Natto benefitsThe consumption of natto is linked to longlivety, improved gut health, cholesterol reduction, anti-cancer, stronger bones and healthier brains. Natto contains unique compounds such as nattokinase and vitamin K2. Most of the potent health effects are coming from the fermentation process by Bacillus subtilus var natto (also called Bacillus natto). This fermentation process also improves the digestibility of soy and increases nutrient absorption.
ProbioticsNatto contains billions of living Bacillus natto bacteria that play a role in improving gut health. Bacillus natto bacteria help to fight against pathogens such as E. coli and salmonella. Before the introduction of antibiotics cultures of Bacillus subtilus were used to treat dysentery and other intestinal problems.
LonglivetyJapanese consume about billions of packets of natto each year and enjoy long lives, about 5 years longer than Americans.
Stronger bonesVitamin K2 is not found in plants but is only produced by certain bacteria, such as Bacillus natto. This vitamin helps to deposit the calcium in our bones. Vitamin K acts on osteoblasts, bone cells that deposit calcium in our bones. One study found that women who ate more than 160 grams of natto per week showed reduced bone mass loss .
Heart healthNatto improves the blood circulation by breaking up clots and preventing them from forming. The unique enzymes that play an important role are nattokinase and pyrazine. Nattokinase is concentrated in the typical natto strings and acts as a clot busting enzyme. Studies suggest that it helps to remove calcium from the arteries. Eating natto can benefit people with high cholesterol or triglyceride levels . Eating 30 g of natto daily during one month reduced cholesterol by 8% in patients with high cholesterol and reduced triglycerides by almost 13% in those with high triglycerides.
References Intake of fermented soybeans, natto, is associated with reduced bone loss in postmenopausal women: Japanese Population-Based Osteoporosis (JPOS) Study. Journal of Nutrition, 2006 May;136(5):1323-8.
 Vitamin K2 (menatetrenone) effectively prevents fractures and sustains lumbar bone mineral density in osteoporosis. Journal of Bone and Mineral Research, 2000 Mar;15(3):515-21.
 Japanese fermented soybean food as the major determinant of the large geographic difference in circulating levels of vitamin K2: possible implications for hip-fracture risk. Journal of Nutrition. 2001 Apr;17(4):315-21.
 Association between vitamin K intake from fermented soybeans, natto, and bone mineral density in elderly Japanese men: the Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) study. Osteoporos Int. 2012 Feb;23(2):705-14.
 Examining the Effects of Natto (fermented soybean) Consumption on Lifestyle-Related Diseases. International Conference on Nutrigenomics & Gut Health in New Zealand. April 30- May 3, 2006.