Cellulase
An enzyme that breaks down plant cell-wall cellulose, sold to reduce gas from vegetables. Humans do not digest cellulose anyway, and there are no trials of cellulase on its own in people.
Evidence last reviewed: August 2026
What the science says
- Gas and bloating from vegetables Limited evidence
No published human trial has tested cellulase alone for gas. The only human data come from multi-enzyme blends that happen to include cellulase; a randomised placebo-controlled trial of one such complex in functional dyspepsia reported less bloating, but the effect cannot be assigned to cellulase.
- A different enzyme has the actual evidence Moderate evidence
For gas from beans and cruciferous vegetables, the enzyme with randomised evidence is alpha-galactosidase, not cellulase. Placebo-controlled crossover trials found it reduced breath hydrogen and gas-related symptoms after an oligosaccharide-rich meal, though a later trial in irritable bowel syndrome found no symptom benefit.
- Digestive rationale Limited evidence
Cellulose passes through the human gut largely intact and is fermented by colonic bacteria rather than digested. A capsule of cellulase spends minutes in the stomach and small intestine, which is a poor match for where fibre fermentation actually happens.
Dosage & safety
Scientific references
- Evaluation of the Safety and Efficacy of a Multienzyme Complex in Patients with Functional Dyspepsia: A Randomized, Double-Blind, Placebo-Controlled Study
- The effect of oral alpha-galactosidase on intestinal gas production and gas-related symptoms
- Does oral α-galactosidase relieve irritable bowel symptoms?
Where to buy
Referral link — this site may earn a commission on purchases.
Related in Gut health
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- Ginger Moderate evidence
- Inulin (Prebiotic Fiber) Moderate evidence