In the present study, we found that oral administration of HDB1258, a novel probiotic isolated from healthy infant feces, significantly induced splenic NK cell cytotoxicity against YAC-1 tumor cells, peritoneal macrophage phagocytosis against Candida albicans, TNF-α to IL-10 expression ratio in the spleen, and TNF-α, IL-1β, and IL-6 expression in the colon,. The gene discussed is IL10; the disease is neoplasm.