KLB and bacterial infectious disease: Here we show that Salmonella infection disturbs the homeostasis of the FGF15/19-FGFR4 axis by down-regulating the expression of Fgf15, Fgfr4 and Klb. To our knowledge, these results constitute the first demonstration of a pathophysiological effect of bacterial infections over the FGF15/19-FGFR4 endocrine axis.