Sweeteners
Trehalose
Definition
What it is
Trehalose: a disaccharide used as a food additive since 2000; a 2018 Nature study linked widespread trehalose use to the rise of hypervirulent C. difficile strains in the gut.
On the label
How it appears on labels
- trehalose
Regulation
Regulatory status
No bans or restrictions are recorded for this ingredient in the jurisdictions clearlabel tracks (US, EU, UK, Canada, Japan, Australia/NZ, Brazil).
Explainer
In plain language
Trehalose is a naturally occurring sugar made of two glucose units, found in small amounts in mushrooms, honey, and some plants. As a food additive it adds mild sweetness, protects texture during freezing and drying, and helps stabilize other ingredients. It has been produced at commercial scale and used more widely in processed foods since around 2000.
Assessment
Why it is flagged
A 2018 study published in Nature associated the rise in dietary trehalose with the emergence of hypervirulent strains of Clostridioides difficile, a gut bacterium that can cause severe intestinal infection. The researchers reported that certain C. difficile strains gained the ability to use trehalose efficiently and that this may have contributed to their spread. That finding is debated: other researchers have questioned whether dietary trehalose reaches the colon in high enough amounts to drive this, and the link is a hypothesis about population-level trends rather than proof that eating trehalose harms an individual. Regulators including the FDA continue to recognize trehalose as safe. Clear Label flags it so the open research question is visible, not because harm from normal intake is established.
In the aisle
Where it commonly shows up
- Protein and snack bars
- Frozen and dried processed foods
- Some baked goods and pastries
- Coated and chewy candies
- Sugar-reduced or reformulated sweets
- Some processed meats and prepared meals
Practical
Reading the label
Trehalose is usually listed by name in the ingredient list. In some regions it can appear as the additive number E422's neighbor in labeling systems, but it is most reliably identified by the word trehalose itself.
Alternatives
If you want to avoid it
Some people who want to avoid it choose bars and sweets sweetened with more familiar sugars or with sweeteners tracked as separate Clear Label flags. Comparing ingredient lists across similar products usually shows which ones rely on it.
FAQ
Common questions
Does trehalose cause C. difficile infections?
No study has shown that eating trehalose causes infection in a person. A 2018 Nature study associated wider trehalose use with the spread of certain hypervirulent C. difficile strains, a population-level hypothesis that other researchers have since questioned.
Is trehalose approved for use in food?
Yes. Trehalose is recognized as safe by the FDA and permitted in many other markets, and it has been used as a food additive since around 2000.
Should gut-sensitive people watch for it?
Some people with sensitive digestion prefer to track it, since the research debate centers on the gut. Clear Label treats it as a pattern to test in your own food and symptom logs rather than a settled harm.
Citations
Sources
Citation
Primary reference
About this page: the definition, label names, severity, and regulatory chips come from the clearlabel ingredient taxonomy, the same data the scanner uses to score products. Research summaries describe associations reported in published studies, not diagnoses; individual responses vary. Scan any product with clearlabel to see which of its ingredients carry flags.