The abundance of ethanolamine (EA) and 1,2-propanediol (PD) within the mammalian intestine has recently been hypothesized to provide certain pathogenic bacteria with a niche-specific carbon/nitrogen and energy source and provide a signal to enteric pathogens of their arrival in the small intestine. PD and EA metabolism may enhance competitive advantage for pathogen growth in other body compartments where these compounds are present. Pathogens such as Salmonella, Escherichia coli and Klebsiella utilise ethanolamine, while propanediol usage occurs in Yersinia, Klebsiella, Salmonella and Clostridium . These pathogens possess the pdu and/or eut operon(s), which encode the necessary metabolic machinery to utilise PD/EA in addition to a number of virulence genes that may be induced by pdu/eut regulatory genes. In a preliminary study, we detected PD and EA in human urine, demonstrated that urinary pathogens can metabolise these molecules in vitro and observed growth of bacteria possessing pdu/eut operons in human urine.