Consumption of Bifidobacterium lactis LKM512 yogurt reduces gut mutagenicity by increasing gut polyamine contents in healthy adult subjects

The possible role of probiotic metabolites on human health effects of probiotics has received little research attention. In this study, we investigated the effects of consumption of Bifidobacterium lactis LKM512-containing yogurt (LKM512 yogurt) on fecal probiotic metabolites (polyamines, lactate, and acetate) and mutagenicity in seven healthy adults (one male and six females; average age: 30.5 years). Each volunteer was provided with 100 g/day of LKM512 yogurt or placebo for 2 weeks. Fecal polyamines and mutagenicity were measured by HPLC and the umu-test, respectively. Consumption of LKM512 yogurt increased fecal spermidine levels, but not fecal lactate and acetate contents. The mutagenicity level significantly reduced to 79.2% (10-91.1%) and 47.9% (0-86.8%) following consumption of LKM512 yogurt (P = 0.0293) and placebo (P = 0.0314), respectively. LKM512 yogurt consumption significantly reduced the mutagenicity level compared with consumption of a placebo (P = 0.0489). These results suggest that increased gut spermidine level by LKM512 yogurt was responsible for the reduction of mutagenicity in the gut of healthy adults. We suggest that spermidine produced by LKM512 yogurt consumption contributes to host health as a bioantimutagenic factor; to our knowledge, these substances have not been previously reported as antimutagens from probiotics or fermented milk. (C) 2004 Elsevier B.V. All rights reserved.