Boost your cardiovascular system with this remarkable supplement developed by the National Enzyme Company. Swanson Nattozimes are an all-natural enzyme supplement inspired by the popular Japanese health food, natto. For centuries, this product of boiled, fermented soybeans has been treasured by the Japanese as health promoting for the heart and circulation. Nattozimes, which are derived from two strains of fungi, can also benefit cardiovascular health. They promote healthy blood flow in the cardiovascular system.