Table 4.

Probiotic mechanism of action.

Mechanism of Action
Microbiological	Modulation of gut microbiota composition Competitive binding to intestinal receptors (prevention of pathogen invasion) Bacteriocin production (preventing the growth of pathogens)
Structural	Modulation of epithelial barrier function Production of short-chain fatty acids (strengthening of the intestinal barrier with anti-inflammatory action) Regulation of tight junction protein expression (reduced antigen transfer)
Immunologic	Probiotics play a role in host innate and adaptive immune responses by modulating immune cells such as dendritic cells (DCs), macrophages, and B and T lymphocytes Modulation of Th1/Th2 lymphocyte ratio Activation of T regulatory (Treg) cells Maturation of B cells into immunoglobulin (Ig)A-producing plasma cells.