The present invention is directed to a composition for use in liver function improvement, blood alcohol level reduction and in-vivo antioxidant activity enhancement, 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, vitamin B.sub.1, B.sub.2, B.sub.3, B.sub.6, B.sub.9, B.sub.12, C, and E. The composition can improve declined liver functions and shows excellent hepatoprotective and hepatocurative activity against alcohol on excessive or habitual drinking with the ability to reduce blood alcohol levels. Its superior enhancement of in-vivo antioxidant activity also contributes to the use of the composition in the prevention of liver diseases and the improvement of liver functions. Also disclosed are fermented dairy foods, beverages, and health foods, containing the composition as an effective component.