Fermented whey dairy beverage offers protection against Salmonella enterica ssp. enterica serovar Typhimurium infection in mice

Fermented whey dairy beverages are dairy products obtained by fermentation from a mixture of milk and whey. These beverages have important health benefits, which could be improved with the addition of probiotic cultures. This study assessed the protective effect of the cosupplementation of a probiotic culture (Lactobacillus casei 01) with a fermented whey dairy beverage against infection by Salmonella enterica ssp. enterica serovar Typhimurium in a murine model. Two fermented whey dairy beverages were prepared: conventional (FWB; starter culture) and probiotic (PFWB; starter and probiotic cultures). In the first set of experiments, Balb/C female mice were treated with FWB or PFWB, challenged with Salmonella Typhimurium, and analyzed for clinical signs, weight loss, and mortality for 20 d postinfection. In the second set of experiments, mice were treated with FWB or PFWB, challenged with Salmonella Typhimurium, and killed on d 10 postinfection. The liver, colon, and ileum were used for myeloperoxidase, eosinophil peroxidase, and histological analysis and translocation to the liver. The contents from the small intestine were used for secretory IgA determination. The FWB treatment showed a better effect on animal survival (70%), translocation of the pathogen to the liver (2 out of 10), histopathology (fewer lesions), and inflammation than PFWB, which presented 50% animal survival, translocation in 5 out of 10 animals, and higher lesions. The control group presented 40% animal survival, translocation in 6 out of 10 animals, and severe lesions. Therefore, FWB was deemed to have a greater protective effect against Salmonella Typhimurium infection in the murine model compared with PFWB.