A fermented dairy food, containing as an effective component a composition for liver function improvement, blood alcohol level reduction and in-vivo antioxidant activity enhancement, said composition comprising Lactobacillus brevis HY7401, Lactobacillus fermentum CS332, Lactobacillus acidophilus CSG, Bifidobacterium longum HY8001, an Alder tree extract, a Selfheal extract, a milk thistle extract, a green bean-rice bran fermentation extract, a turnip extract, a tomato extract, a broccoli extract, a pineapple extract, a colostrum powder, betaine, and vitamins B1, B2, B3, B6, B9, B12, C, and E.