In serum, 8 of the 9 volunteers (89%) exhibited an increase in antibody responses against CfaB compared to pre-infection levels, and the maximum MFI fold increase was seen 3 months after ingesting the dose, with a 9.6-fold increase in antigen specific IgA (p = 0.008) and a 12.5-fold increase in antigen specific IgG/IgM (p = 0.008) (Figure 2). This evidence concerns the gene CFB and infection.