The original type of sushi, known today as nare-zushi (馴れ寿司, 熟寿司,) was first made in Southeast Asia. Fish was salted and wrapped in fermented rice, a traditional lacto-fermented rice dish. Narezushi was made of this gutted fish which was stored in fermented rice for months at a time for preservation. The fermentation of the rice prevented the fish from spoiling. The fermented rice was discarded and fish was the only part consumed.This early type of sushi became an important source of protein for the Japanese.