What is the Best Fiber Supplement?

Fiber is an important part of a healthy diet but like anything we consume, too much or too little may be problematic.  Fiber has been touted as an extremely important nutrient but is it really as beneficial as it is purported to be? When used at the right time in the right individual, fiber can be a game changer for healing the gut and improving overall health.  Let’s discuss the health benefits of fiber and the best fiber supplements if supplementation is necessary.


What is Fiber?

Fiber is a compound found in food categorized as soluble and insoluble as well as fermentability.  Fermentability is how well your gut bacteria can eat the fiber. Soluble fiber dissolves well in water and insoluble fiber does not.  This means insoluble fiber is much harder for your gut bacteria to eat and to ferment than soluble fiber so we usually start with soluble fiber supplements.  

Soluble fiber has higher fermentability than insoluble fiber so it feeds your gut bugs much better but this can lead to more gas and bloating.  Insoluble fiber has a greater chance of irritating your intestines so we usually don’t start with this type of fiber. However, insoluble fiber has low fermentability so it usually causes less bloating and gas than soluble fiber.  Most studies show that soluble fiber works better than insoluble fiber for most conditions.

What Conditions can Fiber Help Treat or Prevent?

Fiber research is difficult to properly perform because there are many variables in each person’s life that can affect their disease risk.  And since everyone has a different gut microbiota we have to take some findings with a grain of salt. Many factors have to be taken into account when studying fiber and disease such as:

  • Exercise
  • Stress levels
  • Sleep
  • Other dietary factors such as sugar intake, alcohol, processed foods etc.
  • Fruit and vegetable intake
  • Medications
  • Smoker?
  • Genetics
  • Antibiotic history


Here are some quick facts based on the latest research on fiber and various conditions:

  • Fiber reduces the risk of type 2 diabetes with fiber from fruits and vegetables being more protective than cereal fibers.  Cereal fibers work well just not as well as fruits and vegetables. Fiber supplements lower fasting glucose and hemoglobin A1c.
  • Paleo diets and low-carb diets work better than low-fat/high fiber diets for heart health and weight loss.  Interestingly, Paleo and low-carb diets are low in fiber indicating that balancing blood sugar and reducing inflammation are more important than eating a lot of fiber.
  • Fiber supplements decrease blood pressure and cholesterol but it doesn’t mean this reduces the risk of cardiovascular disease.
  • Fiber supplements help with weight loss.
  • Some research shows fiber protects against colorectal cancer and some research shows fiber has no protective effect from colorectal cancer.
  • Fiber reduces the risk of Inflammatory Bowel Diseases (IBD) like Chron’s disease and Ulcerative colitis but once you have IBD it is best to eat a low fiber diet until you are in remission and then slowly increase to a tolerable amount.
  • Fiber may make Irritable Bowel Syndrome (IBS) worse or it may help.  If you have diarrhea dominant IBS then avoiding fiber is probably a good idea as it can make some people worse.  However, if you have constipation dominant IBS, fiber may help. Like with IBD, it’s best to start with low fiber intake and slowly increase to a tolerable dose.  If your IBS is due to Small Intestinal Bacterial Overgrowth (SIBO), it is best to avoid fiber supplements until the SIBO is under control.  Fiber supplements do not appear to help much with bloating and pain in IBS but they do help with quality of life, stool consistency, and frequency.  Soluble fiber appears to work better than insoluble fiber.

When should you use a fiber supplement?

If you currently have a digestive issue such as SIBO, IBS, IBD, GERD or any of the common symptoms of gut dysfunction such as gas, bloating, cramping, indigestion, diarrhea, or constipation then you should avoid fiber supplements.  

Fiber supplements should be used when your gut is in relatively good health or after you have followed a gut healing program and you’re ready to improve your gut microbiota.  Gut healing programs include dietary changes, probiotics, digestive enzymes, gut healing nutrients, and herbal antibiotics to get the gut back in balance.  

Once your gut symptoms are gone or minimal and you have reintroduced foods that are higher in fiber such as foods that contain FODMAPs without any issues, then it may be time to try a fiber supplement.

What are the best fiber supplements?

Flaxseed Fiber

Moss Nutrition Flaxseed Fiber is made from certified organic, cold-milled whole flaxseeds, a natural source of dietary fiber and other nutrients.  This product is intended for use primarily as a fiber supplement but Flaxseed Fiber also contains dietary protein, dietary lignans and the important omega-3 essential fatty acid alpha-linolenic acid (ALA).  ALA has been researched to help support healthy cardiovascular function, healthy cell membrane structure and a healthy inflammation response.

Flaxseed and the flax plant in general are ancient botanical allies of human beings, cultivated for thousands of years for use in human dietary, livestock and industrial applications.  Flax has provided food, medicine, clothing, paper and more, leading to its Latin name Linum usitatissimum (“highly useful”). Flaxseeds, also known as linseeds, have been recognized for helping to promote healthy bowel elimination since at least 500 BC, at which time Hippocrates made note of their laxative properties. Modern research suggests that flaxseed and the oil it contains also may help to support healthy cardiovascular function and immune system health.

