Physiological Interactions of Salmonella and the intestinal microbiota

Protection against bacterial pathogens is one of the most important symbiotic functions that the diverse intestinal microbiota confers to its host. Efficient nutrient competition of the many indigenous microorganisms is an ecological foundation of this protective effect. In return, disturbances in intestinal ecology, such as by antibiotic therapy, lead to vacant nutritional niches that provide colonization opportunities for foodborne pathogens, which subsequently cause inflammation to even further leverage the altered nutrient availability in the gut. Substrate use and partitioning among the different microbiota members and incoming pathogens is thus fundamental to microbial niche segregation in the intestinal ecosystem, but still insufficiently understood. This joint project aims to provide a detailed understanding of the physiological interactions between individual microbiota members and the foodborne pathogen Salmonella, and to identify protective microorganisms. Findings from this research will contribute to future therapies by defining microbial metabolic properties and physiological conditions that prevent colonization or promote clearance of the pathogen.

Protection against bacterial pathogens is one of the most important symbiotic functions that the diverse intestinal microbiota confers to its host. Efficient nutrient competition of the many indigenous microorganisms is an ecological foundation of this protective effect. In return, disturbances in intestinal ecology, such as by antibiotic therapy, lead to vacant nutritional niches that provide colonization opportunities for foodborne pathogens, which subsequently cause inflammation to even further leverage the altered nutrient availability in the gut. Substrate use and partitioning among the different microbiota members and incoming pathogens is thus fundamental to microbial niche segregation in the intestinal ecosystem, but still insufficiently understood. This joint project contributed to a more detailed understanding of the physiological interactions between individual microbiota members and the foodborne pathogen Salmonella. Project highlights include the identification of Salmonella-antagonizing microorganisms, insights into their protective mechanisms, and discovery of a selective nutrient and potential prebiotic for human gut commensals.