What Does Nattokinase Digest? Exploring the Fibrinolytic Enzyme

December 9, 2025 •

3 min read

Discovered in 1980 by Japanese researcher Dr. Hiroyuki Sumi, nattokinase is a potent enzyme derived from the traditional Japanese food natto. While it is a proteolytic enzyme capable of digesting proteins in general, its most significant action is the digestion of fibrin, a key component in blood clots.

Quick Summary

Nattokinase, a proteolytic enzyme from fermented soybeans, is best known for its potent ability to digest fibrin, the protein scaffold of blood clots. It also supports cardiovascular wellness through multiple mechanisms.

Key Points

Digests Fibrin: Nattokinase's primary and most potent digestive action is breaking down fibrin, the protein component of blood clots.
Enhances Circulation: By dissolving fibrin and reducing platelet aggregation, it helps improve blood flow and supports cardiovascular health.
Acts Systemically: Unlike digestive enzymes, nattokinase works throughout the bloodstream when taken between meals to target unwanted proteins.
Breaks Down Plaques: It contributes to reducing atherosclerotic plaque and lowering blood pressure, promoting overall heart health.
Lowers Coagulation Factors: The enzyme can also decrease levels of other clotting factors like Factor VII and VIII, enhancing its anticoagulant effects.
Potential Against Amyloids: Preliminary lab studies indicate an ability to degrade amyloid proteins associated with neurodegenerative diseases.
Anti-inflammatory Effects: It may help break down proteins involved in chronic inflammation, though more research is needed.

Understanding the Primary Target: Fibrin

Nattokinase's primary target is fibrin. Fibrin is a protein essential for blood clot formation to heal wounds, but its overaccumulation can lead to dangerous clots within the vascular system. Nattokinase breaks down the fibrin mesh, dissolving existing clots and preventing new ones. This makes it a potent antithrombotic and fibrinolytic agent.

The Direct and Indirect Mechanisms of Fibrin Digestion

Nattokinase digests fibrin through several pathways. As a serine protease, it uses a serine amino acid to cleave protein bonds. Its actions include:

Directly breaking down fibrin and plasmin substrates.
Activating plasminogen to produce plasmin, an enzyme that dissolves clots, and degrading plasminogen activator inhibitor (PAI-1).
Inhibiting platelet aggregation by blocking thromboxane formation, preventing new clots.

Impact on Cardiovascular Health

The digestion of fibrin by nattokinase supports cardiovascular health by improving blood flow and circulation. This can help lower high blood pressure and reduce atherosclerotic plaque formation. Improved circulation benefits the entire body.

Digestion of Other Proteins

Nattokinase is a proteolytic enzyme that can break down other proteins systemically, distinguishing it from general digestive enzymes. Taking it on an empty stomach allows it to enter the bloodstream and act on unwanted proteins.

Inflammatory Proteins: It may break down protein fragments contributing to inflammation.
Amyloid Proteins: Lab studies suggest nattokinase can degrade amyloid fibrils linked to neurodegenerative diseases, but more human research is needed.
Other Coagulation Factors: It can decrease levels of other clotting factors like factor VII and factor VIII, further supporting its anticoagulant properties.

Nattokinase vs. Digestive Enzymes: A Comparison


Feature	Nattokinase	Typical Digestive Enzymes (e.g., Papain, Bromelain)
Primary Function	Systemic proteolytic action, mainly targeting fibrin and other unwanted proteins in the bloodstream.	Breaking down macronutrients (proteins, fats, carbohydrates) in the digestive tract to aid nutrient absorption.
Optimal Timing	Between meals on an empty stomach to ensure it reaches the bloodstream and acts systemically.	With meals to help digest food.
Main Target	Fibrin, blood clots, atherosclerotic plaque, and other excess proteins in the body.	Dietary proteins, starches, and fats in the stomach and intestines.
Origin	Fermented soybeans using Bacillus subtilis natto.	Fruits (pineapple, papaya), plants, or animal sources.

Conclusion: The Broad Impact of Nattokinase's Digestion

Nattokinase primarily digests fibrin, supporting cardiovascular health by managing blood clotting, lowering blood pressure, and reducing arterial plaque. Its ability to digest other proteins, potentially related to inflammation and amyloid buildup, suggests broader systemic benefits requiring further human study. As a systemic enzyme, it differs from common digestive enzymes, acting to promote circulatory and cellular health when taken on an empty stomach. Consult a healthcare provider before use, especially if on blood-thinning medication.

Sources

For more detailed information on nattokinase's therapeutic effects, you can consult research articles on the National Institutes of Health website, such as this review on its cardiovascular applications: https://pmc.ncbi.nlm.nih.gov/articles/PMC6043915/.

The Power of Nattokinase: Key Takeaways

Digests Fibrin: Nattokinase primarily breaks down fibrin, the protein in blood clots.
Multi-action blood thinner: It dissolves clots and helps prevent new ones by inhibiting platelet aggregation and enhancing the body's natural fibrinolytic activity.
Circulatory health improved: It promotes better blood flow, potentially lowering blood pressure and reducing plaque buildup.
Systemic action required: For best systemic effects, take on an empty stomach.
Potential beyond blood clots: Preliminary studies suggest it may also digest proteins related to inflammation and amyloid accumulation.
Safe for most, but cautious for some: Consult a doctor if on anticoagulant medications or with bleeding disorders.

Frequently Asked Questions

While nattokinase is a proteolytic enzyme that breaks down proteins, it is primarily a systemic enzyme. For effects like fibrin breakdown in the bloodstream, it's best taken on an empty stomach.

Nattokinase primarily breaks down fibrin, the protein that forms blood clots.

Yes, nattokinase is known for its ability to digest blood clots by directly degrading fibrin and increasing plasmin production.

Studies suggest nattokinase may help lower blood pressure by improving blood flow and acting as an ACE inhibitor.

Generally safe, nattokinase's blood-thinning effect can increase the risk of bruising and bleeding, especially with other anticoagulants.

Avoid or use cautiously if taking blood thinners, have bleeding disorders, are pregnant or breastfeeding, or have surgery scheduled.

For systemic effects, take nattokinase on an empty stomach between meals.

Lab studies show it can degrade amyloid fibrils, but human trials are needed.

Clinical studies suggest it can reduce plaque size and slow atherosclerosis progression.