Hemicellulase (Plant Fiber Digestive Enzyme)

Not a species name: hemicellulase is a group of enzyme activities that target plant hemicelluloses
Evidence Level
Preliminary
3 Clinical Trials
4 Documented Benefits
1/5 Evidence Score

Hemicellulase is a digestive enzyme that breaks down hemicellulose, a type of fiber found in plant cell walls. Because humans do not produce it, hemicellulase is added to digestive-enzyme blends with the aim of breaking down fibrous plant foods before they reach the colon. No published study has given hemicellulase on its own to people and measured anything: the human data are an uncontrolled case series of a seven-enzyme capsule and trials of multi-enzyme mixtures in which hemicellulase is one ingredient among many, and the rest of the research is in culture dishes and farm animals. It is taken with meals, especially fibrous, plant-heavy ones, as part of an enzyme formula rather than alone. Hemicellulase is generally well tolerated; as with any enzyme product, those with enzyme allergies or digestive conditions should check with a doctor before use.

Studied Dose No studied dose; labels list about 200 to 2,000 HCU per serving. Health Canada caps it at 45,000 FCC HCU per day.
Active Compound A group of enzyme activities (xylanase, mannanase, arabinanase and related specificities) produced by fermenting Aspergillus flavus var. oryzae, Aspergillus niger, Trichoderma longibrachiatum or Trichoderma reesei; sold by activity in HCU rather than by weight.

Benefits

One ingredient in multi-enzyme blends, never tested on its own

Hemicellulase appears in plant-based multi-enzyme formulations alongside cellulase, amylase, glucoamylase, lactase, protease, and lipase. The 82.5% figure often quoted for this enzyme comes from a narrative review by Graham and colleagues, which describes a retrospective series reported by Money and co-workers: 104 patients seen over ten years for irritable bowel syndrome-like symptoms, of whom 86 had follow-up, and 71 (82.5%) reported improvement or elimination of symptoms while taking an over-the-counter capsule, Essential Enzymes 500, before meals. There was no control group, no randomization and no placebo. The capsule contained acid-stable protease, lipase, alpha-amylase, amyloglucosidase, cellulase, hemicellulase and lactase, seven enzymes that were never separated, so no part of that number belongs to hemicellulase.

Hydrolysis of plant cell wall polysaccharides

Hemicellulase hydrolyzes hemicelluloses (xylans, glucans, galactans, mannans and pentosans) into simpler sugars. That reaction is well characterized in the laboratory; how much of it happens in the human upper gut after a capsule has never been measured. Fiber-rich breakfast cereals contain 2-12% hemicellulose. Humans lack endogenous hemicellulase activity and rely on colonic bacteria for any hemicellulose breakdown.

Pre-fermentation reduction of gas substrate: a mechanism, not a measured effect

Mechanistically, partial pre-digestion of plant fibers in the upper GI before they reach colonic fermentation would reduce the substrate available to gas-producing bacteria. That is a plausible idea for FODMAP-sensitive or gas-prone people on plant-rich diets, and it is the honest reason the enzyme is put into blends. It is untested rather than sparsely tested: hemicellulase has never been given on its own in a published trial, and the multi-enzyme studies that did measure gas and bloating cannot say which of their several enzymes, if any, produced the change.

Sourcing note: fungal, not animal derived (not a health effect)

This is a sourcing property rather than a health effect. Commercial hemicellulase is produced by fermenting Aspergillus niger, Aspergillus oryzae, Trichoderma reesei or Trichoderma longibrachiatum, so it suits vegan, vegetarian and kosher formulations. There is no animal-derived hemicellulase on the market. Note that a product containing hemicellulase can still contain animal-derived ingredients, so check the whole label.

Mechanism of action

1

Hydrolysis of hemicellulose polysaccharides

The enzyme group hydrolyzes β-1,4 glycosidic bonds in xylans, glucans, galactans, mannans, and pentosans, releasing simpler sugars and partially digested fragments that human enzymes can further process or that are more readily absorbed.

2

Local GI lumen activity, no systemic absorption

Hemicellulase acts in the gut lumen and is not absorbed into the bloodstream. Like any dietary protein it is broken down by stomach acid and by pancreatic proteases, which keeps the safety profile favorable but also limits how long it can act on a meal. Fungal enzymes are generally more acid-tolerant than pancreatic enzymes, which is one reason fungal sources are used in supplements, but no study has measured how much hemicellulase activity survives a real human stomach.

