What Helps Break Down Fructan?

October 31, 2025 •

4 min read

The human body is naturally incapable of digesting fructans, a type of carbohydrate, in the small intestine because it lacks the necessary enzyme. For those with sensitivities, understanding what helps break down fructan is key to managing uncomfortable symptoms like bloating, gas, and abdominal pain.

Quick Summary

This guide details effective methods for managing fructan sensitivity, including specialized digestive enzymes, dietary adjustments, and food preparation techniques for improved digestion.

Key Points

Enzyme Supplements: Specialized supplements containing fructan hydrolase can be added to meals to break down fructans, preventing them from fermenting in the colon.
Low-FODMAP Diet: A short-term elimination diet can help identify personal fructan triggers and tolerance thresholds under a dietitian's guidance.
Sourdough Fermentation: The long fermentation process of traditional sourdough bread reduces its fructan content, offering a more tolerable wheat alternative.
Oil Infusion: Creating garlic-infused oil is an effective way to get the flavor of garlic without the water-soluble fructans that cause digestive issues.
Strategic Swaps: Using low-fructan alternatives like the green parts of scallions, rice, quinoa, and certain fruits can greatly reduce fructan intake.
Gut Bacteria's Role: The fermentation of fructans by gut bacteria is the source of digestive symptoms in sensitive people, though it is a normal process.
Hydration and Mindful Eating: Simple lifestyle changes like drinking plenty of water and eating slowly can aid overall digestion and minimize symptoms.

The Fructan Digestion Challenge

Fructans are a type of fermentable oligosaccharide, or FODMAP, found in a wide variety of healthy foods like wheat, garlic, onions, asparagus, and chicory root. Unlike other carbohydrates, the human digestive system lacks the enzyme required to break the specific chemical bonds in fructans during digestion in the small intestine. Consequently, these carbohydrate chains travel largely intact to the large intestine, where they are fermented by gut bacteria. This process produces gas and draws water into the colon, which can trigger painful and uncomfortable symptoms in sensitive individuals, such as bloating, abdominal pain, and diarrhea.

Targeted Enzyme Supplements

One of the most direct and effective ways to address fructan intolerance is with a targeted digestive enzyme supplement.

Fructan Hydrolase (Inulinase): This is the key enzyme that the human body lacks. Supplements containing fructan hydrolase are specifically designed to break down the fructan molecules in food. These are often sold as tasteless powders that are mixed directly into meals containing fructans. By doing so, the enzyme acts in the stomach and small intestine, degrading the fructans into smaller, more digestible sugars before they reach the colon to ferment.
Other Enzymes: Some multi-enzyme products may contain alpha-galactosidase, which helps break down other FODMAPs like GOS found in legumes, but it is not effective for fructans in garlic or onion. When choosing a supplement, it is crucial to select one that contains specific fructan-targeting enzymes.

The Low-FODMAP Diet: A Diagnostic Tool

For many with irritable bowel syndrome (IBS), the low-FODMAP diet is a clinically proven method for identifying and managing trigger foods. The diet is typically structured in three phases:

Elimination Phase: For 2–6 weeks, all high-FODMAP foods are removed to reduce symptoms. This gives the gut a chance to rest and heal.
Reintroduction Phase: Fructan-containing foods are systematically reintroduced one group at a time to identify an individual's specific triggers and tolerance levels.
Personalization Phase: Based on the reintroduction findings, a long-term eating plan is developed that restricts only the problematic foods while allowing for maximum dietary variety.

It is important to note that the low-FODMAP diet is restrictive and is not intended for long-term use. A registered dietitian can provide guidance to ensure nutritional needs are met throughout the process.

Food Preparation and Culinary Strategies

Certain culinary techniques can also help reduce the fructan content of high-FODMAP foods, making them more tolerable.

Sourdough Fermentation: The bacteria used in traditional, long-fermented sourdough bread reduce the fructan content in wheat, making it a lower-fructan alternative to regular wheat bread.
Garlic-Infused Oil: Fructans are water-soluble, not fat-soluble. By infusing garlic cloves in oil and then removing the solids, you can capture the garlic flavor without the fructans.
Leaching: The fructans in certain foods, like canned beans or lentils, can be reduced by rinsing them thoroughly. For onions and leeks, the green parts of scallions or leeks contain fewer fructans than the white bulbs and can be used for flavor.

