What Does Invertase Do for the Body? Understanding Its Role in Sugar Metabolism

December 13, 2025 •

3 min read

The human body possesses specialized enzymes to digest sucrose, a process sometimes mistakenly attributed to invertase. A more accurate look at what invertase does for the body reveals a role often connected to external sources like diet and supplements, rather than an internally produced digestive aid.

Quick Summary

The body’s sucrase-isomaltase enzyme breaks down dietary sucrose into glucose and fructose for energy. Invertase, an enzyme from external sources like yeast, performs a similar function and is used in food production and supplements, especially for enzyme deficiencies.

Key Points

Body's Sugar Enzyme: The human body uses the sucrase-isomaltase enzyme, not invertase, to break down dietary sucrose in the small intestine.
External Source: Invertase is an enzyme primarily found in yeast, fungi, plants, and honey, and is widely used in the food industry to process sugars.
Digestion vs. Supplement: While both enzymes hydrolyze sucrose into glucose and fructose, the body's sucrase-isomaltase is essential for normal digestion, whereas invertase is used externally or as a supplement.
Deficiency Connection: For individuals with Congenital Sucrase-Isomaltase Deficiency (CSID), specific enzyme replacement therapies containing sacrosidase are used to manage symptoms, not general invertase supplements.
Industrial Use: The primary uses of commercial invertase are in confectionery and baking to prevent sugar crystallization, create soft fillings, and keep baked goods moist.

The Body's Native Sugar-Breaking Enzymes: Sucrase-Isomaltase

While the name "invertase" is commonly used, the human body primarily relies on a different, more complex enzyme system to break down sucrose. This system centers on the enzyme complex called sucrase-isomaltase, produced in the small intestine.

Sucrase-isomaltase is an integral protein located on the brush border membrane, the layer of cells lining the small intestine. When sucrose, or table sugar, enters the small intestine, this enzyme complex cleaves the glycosidic bond connecting its two monosaccharide components: glucose and fructose. The resulting simple sugars can then be easily absorbed through the intestinal wall into the bloodstream to be used for energy.

The Importance of Sucrase-Isomaltase

The sucrase portion of the enzyme is responsible for hydrolyzing sucrose, but the complex also includes an isomaltase component. Isomaltase plays a key role in breaking down starches and other complex carbohydrates into absorbable glucose. This dual functionality makes the body's native enzyme system highly efficient at processing a wide variety of dietary sugars and starches.

Invertase: An Enzyme from External Sources

In contrast to the body's own digestive enzymes, invertase (or β-fructofuranosidase) is an enzyme derived from external sources, most notably baker's yeast (Saccharomyces cerevisiae), fungi, and plants. Invertase performs the same chemical reaction as the sucrase portion of the sucrase-isomaltase complex—hydrolyzing sucrose into glucose and fructose.

Invertase is widely utilized in the food industry for a variety of purposes:

Confectionery: It is used to create soft-centered candies, creme eggs, and chocolate-covered cherries. The enzyme is added to the hard sugar filling, which then softens over time as the invertase converts the sucrose into liquid glucose and fructose.
Baking: Bakers add invertase to recipes to prevent sugar crystallization, which can make baked goods smoother and more moist, extending their shelf life.
Honey Production: Bees naturally produce invertase to convert nectar into honey. This is why honey contains a supersaturated mixture of glucose and fructose, which resists crystallization.

Invertase and the Body's Sucrase-Isomaltase: A Comparison

While they perform the same function on sucrose, invertase and sucrase-isomaltase differ in their origin, structure, and mechanism of action within the body.


Feature	Invertase (External Source)	Sucrase-Isomaltase (Body's Enzyme)
Primary Source	Yeast, fungi, plants, honey	Small intestine lining cells
Location of Action	Food and supplements, industrial processes	Brush border of the small intestine
Biochemical Type	β-fructofuranosidase (cleaves the β-2 fructosyl linkage)	α-glucosidase (cleaves the α-1,2 glucosyl and α-1,6 linkages)
Role in Digestion	Supplements may be used to aid sugar digestion	Essential for digesting dietary sucrose and starches

When Enzyme Deficiency Occurs: Congenital Sucrase-Isomaltase Deficiency (CSID)

For some individuals, the body's sucrase-isomaltase system is compromised. Congenital Sucrase-Isomaltase Deficiency (CSID) is a rare genetic disorder where the small intestine does not produce sufficient amounts of this crucial enzyme.

Symptoms of CSID often become apparent in infants when they begin consuming solid foods and include:

Chronic or intermittent diarrhea
Abdominal pain and bloating
Excess gas and cramping
Failure to thrive and malnutrition in severe cases

Without functioning sucrase, sucrose passes undigested into the large intestine. There, bacteria ferment the sugar, leading to gas, bloating, and watery diarrhea. The standard treatment for CSID is enzyme replacement therapy using sacrosidase, a form of sucrase derived from yeast, which helps break down sucrose when taken with meals.

The Role of Invertase Supplements

Beyond enzyme replacement therapy for CSID, invertase supplements are also available on the market. However, general use for improved digestion has limited clinical evidence. While the supplement provides the enzyme, the body's natural digestive processes in a healthy individual already efficiently handle sucrose. For those with confirmed deficiencies, a targeted medical product like sacrosidase is the recommended treatment, not over-the-counter invertase supplements. Inhaling invertase powder can cause respiratory irritation or allergic symptoms and should be handled with care.

Conclusion: The Body's Precise Digestive System

The inquiry "What does invertase do for the body?" reveals a nuanced answer. While external invertase from yeast and plants acts as a powerful sucrose-hydrolyzing enzyme, the healthy human body uses its own specialized sucrase-isomaltase complex for this task. The primary purpose of this native enzyme is to efficiently break down sucrose and starches for energy absorption. For those with a genetic deficiency in this enzyme, external supplementation with a therapeutic grade of sucrase is necessary for managing symptoms. Overall, understanding the specific roles of both external invertase and the body's own sucrase is key to a complete picture of sugar metabolism. More about Sucrase-Isomaltase Deficiency at NIH

Frequently Asked Questions

No, while both enzymes break down sucrose into glucose and fructose, they are biochemically different. Invertase cleaves the bond from the fructose end, while sucrase (part of the sucrase-isomaltase complex) cleaves it from the glucose end.

No, the human body does not produce invertase. It produces a similar but distinct enzyme complex called sucrase-isomaltase in the small intestine to digest sucrose.

The primary function of sucrase-isomaltase, produced in the small intestine, is to catalyze the final breakdown of dietary sucrose and starches into simple sugars like glucose and fructose so they can be absorbed into the bloodstream.

CSID is a rare genetic disorder where the small intestine lacks or has low levels of the sucrase-isomaltase enzyme. This leads to symptoms like diarrhea, gas, and bloating after consuming sucrose or starches.

While supplements containing invertase exist, there is limited clinical evidence supporting their use for general digestive improvement in healthy individuals. The body's natural enzymes are typically sufficient.

Invertase is widely used in confectionery and baking. It helps create soft, liquid centers in candies and keeps baked goods moist by breaking down sucrose into non-crystallizing sugars.

Yes, bees produce invertase naturally to convert the sucrose in nectar into the inverted sugar (glucose and fructose) that forms honey.