is more space for the harmful species of bacteria to take over and go unchecked by other bacteria and our immune system.
 
Inversely, if the intestines have a diet high in diverse types of fiber, a wide spectrum of species can flourish and create a better balance in the ecosystem. If there is a higher number of species filling in the possible space, then it is less likely that one species can proliferate to an extent that would be harmful to one’s health. The immune system is better able to eradicate a small number of harmful bacteria without prompting a larger-scale immune response, which causes inflammation. So, consuming a wide variety of prebiotics isn’t necessarily about feeding only the good bacteria, but about creating as diverse an enteric ecosystem as possible.


The fun doesn’t stop there with soluble dietary fiber, though. It also interacts with the body in ways that have cumulative, long-lasting effects on digestion. Gut flora digest and ferment certain dietary fibers, which produce short chain fatty acids (SCFAs). SCFAs are the main food source for colonocytes, the cells that make up the lining of the colon. By feeding the colonocytes, they can have better immune responses and create a better environment for the gut flora, which create more SCFAs, which create a better environment for the gut flora, and so on. They also start a set of processes that produces more mucus, which, just like the mucus in the nose, protects the intestinal lining (and therefore the body) from harmful microbes. 

One last incredible benefit of prebiotics is that they have been shown to significantly reduce cholesterol levels. That fact doesn’t link to the others as easily, but it isn’t worth leaving out. My family retains cholesterol rather well, so this fact seemed particularly pertinent. No one has ever explained this to me plainly. I suspect, as a whole, people are fairly uninformed as to what the entirety of what dietary fiber is and can do. It seems to always be mentioned in passing in health class and mentioned as a thing that can be supplemented in a diet. When truly it should be a central part of how diet is taught and thought about. The process of researching and writing this post has converted me to a true fiber evangelist. I have been preaching the good word of the scientifically proven, peer-reviewed, potentially life changing benefits of fiber and its beautiful nuances.
So how does one achieve this internal idyll inside your intestines? How is the layperson supposed to go about nourishing trillions of symbiotes with a wide variety of nutrients? How does one try to maintain those health benefits indefinitely? Must I eat undressed salads and drink fiber supplements in order to stave off the approaching void?


To answer some of these questions and hopefully elevate some fears, I will provide a slightly protracted, but simple set of answers. Firstly, fiber supplements can be helpful in some cases, but only do so much. They usually only consist of one or a few types of dietary fiber that are good at alleviating constipation immediately, but as we discussed earlier, a wide variety of fiber sources will maintain a wide variety of gut flora, which are much better at working with your body to regulate the intestine than a single fiber supplement can give. Trying to replace millions of years of evolution and symbiosis with a supplement company’s over the counter fiber solution is a fool’s errand. 

The greatest thing one can do in the quest for a good amount of dietary fiber is to eat a lot of different stuff. Eat new things, revisit staples. Go out and find a great many sources of fiber, because a varied diet will help cultivate a diverse gut biome.

  • Some good food-based sources of insoluble fiber are fruits, vegetables (preferably with the skins), whole grains, and nuts. 
  • Soluble fiber sources include oats, beans, flax seeds, and root vegetables. 

Don’t ever feel as though eating healthier means you have to eat tasteless food. You’re on a snack website, so you obviously care about delicious food. We made the snack website, so we care about providing flavor. We’re in this together. There are lots of ways to get dietary fiber. A very helpful, and tasty way is through snacking. It is a way of getting a wide variety of different foods, with varying fiber content, at a low caloric and monetary cost. All the while enjoying tasty and healthy snacks! 

Healthy Snacks with Fiber:

Honestly, I feel like fiber should really get a much larger push from society than it gets. Eat more fiber. Cultivate your inner sanctuary for righteous, free thinking, diverse bacteria. It’s so much easier and more delicious than people make it out to be. Treat yourself and make yourself happier and healthier!

 

