What Is Inulin? A Plain-English Guide to This Prebiotic Fiber

Inulin is a type of carbohydrate found in some plants and used as an added fiber in foods and supplements. Your small intestine does not fully digest it, so it can reach the large intestine, where gut microbes ferment it. That is why inulin is often described as a prebiotic fiber. It is also why it may cause gas or bloating for some people.

Quick answer

• Inulin is a fermentable fiber, not a probiotic: it is food that gut microbes can use, rather than live bacteria added to the gut.
• Its effects depend on the person, the food or supplement, and the amount consumed.
• Fermentation is a normal digestive process, but it can produce gas. Inulin is not a guaranteed way to relieve bloating or improve a health condition.

What is inulin?

Inulin is a family of plant carbohydrates called fructans. It occurs naturally in foods such as chicory root and some other plants, and food makers may also add it to products as a source of fiber. The FDA's scientific review of isolated and synthetic dietary fibers describes inulin as a soluble fiber that is not digested by human enzymes in the gastrointestinal tract and is fermented by microorganisms in the colon.

“Soluble” does not mean that every soluble fiber behaves the same way. The FDA review notes that inulin does not have the same viscosity or physical effects as typical soluble, viscous fibers. So it is better to think of inulin by its own properties rather than assume all fiber works alike.

Is inulin a prebiotic?

Inulin is commonly described as a prebiotic because gut microorganisms can use it. Prebiotics and probiotics are different: a prebiotic is a substance used by microorganisms, while probiotics are live microorganisms. The National Institutes of Health Office of Dietary Supplements lists inulin and related fructooligosaccharides as examples of carbohydrates that microorganisms in the gastrointestinal tract use as metabolic fuel.

That definition does not mean that every inulin-containing product has been shown to produce a particular health outcome. Evidence about an ingredient, a specific dose, or a food is not automatically evidence about every finished supplement.

Why can inulin cause gas or bloating?

When gut microbes break down carbohydrates that the small intestine has not fully digested, gas can be produced. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) explains that this process is one normal source of digestive gas. People differ in how much gas they notice and how bothersome it feels.

More fiber at once can also be uncomfortable for some people. NIDDK says some people have more gas symptoms when they consume too much fiber and suggests discussing persistent or bothersome symptoms with a health professional. If you are increasing fiber from foods or supplements, pay attention to how you feel and follow the product's directions; do not assume that a larger amount will work better.

How does inulin relate to Livera?

Livera's current product page describes its prebiotic fiber as a combination of inulin and pectin. That is the product's stated formulation, not evidence that the finished gummies have been clinically shown to treat bloating or another condition. The page does not specify how much of the total fiber comes from each ingredient. You can review the Livera product page for its current product information.

Disclosure: Livera publishes this educational article and sells the product linked above. Research on inulin by itself does not establish the effects of Livera's finished formula. A supplement is optional and is not a substitute for medical advice or treatment.

When should you ask a health professional?

Talk with a clinician if gas or bloating is persistent, changes suddenly, interferes with daily life, or occurs with other symptoms. NIDDK advises discussing gas symptoms that are bothersome or accompanied by concerns such as abdominal pain, constipation, diarrhea, or weight loss. A clinician or registered dietitian can help you decide whether a change in fiber makes sense for you.

Frequently asked questions

Is inulin the same as a probiotic?

No. Inulin is a fermentable fiber that gut microorganisms can use. Probiotics are live microorganisms. They are related concepts, but they are not interchangeable.

Can inulin make bloating worse?

It can contribute to gas for some people because it is fermented in the colon. Individual responses vary, and symptoms can have many causes. If symptoms persist or trouble you, ask a health professional rather than trying to self-diagnose.

Does inulin treat digestive problems?

This article does not establish a treatment effect. Studies of particular inulin preparations and amounts cannot be generalized to every person or to Livera's finished product.

The takeaway

Inulin is a plant-derived, fermentable fiber that gut microbes can use. That makes it a prebiotic, but it also means gas can occur, and individual responses differ. Livera's product page names inulin and pectin in its prebiotic fiber blend; ingredient research alone does not prove a benefit from the finished gummies.

Sources

• FDA: Science Review of Isolated and Synthetic Dietary Fibers
• NIH Office of Dietary Supplements: Probiotics Fact Sheet for Health Professionals
• NIDDK: Symptoms and Causes of Gas in the Digestive Tract
• NIDDK: Eating, Diet, and Nutrition for Gas in the Digestive Tract
• Livera: Current product information