“…It has been eaten in Japan for approximately 1,000 years and is known as a functional food. Natto is a probiotic (Hosoi & Kiuchi, 2008;Sanders, Morelli, & Tompkins, 2003), and abundantly contains nattokinase (Sumi et al, 1987), vitamin K2 (menaquinone) (Kaneki et al, 2001;MEXT, 2015), poly-γ-glutamic acid (Fujii, 1963), isoflavones (Esaki et al, 1990;Shimakage et al, 2006), etc. Nattokinase is a fibrinolytic enzyme whose thrombolytic activity is stronger than plasmin (Fujita et al, 1995), and alsopossess antioxidant effects (Iwai et al, 2002a;Iwai et al, 2002b), estrogenic activity (Santell et al, 1997), antitumor effects (Ravindranath et al, 2004), and preventive effects on bone loss (Toda et al, 1999).…”