Psyllium vs. Dextrin: Which Is the Better Fiber Supplement?

Are you getting enough fiber? Many people in the United States only get half of the recommended amount. The Academy of Nutrition and Dietetics recommends 14 grams (g) of fiber per 1,000 calories you eat. But U.S. adults are only getting 7.6 to 8.6 g of fiber per 1,000 calories, according to the National Health and Nutrition Examination Survey.

Your first choice for fiber should be whole plant foods. But because low fiber intake is common, fiber supplements can help you make up the difference. You have many choices when it comes to fiber supplements, so staying up to date on the different types is key to choosing one. Two options include psyllium and dextrin.

What Is Psyllium?

Psyllium, also known as psyllium husk, comes from the psyllium plant Plantago ovata, according to review on psyllium.

The majority of psyllium is soluble fiber, but it naturally contains a small amount of insoluble fiber as well. Psyllium is used primarily as a laxative. It’s the main ingredient in popular stool-softening products such as Metamucil, according to Cleveland Clinic.

What Is Dextrin?

Dextrin is a type of soluble fiber — often labeled as resistant dextrin or resistant starch — that producers make from starchy foods, such as wheat or corn, according to research. The large intestine ferments dextrin easily, which can provide gut health benefits.

Dextrin is only a soluble fiber. It does not contain any insoluble fiber. It’s the main ingredient in Benefiber.

Psyllium vs. Dextrin Benefits

Here’s how the benefits of psyllium and dextrin stack up.

Heart Health

The way psyllium behaves as it moves through the digestive tract has a significant influence on its benefits. And it’s the gel-like properties of psyllium that contribute to its cholesterol-lowering effects, according to a review on psyllium.

In fact, psyllium is one of two fibers (beta-glucan is the other) that holds a U.S. Food and Drug Administration (FDA) health claim for reducing the risk of heart disease by lowering cholesterol.

Fewer studies have examined dextrin, and it doesn’t have as many links to health benefits. A research review published in 2022 states that resistant starch, such as dextrin, may improve blood lipids, but the research so far is inconclusive.

Gut Health

Psyllium can also produce short-chain fatty acids (SCFA) — namely butyrate, a postbiotic — when people with constipation take it as a supplement, according to research. Researchers suggest that psyllium improves gut health by promoting the growth of beneficial bacteria.

Dextrin has been most widely studied for its prebiotic properties, which can support fermentation and improve gut health. Research is now exploring a possible link between dextrin and SCFA production, according to a review published in 2021.

Blood Sugar Control

Psyllium has been studied for its effect on blood sugar control, especially in those with type 2 diabetes. People with diabetes taking 10.5 grams of psyllium daily — with doses separated throughout the day — lowered their fasting blood sugar and hemoglobin A1C levels with eight weeks of supplementation, according to a review published in 2022.

Dextrin does not have any conclusive evidence supporting its use as a supplement for blood sugar control.

Weight Management

According to StatPearls, many studies on psyllium’s potential for weight management have found it doesn’t result in significant weight loss. However, in more recent studies, psyllium husk had a dose-dependent effect on weight loss: Higher doses led to greater weight loss, with 30 g of fiber or more being the most effective compared with placebo. An eight-week trial of taking 10.5 g of psyllium daily also led to significant weight loss.

Dextrin increases feelings of fullness, which may help with weight management, according to a small study published in 2021. However, a study published in 2020 shows the opposite effect: Supplementing with dextrin did not affect appetite regulation. More research is necessary to demonstrate dextrin’s benefits in this area.

Dosage

Take a fiber supplement in addition to the fiber you already get from whole foods, according to Mayo Clinic. It’s best not to get all of your fiber from dextrin, psyllium, or any other type of fiber supplement.

If you’re concerned, start with a half dose and gradually increase to a full dose if you don’t experience any side effects. Once your body becomes accustomed to that amount, you can gradually increase your fiber intake.

Potential Risks or Interactions

While fiber supplements may be a helpful way to boost fiber intake, some cautions apply.

Gastrointestinal Discomfort

As with any supplement or medication, psyllium and dextrin fiber can have unwanted side effects. Although fiber supplements are generally safe, they can cause side effects such as gas and bloating, especially at first, according to Mayo Clinic.

Although increasing your fiber intake can have several health benefits, it’s possible to consume too much. Some of these side effects come from simply taking too much fiber. Other times, the discomfort comes from adjusting to the regimen. Slowly introducing fiber may curb side effects, according to the Academy of Nutrition and Dietetics.

Take your fiber supplement with a glass of water, according to Cleveland Clinic, especially with psyllium, since it can thicken when mixed. Also drink water throughout the day to help alleviate any side effects from adding more fiber to your diet.

Fiber May Not Mix With Medical Conditions

People with celiac disease or gluten intolerance should avoid wheat dextrin, as it may contain gluten, according to the nonprofit Beyond Celiac.

People with Crohn’s disease or a history of intestinal blockages should speak with their doctors before taking a fiber supplement.

Timing Matters

You should also check with your doctor or pharmacist before introducing a fiber supplement to ensure it does not interfere with any prescriptions. Fiber supplements should not be taken within one to two hours of your medication.

Lead Contamination

All of the psyllium brands we’ve recommended have passed ConsumerLab tests for safety, including lead. Many psyllium supplements have more than the allowable limit for lead.

According to Harvard Health, when choosing a supplement, especially psyllium, make sure it has undergone third-party testing by an organization such as the US Pharmacopeia.

Psyllium vs. Dextrin: Which Is the Best Fiber Supplement?

Psyllium and dextrin are both effective supplements to get you additional fiber. It comes down to choosing a type of fiber that will deliver results for the conditions you hope to improve.

Discussing your fiber choice with your doctor or dietitian can help you ensure it’s appropriate and will not interfere with any current conditions or medications.

Fiber Basics

When you eat any food, your body breaks down macronutrients, like carbohydrates and protein, so it can absorb them. Your body also takes in micronutrients, such as vitamins and minerals. But fiber is the part of plant foods that the human body doesn’t absorb. Instead, fiber passes through your body mostly intact.

According to the Academy of Nutrition and Dietetics, fiber provides many benefits, like slowing digestion to support weight management and blood sugar control, maintaining regular bowel movements, and helping clear cholesterol from your body to reduce the risk of heart disease.

There are two types of fiber, according to MedlinePlus:

• Soluble Fiber This type dissolves in water and forms a gel-like substance. It can sometimes slow digestion. But because of its ability to pull in water, it can also have a laxative effect.
• Insoluble Fiber Sometimes called the “roughage” in your diet, it helps form bulky stool and can help you pass it easier.

Whole plant foods contain a healthy mix of the two types of fiber for optimal digestion and health benefits.