Provided is a fermented food containing an extract of at least one plant material selected from the group consisting of turmeric, Houttuynia cordata Thunb., Eucommia ulmoides Oliv., rice bran, persimmon leaves, perilla, clove, cinnamon and Rubus suavissimus S. Lee (Rosaceae) and bacteria of the genus Bifidobacterium. The fermented food contains an excellent and novel material with which the viability of the bacteria of the genus Bifidobacterium can be improved in storage of the product, and even when used in products such as beverages or foods, does not deteriorate the flavor of the product, thereby the bacteria of the genus Bifidobacterium can be contained at high concentration which provides various physiological effects.