To provide a microorganism having equol-producing ability and to provide a method for producing equol by using the microorganism and to provide foods and beverages, medicines and animal feed by using the microorganism.

The present invention provides do03 strain (AHU-1763) (FERM AP-20905) capable of being converted to equol by using daidzein as a substrate. The present invention further provides foods and beverages, supplements, medicines and feed in which the daidzein is previously converted to the equol by the do03 strain. The equol is a final effective substance of isoflavones and has good absorption into the intestinal tract. Prophylaxis of various kinds of diseases, e.g. breast cancer and prostatic cancer in which estrogen participates and progress-retarding action of these diseases can be expected by increasing the equol in foods.