3

Plant cell wall degradation releases trapped nutrients

Plant cell walls contain hemicellulose, cellulose, and lignin. Partial hemicellulose breakdown improves access of digestive enzymes to nutrients otherwise trapped within the cell wall matrix, theoretically improving bioavailability from plant foods, though this has been measured mainly in animal feed studies.

4

Biofilm matrix disruption: one test tube study, nothing in people

One laboratory study grew biofilms in culture plates and treated them with a commercial blend containing cellulase and hemicellulase alongside lysozyme, serratiopeptidase, beta-glucanase, lipase, protease, N-acetyl cysteine and cranberry, berberine, rosemary and peppermint extracts, reporting less biofilm mass and metabolic activity for Candida albicans and two Staphylococcus species. Nothing was tested in a person, the study was funded by the company that sells the blend, and hemicellulase was never tested on its own.

Clinical trials

1
Uncontrolled Retrospective Case Series Described in a Review: Seven-Enzyme Capsule, No Placebo
PubMed

A narrative review by Graham and colleagues describes a retrospective series reported by Money and co-workers: 104 patients seen over ten years for irritable bowel syndrome-like symptoms, of whom 86 had follow-up, and 71 (82.5%) reported improvement or elimination of symptoms while taking an over-the-counter capsule, Essential Enzymes 500, containing acid-stable protease, lipase, alpha-amylase, amyloglucosidase, cellulase, hemicellulase and lactase before meals.

Clinical population described in trial publication.

A narrative review by Graham and colleagues describes a retrospective series reported by Money and co-workers: 104 patients seen over ten years for irritable bowel syndrome-like symptoms, of whom 86 had follow-up, and 71 (82.5%) reported improvement or elimination of symptoms while taking an over-the-counter capsule, Essential Enzymes 500, containing acid-stable protease, lipase, alpha-amylase, amyloglucosidase, cellulase, hemicellulase and lactase before meals. There was no control group, no randomization and no placebo, so an 82.5% response rate collected this way cannot be compared with anything and cannot be separated from natural fluctuation, diet change or expectation. Seven enzymes were taken together and none of the result belongs to hemicellulase specifically.

2
Test Tube Study Only: Enzyme and Botanical Blend Against Biofilms Grown in Culture
PubMed

An in vitro study treated biofilms grown in culture plates with a manufacturer-funded blend containing cellulase and hemicellulase plus lysozyme, serratiopeptidase, beta-glucanase, lipase, protease, N-acetyl cysteine, cranberry, berberine, rosemary and peppermint, and reported reduced biofilm mass and metabolic activity for Candida albicans, Staphylococcus aureus and Staphylococcus simulans.

Clinical population described in trial publication.

An in vitro study treated biofilms grown in culture plates with a manufacturer-funded blend containing cellulase and hemicellulase plus lysozyme, serratiopeptidase, beta-glucanase, lipase, protease, N-acetyl cysteine, cranberry, berberine, rosemary and peppermint, and reported reduced biofilm mass and metabolic activity for Candida albicans, Staphylococcus aureus and Staphylococcus simulans. In that paper it is beta-glucanase that is credited with targeting fungal beta-glucans, while cellulase and hemicellulase are credited with targeting bacterial cellulose. Results were mixed elsewhere: Borrelia burgdorferi biofilm mass fell but residual metabolic activity rose, and higher doses of the blend increased Pseudomonas aeruginosa biofilm mass. No person took part, and nothing here shows what hemicellulase does in a human gut.

3
Animal Feed Research Only: Poultry and Pigs, Not People
PubMed

Adding hemicellulases and related carbohydrate-active enzymes to the feed of monogastric farm animals improves the nutritional value of cereal and protein-meal diets and improves growth performance. This is well established in animal nutrition and was reviewed by Plouhinec and colleagues in 2023.

Clinical population described in trial publication.

Adding hemicellulases and related carbohydrate-active enzymes to the feed of monogastric farm animals improves the nutritional value of cereal and protein-meal diets and improves growth performance. This is well established in animal nutrition and was reviewed by Plouhinec and colleagues in 2023. These are farm animals on cereal and co-product diets nothing like a human meal, and the outcome measured is growth and feed conversion, not comfort after eating. None of it has been shown to carry across to human digestive symptoms.

