MUC5AC and obesity due to melanocortin 4 receptor deficiency: Consistent with our findings, several studies have shown that HFD-fed animals show increased intestinal expression of pro-inflammatory mediators (TNF, IL-1β, IL-6), along with morphological alterations, disrupted mucin biosynthesis, and impaired mucosal barrier integrity, features that collectively underscore the central role of obesity in promoting gut inflammation and increased intestinal permeability [24,25,44].