Among the single bacterial infection subgroups, the size of which allowed statistical analysis, i.e., E. coli (n = 11), Gram-negative strains (n = 31), Enterococcus species (n = 7), and Gram-positive strains (n = 13), serum hepcidin was elevated on day 0 compared to those of the healthy controls (p = 0.0001–0.0002) and was significantly reduced on day 7 (p = 0.001, 0.0004, 0.0156, and 0.0007, respectively) (Table 3). This evidence concerns the gene HAMP and bacterial infectious disease.