Benefiber is made of wheat dextrin, a soluble fiber derived from wheat starch. Each standard serving (one tablespoon, or 4 grams of powder) delivers 3 grams of soluble fiber and 20 calories. Despite coming from wheat, the product is processed to contain less than 20 parts per million of gluten, which meets the FDA threshold for a gluten-free label.
What Wheat Dextrin Actually Is
Wheat dextrin starts as ordinary wheat starch. During manufacturing, the starch is broken down using a combination of acid and heat, which splits the long starch chains into shorter fragments. Those fragments then reconnect into highly branched structures that dissolve easily in water. This processing is what transforms an indigestible starch into a fiber that mixes invisibly into beverages and soft foods without changing the taste, texture, or color.
The result is a non-viscous soluble fiber. That distinction matters. Unlike some fibers that thicken into a gel when mixed with liquid (think of the way psyllium-based products like Metamucil turn gloopy in a glass of water), wheat dextrin stays thin. You can stir it into coffee, juice, oatmeal, or soup and barely notice it’s there.
How Wheat Dextrin Works in Your Gut
Because wheat dextrin resists digestion in your stomach and small intestine, it arrives in your colon intact. There, gut bacteria ferment it completely. This fermentation is what gives wheat dextrin its prebiotic properties: it feeds beneficial microbes rather than simply adding bulk to stool.
Research published in Frontiers in Nutrition found that wheat dextrin increased the abundance of several groups of beneficial gut bacteria, including Bifidobacterium, Parabacteroides, and Fusicatenibacter. Bifidobacterium in particular is one of the most well-studied “friendly” bacteria associated with healthy digestion and immune function. The fermentation process also produces short-chain fatty acids like propionate and acetate, which serve as fuel for the cells lining your colon and play a role in regulating inflammation. Fiber mixtures with the highest proportion of wheat dextrin showed the strongest propionate-producing effect in lab simulations.
How It Compares to Psyllium Fiber
The two most common over-the-counter fiber supplements use very different ingredients. Benefiber uses wheat dextrin. Metamucil uses psyllium, a fiber extracted from the husks of the Plantago ovata plant. Both are soluble, but they behave differently in almost every other way.
- Texture: Psyllium forms a thick gel when mixed with water, so you need to drink it quickly before it thickens. Wheat dextrin is non-viscous and dissolves completely, making it easy to add to any food or drink.
- Fermentation: Wheat dextrin is fully fermentable, meaning gut bacteria break it down entirely. Psyllium is largely non-fermenting, so it passes through your system mostly intact and adds bulk to stool instead.
- Primary benefit: Because psyllium forms a gel, it’s often used to lower cholesterol and slow sugar absorption. Wheat dextrin’s full fermentability makes it better suited as a prebiotic that supports gut bacteria, though it also helps with regularity.
Neither is categorically better. They simply work through different mechanisms, and the right choice depends on what you’re trying to accomplish.
Nutritional Profile Per Serving
One tablespoon (4 grams) of Benefiber powder contains 20 calories, 4 grams of total carbohydrate, and 3 grams of soluble fiber. There’s no sugar, no fat, and no protein. The calorie count is minimal enough that even taking multiple servings a day won’t meaningfully affect your daily intake.
Gluten and Allergen Considerations
This is where Benefiber can cause confusion. It’s made from wheat, yet it carries a gluten-free label. The manufacturing process strips the gluten protein down to less than 20 parts per million, which is the FDA’s cutoff for calling a product gluten-free. Data from the NIH’s Dietary Supplement Label Database confirms this level. For most people with mild gluten sensitivity, this trace amount is unlikely to cause problems. However, if you have celiac disease, even sub-20 ppm levels may be a concern worth discussing with your gastroenterologist, since cumulative exposure from multiple gluten-free-labeled products can add up.
Who Can Take It
Children ages 6 through 11 can take up to one teaspoon mixed into 4 to 8 ounces of a beverage or soft food, up to three times daily. For children under 6, dosing should be individualized. Adults typically use one to two tablespoons per day, gradually increasing the amount over several days to give the gut time to adjust. Starting with too much soluble fiber at once commonly causes gas and bloating, since your gut bacteria need time to ramp up their fermentation capacity.