Fig. 6.

Schematic diagram of the different pathways for probiotic-mediated pathogen control. At (1), probiotics may attenuate their physical and chemical surroundings (epithelial cell receptors, mucus, nutrients, pH, peristaltism, and tight junctions). At (2), probiotic supplements may yield biological molecules like antibiotics, bacteriocins, or peroxide-containing antimicrobial characteristics. At (3), probiotics can cause immune regulation, either by interfering with dendritic cells, which can, in effect, alter the segregation of naive T lymphocytes to Th1, 2, or Treg cells, corresponding to unique inductions of cytokines or by humoral response via IgA-based cells and their secretive IgAs (Travers et al. 2011b)