Gut Immunity, Regularity & 6 Other Perks Of America’s Most Underconsumed Carb

Found exclusively in plants, fiber is a unique complex carbohydrate that passes through the body undigested. 

There are two main categories of fiber: Soluble fiber becomes a gel-like substance during digestion and helps collect and remove unwanted compounds (e.g., environmental toxins, cholesterol, extra hormones, waste) from the body. Insoluble fiber helps “get things moving”—i.e., it makes up the bulk of stool, promotes gut motility, and assists elimination.

Fiber is absolutely vital to gut health, as it supports the abundance, diversity, and balance of bacteria in your gut’s microbiome.

“Fiber is food for the many microbiota living in your gut,” says integrative registered dietitian Whitney Crouch, RDN, CLT. The colonies of microbes in your gut need adequate premium-grade “fuel” (i.e., prebiotic fibers) to help them grow and thrive. Fermentable fibers from complex carbohydrates (e.g., legumes, ginger, sweet potato, and flaxseeds) are the plant fodder needed to promote the composition and function of healthy gut microbiota.*

According to a 2017 research review from the Journal of the Academy of Nutrition and Dietetics, fiber is critical in supporting digestive regularity and gut motility2 (i.e., the movement of food through the digestive tract and out of the body).* 

Both types of fiber are essential to maintaining a healthy digestive system: Soluble fiber helps build stool “bulk” while insoluble fiber helps speed up transit time, registered dietitian Jess Cording, M.S., R.D., CDN explains.

Key prebiotic fibers help strengthen gut barrier integrity and enhance gut immunity by promoting SCFA production.* “The bacteria in the gut ferment fibers, producing gut-supportive short-chain fatty acids (the most well-known being butyrate),” Crouch says.

Per a 2018 Advances in Nutrition review, butyrate is especially beneficial for sustaining intestinal barrier function3 and mucosal immunity and resilience of the gut lining, which covers significant surface area inside our bodies and is the second line of immune defense (after the skin).

In fact, most of your immune system is located in your gut—approximately 70% to 80%4 of immune cells reside in the GI tract, according to a 2021 Nutrients review!* Prebiotic fibers and probiotics are integral in sustaining healthy gut-immune function by supporting the integrity and resilience of the gut lining, promoting SCFA synthesis, and bolstering gut microbiome diversity and abundance.*

We’ve already touched on digestive regularity and gut motility, but fiber is arguably most well-known for helping you have healthy poops. “Fiber is a bulking agent for a normal stool, one of the main factors in having a healthy and satisfying bowel movement,” Crouch shares.

In fact, a 2015 study from The Saudi Journal of Gastroenterology found that guar bean fiber (the type of fiber featured in mindbodygreen’s organic fiber potency+) helps reduce colonic transit time and increase the frequency and quality of bowel movements.* Simply put, getting adequate fiber is key to maintaining healthy stool form, color, and frequency.*

As mentioned earlier, soluble fiber effectively binds to cholesterol in the small intestine and removes it before it can enter the bloodstream. According to a meta-analysis from The American Journal of Clinical Nutrition, consuming two to ten grams of soluble fiber daily is associated with significant decreases5 in LDL (aka “bad”) and total cholesterol.* 

Guar bean fiber, specifically, has been found to increase HDL (“good”) cholesterol as well: In a 2016 Journal of Functional Foods study, healthy subjects saw a decrease in triglyceride and LDL cholesterol levels and a significant increase in HDL cholesterol6 after taking six grams of guar fiber with every meal (3 times a day) for one year.*

Insoluble fiber helps ease bloat and gas by moving food out of the stomach to be eliminated. Research shows that taking a daily guar fiber supplement, specifically, can help reduce colonic transit time7 and significantly reduce bloat and gas8 for individuals with gastrointestinal health concerns.*

If you’re experiencing gas and bloat, you may want to try upping your daily fiber intake—it can help soothe your stomach by encouraging healthy bowel movements and gut motility.

Researchers have found that fiber can help individuals feel full for longer, which is beneficial for those trying to resist snacking in between meals. The physical volume that insoluble (aka “bulk”) fiber creates certainly contributes to the feeling of fullness, but evidence suggests soluble fiber’s role in SCFA production offers further explanation behind this phenomenon.

Compared to other soluble fibers, guar bean fiber produces more of the SCFA butyrate, which plays an important role in satiety hormone synthesis, according to a 2015 study from the British Journal of Nutrition.* Whether eaten fresh or in a supplement powder (like mbg’s organic fiber potency+), guar beans deliver substantial dietary soluble fiber to support healthy butyrate production and appetite regulation.*

Fiber is a critical part of a healthy diet. Most Americans need to increase their dietary fiber intake, and both high-fiber foods and quality fiber supplements are effective and safe ways to add more fiber to your diet.

While there’s no tolerable upper limit for fiber intake, side effects can occur in certain individuals, such as those that have pre-existing gut health issues or increase their dietary fiber intake too rapidly. Crouch recommends drinking eight ounces of water for every 25 grams of fiber to proactively avoid unwanted side effects. 

Cording says most healthy adults need 25-35 grams of daily fiber. “If you’re working on increasing your fiber intake, do so gradually, and increase your fluid intake as well to help keep things moving through the GI tract,” she suggests. “For digestive comfort, spread your fiber intake throughout the day, aiming to have at least one high-fiber food per meal.”

Crouch says the most effective and nutrient-rich way to achieve your fiber intake goals is to include eight to ten servings of fruits and vegetables every day. She adds that limiting processed foods and choosing fruits and veggies with skin on (when appropriate) instead of peeled is another helpful way to up your fiber intake.

If you’re struggling to reach your dietary fiber intake through diet alone, you may benefit from a quality fiber supplement like mindbodygreen’s organic fiber potency+. “Anyone who has worked on their diet foundation first to reach the minimum recommended intake, or who has early satiety when eating a nutrient rich diet, still needs more fiber,” Crouch explains. This is where a supplement can be a beneficial addition to your daily regimen.*

Fiber is vital to a number of highly important gastrointestinal, cardiometabolic, and immune functions.* It’s likely that you, like most Americans, aren’t getting enough daily fiber. Increasing your fiber intake by adding high-fiber foods to each meal and adding a premium fiber supplement with efficacious dosage to your daily routine are both effective solutions to the nation’s overwhelming fiber gap.*

mindbodygreen’s organic fiber potency+ delivers six grams of insoluble, soluble, and prebiotic fiber (i.e., 21% of your daily fiber needs) from guar bean, green kiwifruit, and a mushroom trio (reishi, maitake, and oyster), plus a targeted probiotic strain for added gut health support!*