At a glance
How does Cellulose gum / carboxymethylcellulose appear on a UK label?
Useful label-reading detail
Do not confuse CMC with unmodified cellulose or assume the amount from its position.
How it is classified
A cellulose-derived thickener/stabiliser and possible NOVA formulation marker. It is not classed as a FODMAP.
Why amount matters
The 2022 controlled-feeding study used 15 g/day for 11 days. An ingredient list normally cannot show whether a product approaches that exposure.
Evidence by study type
What do studies show about Cellulose gum / carboxymethylcellulose?
What was studied: Sixteen healthy adults completed tightly controlled diets for 11 days: 7 received 15 g/day CMC and 9 received no CMC.
What it cannot tell us: The sample was very small, exposure was defined and high, and the trial was not designed to prove IBS or chronic disease.
What human studies show about Cellulose gum / carboxymethylcellulose
In a small 2022 controlled-feeding study, 7 healthy adults received 15 g/day CMC and 9 received control diets. CMC modestly increased post-meal discomfort and changed microbiota and metabolite measures. A 2026 exploratory trial found lower short-chain fatty acids with CMC but no overall inflammatory or metabolic endpoint difference between its small arms.
SourcesUK approved-additives listGreat Britain food-additive registerEFSA cellulose assessment2022 CMC controlled-feeding study2026 emulsifier trial2015 mouse emulsifier study
What animal or laboratory studies suggest about Cellulose gum / carboxymethylcellulose
Animal studies report mucus and inflammatory effects under experimental conditions. Microbiota, metabolite and mucus interactions are plausible pathways, not proof of a clinical outcome at typical exposure.
SourcesUK approved-additives listGreat Britain food-additive registerEFSA cellulose assessment2022 CMC controlled-feeding study2026 emulsifier trial2015 mouse emulsifier study
What we still do not know about Cellulose gum / carboxymethylcellulose
Long-term effects at common exposure and which people might respond remain uncertain.
Great Britain regulatory context
E466 is authorised in Great Britain. EFSA’s 2022 follow-up concluded that a numerical acceptable daily intake was not needed and found no safety concern at reported general-population uses, while noting remaining data gaps for some special uses.
SourcesUK approved-additives listGreat Britain food-additive registerEFSA cellulose assessment2022 CMC controlled-feeding study2026 emulsifier trial2015 mouse emulsifier study
Common questions
Questions people ask about this label
Are cellulose gum, CMC and E466 the same?
They are common and technical label names for carboxymethylcellulose. They are not the same as every form of cellulose.
SourcesUK approved-additives list
Did the human study prove CMC causes IBS or chronic disease?
No. It found short-term microbiota, metabolite and discomfort changes in a very small controlled study. It did not diagnose IBS or measure long-term disease outcomes.
Can a label show whether my exposure matches the study?
Usually not. The trial supplied 15 g/day; commercial labels normally confirm presence without giving CMC grams.
References
Sources used for this page
- Food Standards Agency, Approved additives and E numbers
- Food Standards Agency, Register of food-additive authorisations for Great Britain
- EFSA FAF Panel (2022), Follow-up assessment of celluloses including E466
- Chassaing et al. (2022), Controlled-feeding study of carboxymethylcellulose
- Wellens et al. (2026), Placebo-controlled trial of five dietary emulsifiers
- Chassaing et al. (2015), Dietary emulsifiers impact the mouse gut microbiota
Written and evidence-checked by the GutGuard editorial team. We favour official UK guidance, systematic reviews and primary human research, and label animal, laboratory and exploratory findings clearly. Read our editorial method.