Table 1. Mucus production and immunomodulatory molecules and pathways.

Trigger	Cell	Pathway	Result
TLR ligand	Sentinel goblet cells (senGCs)	TLR, MyD88, NLRP6	Exocytosis of Muc2 and adjacent responsive GCs are induced to secrete MUC2
adverse conditions such as bacterial infection or antibioticS	GCs in the small intestine and distal colon	Myd88, EGRF and p42/p44 MAPK	Inhibit the formation of GAPs

Mucin production is regulated by many factors, including temperature, pH value, infection, and inflammatory factors. When the body is threatened by bacterial infection, it will activate the GCs pathway and secrete mucus to prevent pathogens from approaching the intestinal epithelium.