There is little evidence for a relationship between probiotic metabolites and host cytokine production. We investigated in the present study the possibility that anti-inflammatory metabolites can be produced in the gut by LKM512 yogurt consumption by using murine macrophage-like J774.1 cells and extracts prepared from the feces of elderly volunteers. These volunteers' acute inflammation had been inhibited by LKM512 yogurt consumption in a previous test. The tumor necrosis factor (TNF)-alpha production elicited in J774.1 cells stimulated by lipopolysaccharide (LPS) and in the fecal extracts obtained during the period of LKM512 yogurt consumption was significantly decreased (p<0.05) than the pre-consumption baseline level. These findings and previous data enable us to conclude that intestinal bacterial metabolites produced by LKM512 yogurt consumption contributed to suppressing the inflammatory cytokine produced by macrophages and that one of the anti-inflammatory metabolites in the fecal extracts was likely to have been a polyamine.