Natto is a common food that can be eaten in moderation to supplement protein and other nutrients, but has no medicinal effects, and is commonly eaten in the form of natto rice. Natto, which originated in China during the Qin and Han Dynasties and was later introduced to Japan, is a soybean product made by fermenting soybeans with the bacterium Bacillus subtilis. The main nutrient in natto is protein, which accounts for 19.4%. The most abundant mineral in natto is potassium, with a specific content of 729mg/100g, which ranks high among similar foods. The phytochemical that is high in natto is flavonoids, with a specific content of 82.28mg/100g. Natto is commonly consumed by mixing it with soy sauce or Japanese mustard until it appears shredded, and serving it on top of rice, called natto rice, or by mixing it with granulated sugar, among other ways of consumption. Moderate consumption of natto can replenish some of the nutrients needed by the human body, but the nutrients needed by the human body are too diverse to be fully provided by natto consumption alone, and patients are advised to eat a balanced diet. There is no research that shows that natto has medicinal properties and effects, so it is recommended that patients go to a regular hospital in case of discomfort and follow the doctor’s instructions for symptomatic treatment. Natto should not be consumed by those who are allergic to soybeans.