Comparison of Fructan Management Methods


Method	How it Works	Pros	Cons
Digestive Enzymes	Supplements containing fructan hydrolase break down fructans directly in the stomach and small intestine.	Offers immediate relief and greater dietary flexibility for those with sensitivities.	Can be expensive; effectiveness may vary depending on the product and dosage.
Low-FODMAP Diet	Temporarily eliminates and then systematically reintroduces foods to identify personal tolerance levels.	Gold standard for diagnosis and finding individual triggers.	Can be restrictive, requires careful planning, and is not recommended long-term.
Sourdough Fermentation	Beneficial bacteria break down fructans during the long fermentation process.	Allows enjoyment of wheat-based bread with reduced fructan content.	Not all sourdough is made the same; fermentation time is key.
Food Preparation	Uses techniques like oil infusion or rinsing to remove fructans.	Provides flavorful, low-fructan alternatives to common ingredients.	Requires extra preparation steps; does not remove all fructans from food.

Dietary Adjustments and Low-Fructan Swaps

For those managing fructan intolerance, making smart substitutions can significantly reduce symptoms. While eliminating all high-fructan foods is often the first step, finding suitable alternatives is crucial for a varied and enjoyable diet.

Common High-Fructan Foods:

Grains: Wheat, rye, barley, couscous
Vegetables: Onions, garlic, shallots, leeks (white part), asparagus, artichokes, chicory root
Fruits: Ripe bananas, watermelon, nectarines
Legumes: Most beans, lentils, and chickpeas (especially dried)
Hidden Fructans: Inulin or chicory root added to processed foods like snack bars and fiber supplements.

Low-Fructan Food Alternatives:

Grains: Quinoa, rice, oats, millet, sourdough bread (if properly fermented)
Vegetables: Green parts of scallions and leeks, chives, bell peppers, carrots, cucumber, potatoes
Fruits: Unripe bananas, blueberries, grapes, oranges, strawberries
Legumes: Canned and rinsed chickpeas or lentils (small servings), tempeh
Flavoring: Garlic-infused oil, cumin, paprika, basil, ginger

Conclusion: A Personalized Approach to Fructan Digestion

Effectively managing fructan intolerance is a highly personalized journey. While there is no single food that helps break down fructan, a combination of dietary adjustments, targeted enzyme supplements, and mindful preparation can lead to significant symptom relief. Digestive enzymes containing fructan hydrolase offer a practical solution by assisting the body with digestion where it is naturally deficient. Meanwhile, a structured low-FODMAP diet, guided by a dietitian, remains the gold standard for diagnosis and personalized eating plans. Ultimately, understanding your body's specific tolerance levels and adopting a multifaceted approach is key to enjoying a broader, healthier diet without digestive distress. For more information, the Monash University FODMAP blog is an excellent resource for dietary management.

Frequently Asked Questions

Fructan intolerance occurs when individuals experience digestive symptoms like bloating, gas, and pain after consuming foods rich in fructans. This happens because the human body lacks the enzyme to digest them effectively, leading to fermentation by gut bacteria.

The enzyme that helps break down fructans is called fructan hydrolase, or inulinase. It is not produced naturally in the human body, but can be taken as a supplement, such as FODZYME, to aid digestion.

Certain food preparation methods can reduce fructan levels. Using garlic-infused oil allows for flavor without the fructans, as they are not fat-soluble. The fermentation process in sourdough bread also significantly lowers fructan content.

No. Many people who react to wheat products believe they have gluten sensitivity, but are actually reacting to the fructans in the wheat. Fructan is a carbohydrate, while gluten is a protein, and they trigger different bodily responses.

Probiotics may help balance the gut microbiome, but results for fructan intolerance can be mixed. As fructan intolerance is caused by fermentation, some probiotics could potentially worsen symptoms in some individuals, while others, like certain Bifidobacterium strains, may offer relief.

Many grains and vegetables are low in fructans, including quinoa, rice, oats, potatoes, and the green parts of scallions. Fruits like unripe bananas, blueberries, and strawberries are also low-fructan options.

The low-FODMAP diet is designed as a temporary tool to identify specific food triggers. Long-term elimination is not recommended, as it can unnecessarily restrict a healthy, varied diet. The goal is to identify your personal tolerance levels for a more liberal diet.