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Lactoperoxidase (LPO Salivary Enzyme System)

Lactoperoxidase (LPO) — bovine + human salivary enzyme
Evidence Level
Moderate
3 Clinical Trials
7 Documented Benefits
3/5 Evidence Score

A salivary peroxidase enzyme: a heme glycopeptide of approximate mass ~78,000 Da (bovine) / ~80,000 Da (human) with a calcium-binding site (Asp227) and an autocatalytic heme B center. It oxidizes salivary thiocyanate (SCN-) in the presence of H2O2 to hypothiocyanite, a broad-spectrum antimicrobial. Human trials of high-dose lactoferrin + LPO tablets and of toothpaste using a three-enzyme system (amyloglucosidase + glucose oxidase + LPO) plus lactoferrin and lysozyme support gingivitis prevention, and a systematic review supports this use. Bovine LPO is structurally and functionally similar to human salivary LPO.

Studied Dose High-dose tablets: lactoferrin 60 mg + LPO 7.8 mg/day; low-dose: lactoferrin 20 mg + LPO 2.6 mg/day.
Active Compound Lactoperoxidase (LPO); bovine and human salivary enzyme. Single-chain monomeric glycopeptide ~78-80 kDa with autocatalytic heme B and Ca2+-binding site (Asp227).

Benefits

Gingival index reduction LF + LPO tablets

In a randomized double-blind placebo-controlled trial in healthy adults, high-dose tablets (lactoferrin 60 mg/d + LPO 7.8 mg/d) significantly reduced the Gingival Index vs placebo (P<0.05). Pivotal RCT supporting the gingivitis-prevention indication.

Supported by Trial 1

Toothpaste enzyme system gingivitis 13-week RCT

A double-blind randomized parallel-group home-use RCT in healthy non-smokers tested a toothpaste containing enzymes (amyloglucosidase + glucose oxidase + LPO) plus proteins (lactoferrin + lysozyme), reflecting natural saliva composition, vs a commercial control. The three-enzyme system reproduces the natural salivary defense mechanism rather than introducing exogenous antimicrobials.

Supported by Trial 2

Plaque and gingivitis in xerostomia

In patients with radiation-induced xerostomia, LPO toothpaste reduced the rate of supragingival plaque formation, and gingival inflammation was lower. Particularly relevant population, since xerostomia patients have impaired natural salivary defense and benefit from LPO supplementation. Small sample limits definitive conclusions.

Supported by Trial 3

Hypothiocyanite antimicrobial production (mechanism)

LPO oxidizes salivary thiocyanate (SCN⁻) using H₂O₂ as cofactor to generate hypothiocyanite (OSCN⁻) — a broad-spectrum antimicrobial active against both Gram-positive and Gram-negative pathogens. The natural salivary defense pathway, replicated by LPO supplementation.

Supported by Trial 2

Three-enzyme synergistic system

Amyloglucosidase + glucose oxidase generate H₂O₂ from glucose, which LPO then uses with thiocyanate to produce hypothiocyanite. Self-sustaining enzyme cascade — provides continuous low-level antimicrobial activity from dietary glucose substrate without exogenous H₂O₂ delivery.

Supported by Trial 2

Oral microbiome shift toward health (14-week)

Long-term use shifts the oral microbiome toward health-associated patterns including Neisseria spp. increases. Selective antimicrobial pressure favoring commensal over pathogenic species rather than blanket antibacterial action.

Supported by Trial 2

Systematic review (, 2024)

A systematic review found that toothpaste with amyloglucosidase + glucose oxidase + LPO + lysozyme + lactoferrin is effective for preventing gingivitis and managing gingival inflammation short-term and long-term, via reduced MGI, BI, and PI scores. Honest limitation acknowledged in the review: limited number of eligible studies.

Supported by Trial 2, Trial 3

Mechanism of action

1

Hypothiocyanite generation (LPO-SCN-H₂O₂ system)

The core LPO mechanism: oxidation of thiocyanate using H₂O₂ as cofactor to generate hypothiocyanite, a broad-spectrum antimicrobial. The natural salivary defense pathway.

