Evidence-basedEditor-reviewedCited sourcesUpdated regularly
Surfactants & Emulsifiers

Cellulose Gum

Also known as: Carboxymethylcellulose, CMC, Sodium carboxymethylcellulose, E466

Plant cellulose made water-loving — the thickening fiber in ice cream, toothpaste, and the gut-permeability research debate.

  • By IngredientWiki Editorial Team
  • Fact-checked by IngredientWiki Editorial Team
  • Updated 2026-09-26
  • 2 min read

In short

Cellulose gum (carboxymethylcellulose, CMC) is cellulose — the structural fiber of plants — chemically modified with carboxymethyl groups to dissolve in water. That one change turns wood pulp into a versatile thickener, stabilizer, and texture agent found in ice cream, sauces, toothpaste, eye drops, and gluten-free baking. It is indigestible, passes through the gut, and is approved worldwide with an 'ADI not specified' safety designation — the regulator's strongest vote of confidence. Since 2015, however, it has shared the spotlight with polysorbate 80 in gut research: rodent studies at extreme doses show mucus-barrier thinning and microbiota shifts. Human relevance at dietary levels remains unproven, and no regulator has changed its position.

  • Water-soluble derivative of plant cellulose
  • Thickener/stabilizer in food, toothpaste, drugs, and baking
  • Indigestible fiber; 'ADI not specified' safety status
  • High-dose rodent studies: gut-barrier effects; human relevance unclear

What is Cellulose Gum?

Cellulose gum is wood pulp with a career change. Chemists add carboxymethyl groups to cellulose — the most abundant biopolymer on Earth — and the result dissolves in water to form slippery, stable gels that thicken ice cream, hold toothpaste together, and give gluten-free bread its crumb. It has been a food additive for a century with a spotless regulatory file. Its recent appearance in gut-health headlines comes from high-dose rodent studies pairing it with other emulsifiers; the science is worth understanding, but the exposure gap between those experiments and human diets is wide.

Where it comes from

Natural sources

  • Derived from cellulose of wood pulp or cotton linters
  • Modification: carboxymethyl groups make it water-soluble

How it's made

White powder; EU code E466; used at 0.1–2% in foods, 0.5–2% in toothpaste, and in pharmaceuticals.

What it does in products

  • Viscosity building and thickening
  • Stabilization of emulsions and suspensions
  • Ice-crystal control in frozen desserts
  • Film-forming and texture in gluten-free baking

Benefits

Food texture and stability

strong evidence

Prevents ice-crystal growth, stabilizes sauces, and substitutes gluten structure — a foundational processing function.

Soluble-fiber properties

strong evidence

Acts as an indigestible soluble fiber in the gut, contributing to stool bulk at higher intakes.

Regulatory safety record

strong evidence

JECFA assigns 'ADI not specified' — the strongest safety category — reflecting minimal absorption and no chronic toxicity findings.

Side effects & safety

Bloating or loose stools at very high intake (uncommon)Typical of all soluble fibers in large amounts.

Safety considerations

  • Safe in food at regulated levels.
  • May slow absorption of some drugs when taken together in high amounts.
  • Not for: None at food levels

How it's used

In supplements

Not supplemented; exposure is dietary and incidental (also an excipient in tablets).

In skincare

0.5–2% as a thickener/stabilizer in gels and toothpaste.

Regulatory status

  • GRAS food additive; permitted in cosmetics and pharmaceuticals.
  • GRAS (generally recognized as safe) for food use.
  • INCI name on cosmetic labels: Cellulose Gum.
  • CIR-reviewed and found safe in cosmetics.

Popular products containing Cellulose Gum

  • Commercial ice creams and sauces — Standard stabilizerVarious · Food
  • Most toothpastes (e.g., Colgate Total) — Thickening and suspension agentColgate · Skincare
  • Bob's Red Mill Gluten-Free Flour Blends — Cellulose gum improves gluten-free textureBob's Red Mill · Food

Product names and brands are shown for reference and belong to their respective owners.

The gut-barrier studies

A 2015 Nature study fed mice CMC and polysorbate 80 at doses equivalent to many grams per day in humans — orders of magnitude above typical intake (tens to low hundreds of milligrams). The mice showed thinned mucus and gut inflammation. Follow-up human studies are small and inconsistent. The findings opened a legitimate research question about additive exposure in susceptible individuals, but they do not establish risk at dietary levels, and regulators worldwide have maintained approvals.

Fiber or additive?

Chemically, CMC is cellulose — dietary fiber — made water-soluble. It is not absorbed, and its calorie content is effectively zero. This dual identity explains its regulatory comfort: it is one of the few thickeners that is also a fiber.

Frequently asked questions

Is cellulose gum bad for your gut?

At food levels, the evidence says no. The concerning findings come from extreme-dose animal studies; human trials have not reproduced harm at realistic intakes.

Why is cellulose gum in toothpaste?

It thickens the paste and keeps abrasives and fluoride evenly suspended — without it, toothpaste would separate in the tube.

Is cellulose gum gluten-free?

Yes — it derives from wood/cotton cellulose, not grains, and is a standard tool in gluten-free baking.

The bottom line

Cellulose gum is a century-old, regulator-endorsed thickener with fiber properties — its gut-barrier controversy is preliminary science at extreme doses, not established risk.

References

  1. Dietary emulsifiers impact the mouse gut microbiota. Nature. https://pubmed.ncbi.nlm.nih.gov/25731162/
  2. Carboxymethylcellulose — JECFA evaluation. WHO/FAO Joint Expert Committee. https://www.fao.org/food-safety/scientific-advice/jecfa/en/
  3. Emulsifiers and intestinal health: where does the evidence stand?. PubMed Central. https://pubmed.ncbi.nlm.nih.gov/35347492/