Is Locust Bean Gum a Prebiotic? Understanding its Impact on Gut Health

December 1, 2025 •

3 min read

Emerging research indicates that the soluble fiber found in locust bean gum possesses prebiotic properties, capable of nourishing beneficial gut bacteria. Derived from the seeds of the carob tree, this ingredient is primarily known for its thickening capabilities in the food industry, but its indigestible nature offers surprising benefits for the human microbiome.

Quick Summary

Locust bean gum functions as a prebiotic fiber, feeding beneficial gut microbes like Lactobacillus and Bifidobacterium to support a healthy microbiome. Its soluble fiber properties aid digestive health, regulate blood sugar, and can help manage certain gastrointestinal disorders by improving gut environment.

Key Points

Prebiotic Function Confirmed: Locust bean gum (LBG) is scientifically recognized as a prebiotic because it selectively ferments in the gut to feed beneficial bacteria like Bifidobacterium.
High in Soluble Fiber: This gum is a significant source of soluble dietary fiber, which remains undigested in the upper gut and functions as a food source for the gut microbiome.
Stimulates SCFA Production: Fermentation of LBG by gut bacteria produces short-chain fatty acids (SCFAs), which are crucial for maintaining the gut lining and reducing inflammation.
Supports Digestive Health: Its soluble fiber content aids in regulating digestion, helping to alleviate constipation and supporting overall gastrointestinal function.
Used in Infant Formula: LBG is safely and effectively used as a thickener in anti-reflux infant formulas, reducing the frequency of regurgitation.
Sourced from Carob Trees: LBG is a natural food additive derived from the seeds of the Mediterranean carob tree (Ceratonia siliqua).
Generally Safe: Classified as Generally Recognized as Safe (GRAS) by the FDA, LBG is a well-tolerated food additive.
May Cause Bloating: Some people might experience bloating or gas, especially when first introducing LBG into their diet, so a gradual increase is recommended.

What Exactly is Locust Bean Gum?

Locust bean gum (LBG), also known as carob bean gum, is a natural polysaccharide extracted from the seeds of the carob tree (Ceratonia siliqua). The endosperm of the seeds is processed into a fine powder used widely in the food industry as a thickener, stabilizer, and gelling agent in products like ice cream, sauces, and yogurts. LBG is a galactomannan, a type of fiber composed of mannose and galactose units, and is classified by the FDA as Generally Recognized as Safe (GRAS).

The Criteria for a Prebiotic

For a substance to be considered a prebiotic, it must meet specific scientific criteria:

It must resist digestion and absorption in the upper gastrointestinal tract.
It must be selectively fermented by beneficial bacteria in the large intestine.
This fermentation should stimulate the growth and activity of health-promoting bacteria, such as Bifidobacterium and Lactobacillus.
The process should result in positive health effects for the host.

Is Locust Bean Gum a Prebiotic? The Evidence

Scientific evidence confirms that locust bean gum acts as a prebiotic. As a soluble fiber, LBG passes through the stomach and small intestine undigested. In the large intestine, it is fermented by beneficial gut bacteria, serving as a food source.

A study published in Frontiers in Microbiology investigated the impact of a locust bean gum hydrolysate on mice with colitis. The results indicated that the hydrolysate increased the populations of beneficial bacteria like Lactobacillus and Bifidobacterium and boosted the production of short-chain fatty acids (SCFAs) such as butyric acid, which are important for gut health and reducing inflammation.

Fermentation and SCFAs

The fermentation of LBG by gut microbes produces SCFAs like acetate, propionate, and butyrate. Butyrate is a primary energy source for colon cells and helps maintain the gut barrier's integrity, which is crucial for preventing inflammatory conditions.

How LBG Compares to Other Prebiotic Fibers

Locust bean gum is a natural gum with prebiotic properties, often compared to other fibers like guar gum. Both are galactomannans, but their structural differences lead to varying effects on the gut microbiome.


Feature	Locust Bean Gum (LBG)	Guar Gum	Inulin	Fructo-oligosaccharides (FOS)
Source	Carob tree seeds	Guar plant seeds	Chicory root, garlic, onions	Chicory root, agave, bananas
Structure	Galactomannan with higher mannose to galactose ratio (~3.5:1)	Galactomannan with lower mannose to galactose ratio (~1.8:1)	Fructan polysaccharide	Shorter-chain fructan oligosaccharides
Solubility	Low solubility in cold water, requires heat	High solubility in cold water	Highly soluble	Highly soluble
Fermentability	Partially fermentable by gut bacteria	Readily fermented by gut bacteria	Easily fermented	Easily fermented
Viscosity	High viscosity, even at low concentrations	High viscosity	Low viscosity	Low viscosity
Effect on gut	Supports Bifidobacterium and Lactobacillus	Strong bifidogenic effect, less severe digestive symptoms than LBG	Highly bifidogenic	Highly bifidogenic

Health Benefits Associated with LBG's Prebiotic Effect

LBG's prebiotic action supports a healthy gut environment, contributing to potential health benefits:

Improved Digestive Regularity: As soluble fiber, LBG absorbs water, helping to soften stool and promote regular bowel movements, potentially easing constipation and IBS symptoms.
Blood Sugar Management: LBG's viscous nature can slow gastric emptying, moderating carbohydrate absorption and leading to a more gradual rise in blood sugar levels after meals.
Infant Reflux Reduction: LBG is used in infant formula to thicken it in the stomach, which helps reduce reflux and regurgitation.
Cholesterol Management: Soluble fiber in LBG can bind to bile acids, aiding their excretion and potentially helping to lower LDL cholesterol.

Considerations and Potential Side Effects

Though generally safe, large amounts of locust bean gum might cause digestive issues like bloating, gas, or cramps in some people, especially initially. It's best to start with small amounts. Individuals on certain medications should consult a doctor due to LBG's effect on nutrient absorption.

Conclusion

Scientific research supports classifying locust bean gum as a prebiotic because it stimulates beneficial gut bacteria and produces SCFAs. Its soluble fiber content aids digestive health by regulating bowel movements and slowing carbohydrate absorption. While known as a food additive for thickening, its benefits for the gut microbiome highlight its value as a functional ingredient. It is generally safe for improving gut health, but starting with small amounts is recommended.

Frequently Asked Questions

Yes, locust bean gum is widely regarded as safe for consumption. It has been designated as Generally Recognized as Safe (GRAS) by the U.S. Food and Drug Administration (FDA) and is a common food additive.

Locust bean gum is used as a natural thickener and stabilizer in many food products. You can find it in ice cream, sauces, salad dressings, baked goods, and some infant formulas.

Yes, as a soluble fiber, locust bean gum absorbs water in the digestive tract, forming a gel-like substance that helps soften stool and promote regular bowel movements, which can relieve constipation.

While generally safe, consuming large amounts of locust bean gum, especially when not accustomed to a high-fiber diet, can cause some digestive discomfort like gas, bloating, and cramps. It's best to introduce it gradually.

Yes, locust bean gum is effectively used as a thickener in anti-reflux infant formulas. Its gelling action helps thicken the contents in the stomach, reducing regurgitation episodes.

Both are galactomannan fibers, but they differ in structure and solubility. LBG requires heat for full solubility and is generally fermented more slowly, while guar gum is cold-water soluble and ferments more rapidly in the gut.

Yes, locust bean gum is naturally gluten-free and is often used in gluten-free baking to provide structure and moisture retention.

By increasing the viscosity of food, LBG slows down gastric emptying and the absorption of carbohydrates. This can lead to a more stable blood sugar response after meals.