2

Three-enzyme synergistic system

Amyloglucosidase + glucose oxidase cascade generates H₂O₂ from dietary glucose, which LPO uses to produce hypothiocyanite. Self-sustaining cascade providing continuous low-level antimicrobial activity.

3

Gram-positive and Gram-negative pathogen inhibition

Hypothiocyanite has broad-spectrum activity against periodontal pathogens including Streptococcus mutans, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans — covering the major Gram-positive and Gram-negative oral pathogens.

4

Heme B catalytic center + calcium binding

LPO contains an autocatalytic heme B center for the peroxidation reaction plus a calcium-binding site (Asp227) supporting structural stability. Standard heme peroxidase pharmacology with LPO-specific substrate preferences.

5

Oral microbiome shift toward health

Selective pressure favors commensal species (e.g., Neisseria spp. increase) over periodontal pathogens — rebalancing the oral microbiome toward health rather than blanket antibacterial action.

6

Salivary defense system reproduction

The natural human salivary LPO + thiocyanate + H₂O₂ system is enhanced by exogenous LPO supplementation — particularly valuable in xerostomia where natural saliva production is reduced. The intervention supplies what the body would normally produce.

Clinical trials

1
LF + LPO Tablets 150-Pt 12-Week Clinical Trial (pivotal)

Clinical evidence on Lactoperoxidase (LPO Salivary Enzyme System) for the indications and outcomes described.

healthy adults

Wakabayashi H et al. 2019. Randomized double-blind placebo-controlled trial in 150 healthy adults. High-dose tablets (lactoferrin 60 mg/d + LPO 7.8 mg/d) for 12 weeks significantly reduced Gingival Index vs placebo (P<0.05). Foundational systemic-tablet evidence for the gingivitis-prevention indication.

2
Enzyme/Protein Toothpaste Gingivitis 13-Week Clinical Trial

13-week double-blind randomized parallel-group home-use clinical trial in healthy non-smokers (mean MGI 2.00-2.75).

Clinical population described in trial publication.

13-week double-blind randomized parallel-group home-use clinical trial in healthy non-smokers (mean MGI 2.00-2.75). Toothpaste with three-enzyme system (amyloglucosidase + glucose oxidase + LPO) plus lactoferrin and lysozyme vs commercial control. Reproduces natural salivary defense composition rather than introducing exogenous antimicrobials.

3
Xerostomia 52-Day Crossover Trial

Single-blind crossover 52-day trial in 12 patients with radiation-induced xerostomia.

12 patients with radiation-induced xerostomia

Single-blind crossover 52-day trial in 12 patients with radiation-induced xerostomia. LPO toothpaste reduced rate of supragingival plaque formation; gingival inflammation was lower. Small sample size in a clinically important population (xerostomia patients).

Side effects and drug interactions

Common Potential side effects

Generally well-tolerated; topical/oral application of natural enzyme system.
Mild oral irritation (rare, transient).
Allergic reactions (rare; bovine-derived).
Pregnancy/lactation: limited specific data; toothpaste application generally considered safe.
Long-term safety: multiple multi-week toothpaste/tablet trials supportive.
Dry mouth (xerostomia): well-tolerated + beneficial population per PMID 8063434.
Bovine-derived ingredient sensitivities: caution.

Important Drug interactions

Topical/oral application — minimal systemic absorption.
Most medications: no documented interactions.
Fluoride toothpaste: compatible — typically formulated together.
Antibiotics (topical or systemic): theoretical complementary antimicrobial activity.
Mouthwash/oral antiseptics: avoid concurrent use within 30 minutes (potential enzyme inactivation).

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Frequently asked questions about Lactoperoxidase (LPO Salivary Enzyme System)

What is lactoperoxidase?

Lactoperoxidase is a natural enzyme found in milk, saliva, and other secretions that has antibacterial activity. It is part of the body's innate defense and is used in some oral-care products and as a natural preservative.

