Table 1.

Mucus composition at different mucosal surfaces.

Mucosal Surface	Secreted Mucins	Adherent mucins	Other significant components	Reference
Respiratory tract	MUC2, MUC5AC, MUC5B, MUC19, MUC7	MUC1, MUC4, MUC12, MUC15, MUC20	Microbes, surfactants, phospholipids, immunoglobulins	15–25
Stomach	MUC5AC, MUC6	MUC1, MUC4, MUC12, MUC13, MUC15, MUC17	HCl, phospholipids	16,20,21,26–28
Small intestine	MUC2, MUC6	MUC1, MUC3A/B, MUC12, MUC13, MUC15, MUC17	Bile salts, phospholipids, microbes, immunoglobulins	21,25,27-33
Large intestine	MUC2	MUC1, MUC3A/B, MUC4, MUC12, MUC13, MUC15, MUC17, MUC20	Microbes, phospholipids, immunoglobulins	16,20,21,25,28–35
Cervicovaginal tract	MUC5AC, MUC5B, MUC6	MUC1, MUC4, MUC12, MUC16	Lactobacilli and other microbes, immunoglobulins	16,17,20,25,27,36–42
Eye	MUC2, MUC5AC, MUC19	MUC1, MUC4	Antimicrobial peptides, immunoglobulins	16,20,25,43–48