Side effects and drug interactions

Common Potential side effects

Generally well-tolerated; food-grade enzyme of fungal origin.
Mild GI upset, and more gas or bloating when first starting, which usually settles and which runs opposite to the mechanism claimed for the enzyme.
Diarrhea or loose stools in some users (overuse).
Allergy: fungal hemicellulase and xylanase are established occupational respiratory sensitizers. Of 135 bakery worker blood samples, 8 (6%) carried IgE to a cellulase, hemicellulase and xylanase mixture, and workers sensitized to bakery enzymes reported more nasal symptoms than workers sensitized to wheat flour alone. That risk comes from breathing enzyme dust at work, not from swallowing a capsule: when bread baked with fungal alpha-amylase and hemicellulase was eaten by 17 adults with positive skin prick tests to Aspergillus fumigatus in a randomized crossover test, there was no increase in respiratory or other symptoms and no change in lung function or bronchial hyperreactivity. Stop use if any allergic reaction occurs, and do not open capsules and inhale the powder.
Pregnancy/lactation: limited specific data.
Long-term safety: limited human supplementation data.

Important Drug interactions

Most medications: no documented interactions.
Other digestive enzymes: compatible (often combined).
Diabetes: Health Canada requires products containing carbohydrate-digesting enzymes to carry the statement 'ask a health care practitioner before use if you have diabetes', on the reasoning that releasing more sugar from a meal could change post-meal glucose. No interaction study has been done in people taking diabetes medication.
Anticoagulants: no documented interactions.
Antibiotics: no documented interactions.

Frequently asked questions about Hemicellulase (Plant Fiber Digestive Enzyme)

What is hemicellulase?

Hemicellulase is an enzyme that breaks down hemicellulose, a type of plant fiber in cell walls. Like cellulase, it is included in digestive-enzyme blends to help break down fibrous plant foods, since humans do not make it.

What is hemicellulase used for?

It is put into digestive-enzyme formulas to break down plant fiber, on the reasoning that fiber broken down higher up the gut feeds fewer gas-producing bacteria in the colon. That reasoning has not been tested in people: hemicellulase has never been given on its own in a published trial. Health Canada licenses it only as a digestive enzyme or digestive aid, with no permitted claim about gas or bloating, unlike alpha-galactosidase, which does carry a flatulence claim.

When should I take hemicellulase?

Enzyme blends are labelled to be taken with a meal, and with fibrous plant-heavy meals if you are taking one for that reason. Whether hemicellulase actually acts on the meal in a human stomach has not been measured.

Is hemicellulase safe?

It is generally well tolerated, and in the one published test where people actually swallowed it, in bread, there were no reactions even in adults sensitized to Aspergillus. Health Canada allows up to 45,000 FCC HCU a day. People with diabetes, and anyone pregnant or breastfeeding, should ask a health professional first, and anyone should stop if an allergic reaction occurs.

What is the recommended dosage of Hemicellulase?

The clinically studied dose is No studied dose; labels list about 200 to 2,000 HCU per serving. Health Canada caps it at 45,000 FCC HCU per day. Always follow the product label and check with a healthcare provider for personal advice.

Is Hemicellulase safe, and does it have side effects?

For most healthy adults, Hemicellulase is well tolerated at studied doses. Reported effects can include: Generally well-tolerated; food-grade enzyme of fungal origin. Mild GI upset, and more gas or bloating when first starting, which usually settles and which runs opposite to the mechanism claimed for the enzyme. It may also interact with some medications. Hemicellulase is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does Hemicellulase interact with any medications?

Possible interactions include: Most medications: no documented interactions. Other digestive enzymes: compatible (often combined). If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Hemicellulase?

