MUC5AC and inflammatory bowel disease: However, in IBD, dysregulation of these macrophages compromises mucus integrity.9 Aberrantly activated macrophages produce proinflammatory cytokines that impair goblet cell function, reduce mucin secretion, and disrupt the mucus layer, thereby increasing the vulnerability of the epithelium to damage and infection.10 Additionally, intestinal macrophages may influence the composition of the gut microbiota, which in turn can impact mucin degradation and mucus layer integrity.