What Is Alpha Galactosidase? The Enzyme That Splits Galactans

Alpha galactosidase, also written as α-galactosidase, is an enzyme that splits galactans such as raffinose and stachyose into smaller sugars (1). These sugars are found in beans, lentils, and some vegetables, and they are known to cause flatulence (2). In your body, alpha galactosidase has no digestive job of its own: the carbohydrate-digesting enzymes of your small intestine do not include it (3), so these sugars travel on to your large intestine.

This page is part of our guide to digestive enzymes. Below you will learn what alpha galactosidase is, what happens to galactans in your body, which foods contain them, and where you find the enzyme in our products.

written and reviewed by Anouk Martini (registered dietician)

In short

Alpha galactosidase is an enzyme that splits galactans, such as raffinose and stachyose, into smaller sugars (1).
Galactans are found in beans, lentils, and some vegetables, and they can cause flatulence (2).
The carbohydrate-digesting enzymes of your small intestine do not include alpha galactosidase (3).
Alpha galactosidase is in our products Fibractase 1200, Fodmix, Carbostarch, and Enzymix.

What is alpha galactosidase?

An enzyme is a protein that speeds up a chemical reaction. Alpha galactosidase speeds up the splitting of a specific link in galactans: it releases galactose from sugars such as melibiose, raffinose, and stachyose (1). These raffinose family sugars are common in plants, especially in legumes (2).

Alpha galactosidase is also used in supplements. The alpha galactosidase in our products comes from Aspergillus niger, a fungus, and our products are suitable for vegetarians and vegans.

What does alpha galactosidase do in the body?

In your body, alpha galactosidase has no natural digestive role. This is what happens to galactans instead:

They arrive in your gut. Beans, lentils, and some vegetables contain raffinose and stachyose (2).
Your small intestine cannot split them. Your own enzymes for carbohydrates are the amylases, maltase-glucoamylase, and sucrase-isomaltase (3).
They reach your large intestine. Bacteria there help break down what is left (4). The raffinose family sugars are known to cause flatulence, and they can also feed helpful bacteria (2).

When you take an alpha galactosidase supplement with a meal, the enzyme adds a tool your body does not have. Alpha galactosidase helps with the digestion of complex carbohydrates by breaking them down into smaller sugars in the small intestine.* This makes them easier to digest and reduces the risk of gas formation.*

Which foods contain galactans?

Galactans, including raffinose and stachyose, are found in:

Beans, lentils, chickpeas, and peas
Soy products
Some vegetables, such as cabbage, Brussels sprouts, and asparagus
Some whole grains

When might alpha galactosidase help?

Some people take alpha galactosidase with meals that contain beans, lentils, or similar foods. Age, diet, lifestyle, and stress can all affect how well digestion works, and so do the size and type of a meal. Alpha galactosidase is not a replacement for a balanced diet, and it does not treat a medical condition.

Not sure whether a supplement fits you? Talk to a doctor or dietitian.

Where is alpha galactosidase in our products?

Alpha galactosidase is in four Intoleran products:

Fibractase 1200 contains alpha galactosidase (1200 u). It helps with the digestion of complex carbohydrates.* It is suitable for vegetarians and vegans and free of soy and gluten.
Fodmix contains alpha galactosidase (1200 u), xylose isomerase (7500 u), lactase (10,000 FCC), and invertase (500 u). Fodmix helps reduce occasional gas, bloating, and discomfort, allowing you to enjoy meals without restrictive diets.*
Carbostarch contains alpha galactosidase (1200 u), lactase (10,000 FCC), gluco-amylase (2500 u), and invertase (7500 u). It can help to digest lactose, complex carbohydrates, sucrose, and starch.*
Enzymix is a blend of nine digestive enzymes that support the breakdown of carbohydrates, proteins, fats, lactose, and plant fibers.* It contains alpha galactosidase (750 IU).

Looking for the supplement itself? Read more about the alpha galactosidase supplement.

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Not sure which enzyme you need?

Digestive enzymes each have their own job. Answer a few questions in our supplement advisor and see which products fit your situation. You can also ask our dietitians a question.

When should you talk to a doctor or dietitian?

Do your symptoms persist, are you losing weight without trying, or are you cutting out more and more foods? Talk to your doctor or a dietitian. A supplement does not replace medical advice.

Galactans are one kind of carbohydrate. Cellulase works on plant fiber, and invertase works on sucrose, or table sugar. See all of our digestive enzymes.

Sources

Bhatia S, Batra N, Singh J. Production, purification, characterization, and applications of α-galactosidase from Bacillus flexus JS27 isolated from Manikaran hot springs. Prep Biochem Biotechnol. 2023;53(4):366-83. doi:10.1080/10826068.2022.2095572
Elango D, Rajendran K, Van der Laan L, Sebastiar S, Raigne J, Thaiparambil NA, et al. Raffinose family oligosaccharides: friend or foe for human and plant health? Front Plant Sci. 2022;13:829118. doi:10.3389/fpls.2022.829118
Mohan S, Eskandari R, Pinto BM. Naturally occurring sulfonium-ion glucosidase inhibitors and their derivatives: a promising class of potential antidiabetic agents. Acc Chem Res. 2014;47(1):211-25. doi:10.1021/ar400132g
National Institute of Diabetes and Digestive and Kidney Diseases. Your digestive system & how it works [Internet]. Bethesda (MD): National Institute of Diabetes and Digestive and Kidney Diseases; last reviewed 2017 Dec. Available from: https://www.niddk.nih.gov/health-information/digestive-diseases/digestive-system-how-it-works