NutraSmarts rates the evidence for Hemicellulase as Preliminary (1 out of 5). It is backed by 3 clinical trials and 6 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(6 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Ullah H, Di Minno A, Piccinocchi R, Buccato DG, De Lellis LF, Baldi A, El-Seedi HR, Khalifa SA, Piccinocchi G, Xiao X, Sacchi R, Daglia M Efficacy of digestive enzyme supplementation in functional dyspepsia: A monocentric, randomized, double-blind, placebo-controlled, clinical trial Biomed Pharmacother. 2023;169:115858. doi:10.1016/j.biopha.2023.115858.PubMedUsed to support: Randomized, double-blind, placebo-controlled trial in 120 adults aged 18 to 59 with functional dyspepsia. Two capsules a day of a multi-enzyme blend from fungal fermentation (200 mg of blend per capsule) for two months improved Nepean Dyspepsia Index quality-of-life scores, pain on a visual analogue scale and Pittsburgh Sleep Quality Index sleep scores compared with placebo, with no side effects reported. The tested product was a mixture of enzymes and it is not established that hemicellulase was one of them, so nothing in the result can be attributed to hemicellulase.
  2. Graham DY, Ketwaroo GA, Money ME, Opekun AR Enzyme therapy for functional bowel disease-like post-prandial distress J Dig Dis. 2018;19(11):650-656. doi:10.1111/1751-2980.12655.PubMedUsed to support: Narrative review of about 60 years of studies of multi-enzyme digestive preparations for post-meal symptoms resembling irritable bowel syndrome. The authors report that these studies have generally been positive but state that none used a factorial design and none attempted to link a specific symptom response to a specific component of therapy, so the review cannot show what any individual enzyme contributed. Two of the studies it describes used hemicellulase-containing products: a 1960 placebo-controlled trial of a digestive aid combining pancreatic enzymes, bile salts, betaine hydrochloride and hemicellulase, in which 16 of 22 treated patients (73%) reported good to excellent symptom relief against 1 of 10 on placebo while fecal fat and fecal nitrogen were unchanged, and an uncontrolled retrospective series in which 71 of 86 patients (82.5%) taking a seven-enzyme over-the-counter capsule reported improvement.
  3. Cullinan P, Cook A, Jones M, Cannon J, Fitzgerald B, Taylor AJ Clinical responses to ingested fungal alpha-amylase and hemicellulase in persons sensitized to Aspergillus fumigatus? Allergy. 1997;52(3):346-9. doi:10.1111/j.1398-9995.1997.tb01003.x.PubMedUsed to support: Randomized crossover challenge in 17 adults with positive skin prick tests to Aspergillus fumigatus. Bread baked with fungal alpha-amylase and hemicellulase produced no increase in respiratory or other symptoms, no change in lung function and no change in non-specific bronchial hyperreactivity compared with bread baked without the enzymes. This is a small tolerability result about swallowing the enzyme, not evidence that hemicellulase aids digestion.
  4. Elms J, Fishwick D, Walker J, Rawbone R, Jeffrey P, Griffin P, Gibson M, Curran AD Prevalence of sensitisation to cellulase and xylanase in bakery workers Occup Environ Med. 2003;60(10):802-4. doi:10.1136/oem.60.10.802.PubMedUsed to support: Of 135 bakery worker serum samples, 8 (6%) carried specific IgE to a mixture of cellulase, hemicellulase and xylanase and 16 (12%) to fungal alpha-amylase. Workers sensitized to these bakery enzymes reported significantly more nasal symptoms than workers sensitized to wheat flour alone. This describes inhaled occupational exposure to enzyme dust in a bakery, not swallowing an enzyme capsule.
  5. Jensen GS, Cruickshank D, Hamilton DE Disruption of Established Bacterial and Fungal Biofilms by a Blend of Enzymes and Botanical Extracts J Microbiol Biotechnol. 2023;33(6):715-723. doi:10.4014/jmb.2212.12010.PubMedUsed to support: In vitro study. Biofilms of Candida albicans, Staphylococcus aureus, Staphylococcus simulans, Borrelia burgdorferi and Pseudomonas aeruginosa were grown in culture and treated with a blend containing cellulase and hemicellulase alongside lysozyme, serratiopeptidase, beta-glucanase, lipase, protease, N-acetyl cysteine and cranberry, berberine, rosemary and peppermint extracts. Biofilm mass and metabolic activity fell for Candida and both Staphylococcus species, while higher doses of the blend increased Pseudomonas biofilm mass. No people were involved and the study was funded by the company that sells the blend.
  6. Plouhinec L, Neugnot V, Lafond M, Berrin JG Carbohydrate-active enzymes in animal feed Biotechnol Adv. 2023;65:108145. doi:10.1016/j.biotechadv.2023.108145.PubMedUsed to support: Review of cellulases, hemicellulases and pectinases added to the feed of monogastric farm animals, describing improved nutritional value of cereal and protein-meal diets and improved performance and health in poultry and pigs. Two of its four authors work for a feed-enzyme manufacturer and the review discusses that company's own commercial enzyme cocktail. This is agricultural evidence in livestock, not evidence in people.