Heightened colonic cytokine levels in the WT-infected group also correlated with significant increases in serum GCSF, IL-1β, IL-3, IL-6, IL-17, CXCL1, CXCL9, MCP-1, TNF-α and TREM at the peak of infection (48-hours), when compared to the TcdA−TcdB−CDT+ and uninfected groups (Supplementary Figure 1d, p< .05). This evidence concerns the gene CXCL1 and infection.