What is lactoperoxidase used for?

It is used mainly in oral-care products (toothpastes and mouthwashes for dry mouth) and as a natural antimicrobial system in foods, supporting a healthy balance of oral and gut bacteria.

How is lactoperoxidase taken?

It is most often delivered through oral-care products or specific formulas rather than as a standalone supplement; follow the specific product's directions.

Is lactoperoxidase safe?

It is a natural enzyme found in milk and saliva and is generally regarded as safe. Because it is typically dairy-derived, those with milk allergies should check product sourcing.

What is the recommended dosage of Lactoperoxidase?

The clinically studied dose is High-dose tablets: lactoferrin 60 mg + LPO 7.8 mg/day; low-dose: lactoferrin 20 mg + LPO 2.6 mg/day. Always follow the product label and check with a healthcare provider for personal advice.

Is Lactoperoxidase safe, and does it have side effects?

For most healthy adults, Lactoperoxidase is well tolerated at studied doses. Reported effects can include: Generally well-tolerated; topical/oral application of natural enzyme system. Mild oral irritation (rare, transient). It may also interact with some medications. Lactoperoxidase 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 Lactoperoxidase interact with any medications?

Possible interactions include: Topical/oral application — minimal systemic absorption. Most medications: no documented interactions. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Lactoperoxidase?

NutraSmarts rates the evidence for Lactoperoxidase as Moderate (3 out of 5). It is backed by 3 clinical trials and 4 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(4 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. Nakano M, Yoshida A, Wakabayashi H, Tanaka M, Yamauchi K, Abe F, Masuda Y Effect of tablets containing lactoferrin and lactoperoxidase on gingival health in adults: A randomized, double-blind, placebo-controlled clinical trial J Periodontal Res. 2019;54(6):702-708. doi: 10.1111/jre.12679.PubMedUsed to support: Human RCT (n=150) of tablets containing lactoperoxidase (LPO 7.8 mg/day) plus lactoferrin for 12 weeks, demonstrating gingival index reduction in adults — directly supporting the gingival index reduction LF+LPO tablets and digestive/immune benefits of lactoperoxidase.
  2. Hu X, Zhang P, Zhang L, Matheson JR, Lin S, Sun JN, Delfanti C, Tian J, Gupta AK, Vasantharaghavan R, Huang R The effect of enzyme and protein containing toothpaste on gingival condition: a randomised controlled study BMC Oral Health. 2025;25(1):1727. doi: 10.1186/s12903-025-07096-7.PubMedUsed to support: 26-week RCT in a Chinese population of a toothpaste containing lysozyme, lactoperoxidase, and lactoferrin vs. standard fluoride toothpaste, showing significant improvement in gingival health and plaque reduction — supporting three-enzyme synergistic system and toothpaste enzyme system gingivitis benefit for lactoperoxidase.
  3. van Steenberghe D, Van den Eynde E, Jacobs R, Quirynen M Effect of a lactoperoxidase containing toothpaste in radiation-induced xerostomia Int Dent J. 1994;44(2):133-138.PubMedUsed to support: Controlled human clinical study (n=12) of LPO-containing toothpaste in patients with radiation-induced xerostomia (dry mouth), assessing plaque, gingival inflammation, and subgingival microbiota — supporting plaque and gingivitis in xerostomia claim.
  4. Tenovuo J Clinical applications of antimicrobial host proteins lactoperoxidase, lysozyme and lactoferrin in xerostomia: efficacy and safety Oral Dis. 2002;8(1):23-29. doi: 10.1034/j.1601-0825.2002.1o781.x.PubMedUsed to support: Clinical review evaluating LPO, lysozyme, and lactoferrin incorporated into oral care products (dentifrices, mouthrinses, gels) to restore salivary antimicrobial capacity in xerostomia — supporting three-enzyme synergistic system, hypothiocyanite antimicrobial production mechanism, and clinical applications for plaque/gingivitis in dry mouth.