Dietary Bifidobacterium lactis (HN019) enhances resistance to oral Salmonella typhimurium infection in mice

The ability of a newly identified probiotic lactic acid bacterial strain, B ifidobacterium lactis (HN019), to confer protection against Salmonella typh imurium was investigated in BALB/c mice. Feeding mice with B. lactis confer red a significant degree of protection against single or multiple oral chal lenge with virulent S. typhimurium, in comparison to control mice that did not receive B, lactis, Protection included a ten-fold increase in survival rate, significantly higher post-challenge food intake and weight gain, and reduced pathogen translocation to visceral tissues (spleen and liver), Furt hermore, the degree of pathogen translocation showed a significant inverse correlation with splenic lymphocyte proliferative responses to mitogens, bl ood and peritoneal cell phagocytic activity and intestinal mucosal anti-S. typhimurium antibody titers in infected mice; all of these immune parameter s were enhanced in mice fed B. lactis. Together, these results suggest that dietary B. lactis can provide a significant degree of protection against S almonella infection by enhancing various parameters of immune function that are relevant to the immunological control of salmonellosis. Thus dietary s upplementation with B. lactis provides a unique opportunity for developing immune-enhancing probiotic dairy food products with proven health benefits.