Figure 2.

Activation of intestinal immunology via probiotics and prebiotics (by figdraw). The MAMPs of probiotics can be recognized via PPRs expressed on the epithelial cell membrane, thereby activating the transcription of cytokines through signaling pathways such as NF-κB. Cytokines produced by intestinal epithelial cells can trigger the native immune response in the mucous layer. For instance, this molecule can transactivate monocytes and dendritic cells to secrete chemokines and other cytokines (e.g., TNF) that further promote the proliferation and differentiation of T lymphocytes. Moreover, B cells rapidly respond to these signals by differentiating into plasma cells and secreting antibodies (e.g., IgA) into the intestinal lumen. The IgA forms a line of defense on epithelial cells and binds to receptors on the surface of pathogenic bacteria, promoting bacterial lysis and clearance.