Dietary rice bran promotes resistance to Salmonella enterica serovar Typhimurium colonization in mice
1 Department of Clinical Sciences, Colorado State University, Fort Collins, CO 80523, USA
2 Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO, 80523, USA
3 Department of Food Science and Human Nutrition, Colorado State University, Fort Collins, CO 80523, USA
4 Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO 80523, USA
BMC Microbiology 2012, 12:71 doi:10.1186/1471-2180-12-71Published: 14 May 2012
Dietary rice bran consists of many bioactive components with disease fighting properties; including the capacity to modulate the gut microbiota. Studies point to the important roles of the gut microbiota and the mucosal epithelium in the establishment of protection against enteric pathogens, such as Salmonella. The ability of rice bran to reduce the susceptibility of mice to a Salmonella infection has not been previously investigated. Therefore, we hypothesized that the incorporation of rice bran into the diet would inhibit the colonization of Salmonella in mice through the induction of protective mucosal responses.
Mice were fed diets containing 0%, 10% and 20% rice bran for one week prior to being orally infected with Salmonella enterica serovar Typhimurium. We found that mice consuming the 10 and 20% rice bran diets exhibited a reduction in Salmonella fecal shedding for up to nine days post-infection as compared to control diet fed animals (p < 0.05). In addition, we observed decreased concentrations of the pro-inflammatory cytokines, TNF-alpha, IFN-gamma, and IL-12 (p < 0.05) as well as increased colonization of native Lactobacillus spp. in rice bran fed mice (p < 0.05). Furthermore, in vitro experiments revealed the ability of rice bran extracts to reduce Salmonella entry into mouse small intestinal epithelial cells.
Increasing rice bran consumption represents a novel dietary means for reducing susceptibility to enteric infection with Salmonella and potentially via induction of native Lactobacillus spp.