Trehalose

No E-numberSweetenersOrigin: Plant

Get a personal answer

Pick your family’s diets in the bar above.

Every diet

VeganYes

Food trehalose is made from starch with enzymes.

Gluten-freeDepends

Gluten-free when the starch source is corn or tapioca. A wheat-starch source would not be.

HalalYes

KosherYes

KetoNo

Trehalose is a caloric sugar.

Low-FODMAPYes

Trehalose is two glucoses, not a FODMAP sugar.

The short answer

Trehalose is a mild glucose-glucose sugar used in nutrition bars, dried foods and some pastries. It is not keto. It is vegan. A gluten-free answer depends on which starch the enzymes started from.

64/100

Use in moderation

Safe in small amounts; may bother some people or raise blood sugar.

E-numberNone

Comes fromPlant

What it doesSweeteners

Glycemic index—

Daily limitNot set

Also calledTrehalose, Mushroom sugar

Rules by country

🇺🇸 US FDAApproved

🇪🇺 European UnionNot evaluated as an additive

🇨🇦 Health CanadaNot evaluated as an additive

CaliforniaNo extra rules

The FDA accepted a GRAS notice for trehalose. Europe and Canada sell it as a food ingredient. It has no E-number on this page because it is not used here as a numbered additive. A 2018 Nature paper linked the sugar to the rise of some virulent Clostridioides difficile strains in the lab and in mice. That is a concern, not a finding that a pastry causes an infection.

Daily limit: Experts haven’t set a number because normal food amounts are far below any level of concern.

What is it?

The commercial process takes starch, breaks it down, and rebuilds the disaccharide with enzymes. The powder is white and about half as sweet as sucrose. It also protects proteins when foods are dried, which is why it shows up in dried fruit pieces.

Where it comes from: Trehalose is a sugar of two glucose units linked in a way that tastes milder than table sugar. Food-grade trehalose is made from starch with enzymes. Mushrooms and yeast make the same sugar, which is why dried mushrooms taste faintly sweet.

Why it’s in food

Sweetens mildly
Protects dried foods
Softens a pastry
Stabilizes a bar

Often found in

Nutrition barsDried fruit piecesBaked goodsSome ice creamsPowdered drink mixesImported Japanese sweets

Also listed as: Trehalose, Mushroom sugar

Health & gut impact

The C. difficile paperUnder study

A 2018 Nature study found that two epidemic strains of Clostridioides difficile can eat trehalose and that the sugar increased virulence in mice. It did not show that ordinary servings give people the infection.

Collins and colleagues, Nature, 2018

A real sugarConcern

Trehalose is caloric glucose. A milder taste makes it easy to use more of it. Keto plans count it as sugar.

Structure of trehalose as a glucose disaccharide

What can I use instead?

Sucrose

Ratio: Ordinary table sugar, sweeter per gram

Best for: Baking

Allulose

Ratio: A rare sugar with little blood-sugar rise

Best for: Keto baking

More sweeteners:

Acesulfame Potassium (Ace-K) E950Acesulfame potassium (Ace-K, E950) is a zero-calorie sweetener approved in the US, EU and Canada. EFSA re-checked it in 2025 and raised its daily limit. It's usually paired with sucralose or aspartame to hide a slightly bitter aftertaste.Use in moderation Advantame E969Advantame (E969) is an extremely intense sweetener related to aspartame. Regulators approve it, and the amount in a food is tiny next to the daily limit. It does not carry aspartame's phenylalanine warning at normal use.Generally safe Agave syrup (Agave nectar)Agave syrup is a plant sweetener that is mostly fructose. It barely moves blood sugar, and it is still sugar: skip it on keto and in a low-FODMAP elimination.Use in moderation AlluloseAllulose is a "rare sugar" that tastes like sugar but has almost no calories and doesn't raise blood sugar. It's keto-friendly and browns like real sugar in baking.Generally safe

Common questions

Is trehalose an artificial sweetener?

No. It is a sugar that yeast and mushrooms make. The food ingredient is produced with enzymes from starch.

Should people avoid it because of the 2018 study?

The study is a reason for researchers to keep looking. It is not a recall. This page leaves the score in the moderation band because the question is still open.

Is Trehalose safe?

Use in moderation (64/100). The FDA accepted a GRAS notice for trehalose. Europe and Canada sell it as a food ingredient. It has no E-number on this page because it is not used here as a numbered additive. A 2018 Nature paper linked the sugar to the rise of some virulent Clostridioides difficile strains in the lab and in mice. That is a concern, not a finding that a pastry causes an infection.

Is Trehalose vegan?

Yes. Food trehalose is made from starch with enzymes.

Is Trehalose gluten-free?

Depends. Gluten-free when the starch source is corn or tapioca. A wheat-starch source would not be.

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Scientific sources & regulatory citations

Collins and colleagues, Nature, 2018
Structure of trehalose as a glucose disaccharide

CAS 99-20-7