Lactobacillus reuteri protects mice against Salmonella typhimurium challenge by activating macrophages to produce nitric oxide.

Lactobacillus reuteri, a typical intestinal symbiotic bacterium, plays an important role in maintaining intestinal flora stability and host health. However, the effect of Lactobacillus reuteri on peritoneal macrophages has not been thoroughly studied. Our study indicated that Lactobacillus reuteri could activate macrophages and that macrophages treated with Lactobacillus reuteri have an enhanced ability to phagocytose and to kill intracellular Salmonella typhimurium. Lactobacillus reuteri may reduce the inflammatory response caused by Salmonella typhimurium by regulating NO, thus effectively protecting mice against Salmonella typhimurium invasion and dissemination to the liver and spleen. Taken together, these data demonstrated the protective effect of Lactobacillus reuteri on macrophages and mice challenged with Salmonella typhimurium through in vitro and in vivo experiments.