Natto, a traditional Japanese food, is a nutritional powerhouse, rich in rare vitamins and antioxidants. The most notable nutrients are vitamin K2-MK7, pyrolloquinoline quinone (PQQ), and nattokinase.
In general, we do not recommend ingesting soy due to it's endocrine/nutrient-absorbtion disrupting and goitrogenic properties. Fermented soy is the exception to the rule. When soy is fermented, it disposes of these natural toxins, resulting in a healthy soy. Read more about healthy versus non-healthy soy HERE.