Health conscious Japanese eat a popular breakfast food called natto, which is a fermented soybean product. Consumption of natto may be part of the reason for the low rates of heart disease found in Japan. Natto is rich in an enzyme known as nattokinase, which is useful at preventing blood clots. Nattokinase can also be made in the laboratory from boiled soybeans and special bacteria called Bacillus subtilis natto. Research has shown that nattokinase can support healthy coagulation of blood and enhance the body's ability to break down blood clots. By taking nattokinase you may experience improvements in heart health, energy, mental function and circulation. We often recommend nattokinase for people at risk of blood clots. This includes people who have either had blood clots or have a strong family history of clots. Also, people who have done genomics testing and have two copies of mutated PAI-1 gene may want to take nattokinase to reduce their risk as well. For health maintenance, we recommend one capsule of natto-serrazime twice a day.