IL-12 is known to be one of the cytokines that causes an immunity balance shift to the Th 1 side. It was examined whether products from a Japanese sake-brewing process influence the production of IL-12 p40. When the extracts of the products were added to the assay system, the production of IL-12 p40 by the mouse macrophages (J 774.1) was promoted. The production of IL-12 p40 was stimulated not only by the addition of the alkaline extract from the moromi mash in the sake-brewing process but also the extracts from Japanese sake and sake cake.