Flaxeed contains three primary functional food compounds: mono- and polyunsaturated fatty acids, soluble and insoluble dietary fiber, and lignans.  Lignans both provide antioxidant activity and exhibit phytoestrogenic effects. Flaxseed is the richest known source of dietary plant lignans, offering 800 times the lignan content of any other plant food.  Flaxseeds also contains vitamin E (mainly in the gamma tocopherol form), B-vitamins such as niacin and folate, and numerous minerals including significant amounts of phosphorus, potassium, magnesium and calcium.

The soluble fiber in flaxseed is rich in mucilaginous compounds that have been shown in both human and animal research to help relieve constipation.  A 2007 study found that daily consumption of ground flaxseeds with yogurt and prunes helped decrease the severity of constipation in seniors with mild constipation.  Soluble flaxseed fiber also has been associated with helping to support healthy serum cholesterol and blood lipid levels within the normal range.  

A 2012 double-blind, randomized study found subjects who consumed a drink containing flaxseed fiber for seven days exhibited decreased fasting LDL and total cholesterol and increased fat and energy excretion.  

Flaxseed fiber drinks also have been shown to help suppress appetite, increase satiety and reduce caloric consumption.  In addition to fiber, a number of bioactive compounds in flaxseeds (e.g. peptides, glycosides, ALA and lignans) have been researched to offer benefits to cardiovascular health in different ways including free radical protection and inflammation support.

The oily, nutritious and fiber-rich core of every tiny flaxseed is surrounded by a shiny, hard husk that is difficult to fully break down by chewing alone.  Pre-soaking, grinding or milling of whole flaxseeds is widely practiced to release their full nutritional and therapeutic potential. Studies suggest that milled flaxseed, such as Moss Nutrition Flaxseed Fiber provides, is remarkably resistant to oxidative degradation.  To further promote and preserve freshness, Moss Nutrition Flax Fiber is cold-milled at low temperatures, and some of the oil in the meal is removed after milling to help optimize product stability. Refrigeration after opening also is recommended to help support and extend shelf life.

How should you take Flaxseed Fiber?

Flaxseed Fiber may be combined with any liquid—from plain water or apple juice to smoothies and protein shakes.  Alternatively, the product may be consumed in a variety of creative ways, both for convenience and to increase the nutritional value of many foods.  Some examples include:

  • Sprinkle Flaxseed Fiber on top of yogurt, breakfast cereal, grain dishes or salads.
  • Mix Flaxseed Fiber into condiments such as mayonnaise and mustard.
  • Add Flaxseed Fiber to batters and baked dishes such as breads, muffins, pancakes and casseroles.

Moss Nutrition premium Flaxseed Fiber is made with organically grown, non-GMO cold-milled flaxseed.  This superior quality raw material is certified kosher by the Kosher Certification Service and certified organic by Quality Assurance International to meet USDA National Organic Program standards.  Upon packaging, the finished product is verified gluten-free by independent laboratory testing.

Start with 1 scoop a day for three days and then increase to 2 scoops a day for three days.  Then 3 scoops a day for three days and then max out at 4 scoops a day. This can be done in two doses or by taking all the scoops at one time.  Flax fiber can be taken with or without food.

If you notice gas, bloating, cramping, increased constipation, or any other gut symptoms getting worse,  reduce the dose to the maximum tolerable dose. If you don’t do well with just 1 scoop a day then it is time to try a different fiber supplement such as Acacia Fiber.

Can’t I just take ground flax seeds?

Although you will get some health benefits from grinding your own seeds, I don’t recommend doing this if you are specifically trying to heal your gut.  The most important thing is to only take the flax fiber and figure out the right dose for you. This will be more targeted in improving your gut microbiota and healing your gut.


Acacia Fiber

Moss Nutrition Acacia Fiber is a natural soluble fiber produced from the dried sap of the acacia tree. Best known for its reported role in helping to soothe irritable bowel complaints and for use as a prebiotic agent, acacia fiber is also thought to provide many of the researched benefits associated with soluble fiber in general, such as helping to maintain blood lipid values within the normal range, and helping to support healthy blood glucose control.

Acacia Fiber is sourced from various species of the acacia tree (primarily A. Senegal and A. Seyal) which are native to Sudan and other tropical/subtropical regions of the African continent, as well as neighboring countries.  Acacia fiber production has been practiced in the same manner for centuries. First, small cuts are made in the trunk, stems and branches of the tree. In response, a glue-like resinous sap seeps out of the bark and hardens into gummy blobs. This gum is hand-collected, dried and powdered to produce acacia fiber.

