Nattokinase is a potent proteolytic enzyme extracted from natto, a traditional Japanese food made by fermenting soybeans with the bacterium Bacillus subtilis natto. This enzyme is widely recognized for its fibrinolytic activity, meaning it helps to break down fibrin, a protein involved in blood clot formation. The supplement is primarily sought after for supporting cardiovascular and circulatory health. While generally considered safe, Nattokinase can occasionally trigger unwanted reactions within the digestive system.
Nattokinase and the Risk of Diarrhea
The direct answer is that Nattokinase can cause diarrhea; it is a reported, though uncommon, side effect associated with its use. Most clinical data suggest the enzyme has a low incidence of adverse effects when consumed at standard dosages. Mild gastrointestinal disturbances, such as stomach discomfort or nausea, are the most frequently noted digestive complaints.
Diarrhea represents a more significant form of gastrointestinal upset, particularly when initiating supplementation or using higher doses. The safety profile of the enzyme is strong, with studies indicating it is safe for consumption over long periods, sometimes up to three years. However, even mild symptoms of digestive distress can be disruptive. The overall consensus remains that severe side effects are rare, but individual sensitivity plays a large role in determining tolerance.
Factors Contributing to Digestive Upset
The biological activity of Nattokinase itself is the primary reason it can lead to digestive irritation. As a serine protease, the enzyme’s fundamental function is to break down proteins. When this highly active enzyme reaches the gastrointestinal tract, its potent proteolytic action can irritate the delicate mucosal lining of the intestines. This irritation can disrupt the normal movement of the bowel, leading to increased fluid secretion and diarrhea.
The enzyme’s interaction with the complex environment of the gut microbiome may also contribute to the issue. The introduction of any new bioactive component can temporarily shift the balance of gut bacteria. This shift can result in digestive symptoms like gas, bloating, and loose stools. Sensitivity to soy proteins, even in the purified form of the enzyme, may also be a factor for some users.
Beyond the enzyme’s intrinsic activity, the manufacturing and formulation of the supplement can also play a part. Different brands use various inactive ingredients, fillers, or capsules to deliver the enzyme. These non-active components, such as binders or flow agents, may be poorly tolerated by sensitive individuals and can independently cause digestive distress. Scrutinizing the complete ingredient list is important when trying to identify the source of a reaction.
Practical Steps for Managing Symptoms
If digestive symptoms like diarrhea occur after starting Nattokinase, a practical first step is to modify the intake schedule. Reducing the daily dosage temporarily may allow the digestive system to adapt to the new enzyme, often resolving mild symptoms. Once discomfort subsides, the dose can be gradually increased back to the desired level.
Another effective strategy is adjusting the timing of your supplement intake. Taking Nattokinase with a light meal can help to buffer the enzyme’s proteolytic activity by directing it toward the food proteins rather than the intestinal lining. This may reduce the potential for irritation and subsequent digestive upset.
Maintaining adequate hydration is important, especially if diarrhea persists, as the condition can quickly lead to fluid and electrolyte loss. Increased intake of clear fluids or electrolyte-rich beverages is necessary to counteract this effect. If symptoms are severe, persistent, or accompanied by fever, blood in the stool, or intense abdominal pain, discontinue the supplement immediately and consult a healthcare professional.