Sources

  • Abbott, Allison. “Scientists Bust Myth That Our Bodies Have More Bacteria than Human Cells.” Nature News, Nature Publishing Group, 8 Jan. 2016, www.nature.com/news/scientists-bust-myth-that-our-bodies-have-more-bacteria-than-human-cells-1.19136.
  • Anderson, James W, et al. “Health Benefits of Dietary Fiber.” Nutrition Reviews, vol. 67, no. 4, Apr. 2009, pp. 188–205., doi:10.1111/j.1753-4887.2009.00189.x.
  • Buddington, Randal, et al. “Oligofructose Provides Laxation for Irregularity Associated with Low Fiber Intake.” Nutrients, vol. 9, no. 12, 2017, p. 1372., doi:10.3390/nu9121372.
  • Claesson, Marcus J., et al. “Gut Microbiota Composition Correlates with Diet and Health in the Elderly.” Nature, vol. 488, no. 7410, 13 July 2012, pp. 178–184., doi:10.1038/nature11319.
  • Food and Drug Administration Department of Health And Human Services. Code of Federal Regulations, Title 21, Chapter 1, Subchapter B, Part 101, Subpart D - Specific Requirements for Nutrient Content Claims, Section d . Vol. 2, 2019.
  • Forgie, Andrew J., et al. “Diet-Microbe-Host Interactions That Affect Gut Mucosal Integrity and Infection Resistance.” Frontiers in Immunology, vol. 10, 2019, doi:10.3389/fimmu.2019.01802.
  • Forgie, Andrew J., et al. “Diet-Microbe-Host Interactions That Affect Gut Mucosal Integrity and Infection Resistance.” Frontiers in Immunology, vol. 10, 2019, doi:10.3389/fimmu.2019.01802.
  • Furrie, E. “Synbiotic Therapy (Bifidobacterium Longum/Synergy 1) Initiates Resolution of Inflammation in Patients with Active Ulcerative Colitis: a Randomised Controlled Pilot Trial.” Gut, vol. 54, no. 2, 1 Feb. 2005, pp. 242–249., doi:10.1136/gut.2004.044834.
  • Hansson, Gunnar C. “Role of Mucus Layers in Gut Infection and Inflammation.” Current Opinion in Microbiology, vol. 15, no. 1, 19 July 2013, pp. 57–62., doi:10.1016/j.mib.2011.11.002.
  • Ho, Kok-Sun. “Stopping or Reducing Dietary Fiber Intake Reduces Constipation and Its Associated Symptoms.” World Journal of Gastroenterology, vol. 18, no. 33, 2012, p. 4593., doi:10.3748/wjg.v18.i33.4593.
  • Ho, Kok-Sun. “Stopping or Reducing Dietary Fiber Intake Reduces Constipation and Its Associated Symptoms.” World Journal of Gastroenterology, vol. 18, no. 33, 7 Sept. 2012, p. 4593., doi:10.3748/wjg.v18.i33.4593.
  • Human Microbiome Project Consortium. “Structure, Function and Diversity of the Healthy Human Microbiome.” Nature, vol. 486, no. 7402, 13 June 2012, pp. 207–214., doi:10.1038/nature11234.
  • Klinder, Annett, et al. “Impact of Increasing Fruit and Vegetables and Flavonoid Intake on the Human Gut Microbiota.” Food & Function, vol. 7, no. 4, 7 Apr. 2016, pp. 1788–1796., doi:10.1039/c5fo01096a.
  • Lambeau, Kellen V., and Johnson W. Mcrorie. “Fiber Supplements and Clinically Proven Health Benefits.” Journal of the American Association of Nurse Practitioners, vol. 29, no. 4, Apr. 2017, pp. 216–223., doi:10.1002/2327-6924.12447.
  • Macfarlane, S., et al. “Review Article: Prebiotics in the Gastrointestinal Tract.” Alimentary Pharmacology and Therapeutics, vol. 24, no. 5, 16 Aug. 2006, pp. 701–714., doi:10.1111/j.1365-2036.2006.03042.x.
  • Mcrorie, Johnson W., and Nicola M. Mckeown. “Understanding the Physics of Functional Fibers in the Gastrointestinal Tract: An Evidence-Based Approach to Resolving Enduring Misconceptions about Insoluble and Soluble Fiber.” Journal of the Academy of Nutrition and Dietetics, vol. 117, no. 2, 15 Nov. 2017, pp. 251–264., doi:10.1016/j.jand.2016.09.021.
  • Parnell, Jill A., and Raylene A. Reimer. “Prebiotic Fiber Modulation of the Gut Microbiota Improves Risk Factors for Obesity and the Metabolic Syndrome.” Gut Microbes, vol. 3, no. 1, 2012, pp. 29–34., doi:10.4161/gmic.19246.
  • Ramos, Silvia C, et al. “The Role of Soluble Fiber Intake in Patients under Highly Effective Lipid-Lowering Therapy.” Nutrition Journal, vol. 10, no. 1, 2 Aug. 2011, doi:10.1186/1475-2891-10-80.
  • Sabatino, A. Di, et al. “Oral Butyrate for Mildly to Moderately Active Crohns Disease.” Alimentary Pharmacology and Therapeutics, vol. 22, no. 9, 1 Nov. 2005, pp. 789–794., doi:10.1111/j.1365-2036.2005.02639.x.
  • Salas-Salvadó, Jordi, et al. “Effect of Two Doses of a Mixture of Soluble Fibres on Body Weight and Metabolic Variables in Overweight or Obese Patients: a Randomised Trial.” British Journal of Nutrition, vol. 99, no. 6, 22 Nov. 2007, pp. 1380–1387., doi:10.1017/s0007114507868528.
  • Scarpellini, E., et al. “Efficacy of Butyrate in the Treatment of Diarrhoea-Predominant Irritable Bowel Syndrome.” Digestive and Liver Disease Supplements, vol. 1, no. 1, Sept. 2007, pp. 19–22., doi:10.1016/s1594-5804(08)60006-6.
  • Slavin, Joanne L. “Position of the American Dietetic Association: Health Implications of Dietary Fiber.” Journal of the American Dietetic Association, vol. 108, no. 10, 2008, pp. 1716–1731., doi:10.1016/j.jada.2008.08.007.
  • Weickert, Martin O., and Andreas F. H. Pfeiffer. “Metabolic Effects of Dietary Fiber Consumption and Prevention of Diabetes.” The Journal of Nutrition, vol. 138, no. 3, Mar. 2008, pp. 439–442., doi:10.1093/jn/138.3.439.
  • Wong, Julia M. W., et al. “Colonic Health: Fermentation and Short Chain Fatty Acids.” Journal of Clinical Gastroenterology, vol. 40, no. 3, Mar. 2006, pp. 235–243., doi:10.1097/00004836-200603000-00015.
  • Yang, Jing. “Effect of Dietary Fiber on Constipation: A Meta Analysis.” World Journal of Gastroenterology, vol. 18, no. 48, 28 Dec. 2012, p. 7378., doi:10.3748/wjg.v18.i48.7378.
  • Yao, Yibo, et al. “Dietary Fibre for the Prevention of Recurrent Colorectal Adenomas and Carcinomas.” Cochrane Database of Systematic Reviews, 2017, doi:10.1002/14651858.cd003430.pub2.

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