Also known as acacia gum or gum arabic, acacia fiber contains four primary polysaccharides (galactose, rhamnose, glucoronic acid and arabinose residues) along with the alkaline minerals calcium, potassium and magnesium.  The highly branched structure of this complex polysaccharide makes it resistant to digestion in the upper GI tract by both low-pH gastric hydrolysis and digestive enzyme degradation. These digestive resistant properties allow acacia fiber to arrive in the colon nearly intact, where it can be broken down via bacterial fermentation to produce short chain fatty acids (SCFAs) such as propionic and butyric acid. 

SCFAs provide fuel for colonic epithelial cells, help to support gut lining integrity and fortify intestinal barrier function.  Because SCFAs like butyrate are well known to help modulate inflammatory processes, acacia fiber is considered a first line prebiotic agent with anti-inflammatory activity.

In vitro studies show that acacia fiber helps support the growth of bifidobacteria and lactobacilli while decreasing levels of Clostridium species.  In vivo, as little as 10 grams of acacia fiber per day was shown to produce a significant drop in levels of the inflammatory marker C-Reactive Protein in a study of patients with kidney problems.  

In other research, 30 grams of acacia fiber taken daily for 12 weeks was associated with significant decreases in serum TNF-alpha and ESR in patients with joint problems. Reductions in joint tenderness and swelling also were reported in this study.

Although acacia fiber has been researched to benefit a range of conditions, its primary use in clinical practice is providing support for digestive comfort and function.  Acacia Fiber dissolves easily in water to form a thick, gel-like liquid with numerous functional properties. First, it slows down the rate of gastric emptying, helping to calm the gut and promote satiety.  The slippery gel can soothe inflamed GI tissues, firm the stool, support peristalsis and improve bowel functionality. Finally, by serving as a substrate for microbial fermentation, acacia fiber can help beneficially modulate the gut microbiome and promote healthy gut-associated immune function.

An 8-week clinical trial of 130 patients with irritable bowel complaints studied the effect of consuming a “composite yogurt” containing active probiotic cultures, two times per day.  Half the patients had acacia fiber added to their yogurt while the other half (control group) did not. At the end of the test period, all subjects in the acacia group—whether their primary bowel complaint was diarrhea or constipation—experienced significantly greater improvements in overall IBS symptoms than did those in the control group.  For the subgroup of patients with diarrhea-predominant IBS, improvement in bowel habit satisfaction was significantly higher in those who consumed the composite yogurt with added acacia fiber.

Moss Nutrition Acacia Fiber is made with Fibregum, a premium, purified raw material and the first acacia fiber to be certified FODMAP-Friendly.  FODMAP is an acronym standing for Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols, e.g. carbohydrates fermented in the large intestine by gut microbes.  Foods high in FODMAPs include fiber-rich starches such as beans, wheat and other grains, high-fructose fruits such as apples, peaches and pears, and a number of vegetables including onions, garlic, cauliflower and yams.  Many studies suggest a low-FODMAP diet may help improve IBS symptoms.  However, a drawback of the diet is its relative absence of healthy fiber, indicating a role for FODMAP-friendly Acacia Fiber in patients following a low-FODMAP diet.

How should you take Acacia Fiber?

Compared to other soluble fiber products, advantages of acacia fiber include its easy mixability in cold water and its mild, virtually tasteless flavor.  As an alternative to dissolving the product in water, Acacia Fiber may be added to shakes or smoothies, or sprinkled on moist foods such as oatmeal or yogurt.  

Individuals unaccustomed to consuming fiber supplements may wish to begin taking Acacia Fiber in half servings and increase by one half teaspoon amounts, every few days, to allow for the gradual establishment of GI tolerance, and until desired results are achieved.  Increased water intake should accompany increases in Acacia Fiber dosage. 1-2 scoops twice a day typically works well but you can take all 4 scoops at once if that works for your gut. Like Flax Fiber, Acacia Fiber can be taken with or without food.

How to put all this together?

In summary, I would recommend trying the Flax Fiber first and if that doesn’t work for you try the Acacia Fiber.  If the Flax Fiber does work for you and you’ve been taking it for a month or two, you could try switching to the Acacia Fiber to see how you do.  You may notice other benefits that the flax fiber didn’t give you. Once your gut is functioning as well as you’d like it to be, try weaning yourself off of the fiber supplement to see if your gut will function well without it.  Or, you could continue on the fiber supplement and try adding in some prebiotics such as inulin, arabinogalactan, and beta-glucan for potentially even greater improvements. I’ll cover prebiotics in detail in another article.

Finally, if neither of these fiber supplements work for you, psyllium husk fiber would be my third choice which is an insoluble fiber that is least likely to cause gas and bloating but since it is insoluble it can be more irritating to your gut lining.  Psyllium does seem to work fine for individuals who can’t tolerate flax or acacia so it is a viable option when nothing else works. Psyllium powder doesn’t mix well so I like the capsules from NOW on Amazon.com which can be easily swallowed with a large glass of water.  1-3 capsules, 1-3 times a day with or without food is a standard dose.

Fiber supplements can be the missing link to healing your gut and keeping it functioning well so give these a try if your gut is in the right place and you want to heal it to the next level.

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