Natto is a popular fermented soybean food in Japan since ancient times. It is considered to have a unique flavor, with a strong smell and sticky texture. If we look behind that unique taste, natto is rich in nutrients that may even surprise you. Natto has high vitamin K2 content, antibacterial action, and high dietary Natto is perhaps the healthiest soy product. That's because this fermented food provides beneficial probiotics along with supporting bone health, digestion and heart health. Nattō (納 なっ 豆 とう) is a traditional Japanese food made from whole soybeans that have been fermented with Bacillus subtilis var. natto. [1] It is often served as a breakfast food with rice. [2] It is served with karashi mustard, soy or tare sauce, and sometimes Japanese bunching onion. Within Japan, nattō is most popular in the eastern regions, including Kantō, Tōhoku, and Hokkaido. [3][4][5] Nattō is often considered an acquired taste because of its powerful smell, strong ... Natto is perhaps the healthiest soy product. That's because this fermented food provides beneficial probiotics along with supporting bone health, digestion and heart health.