In healthy humans, MUC2 O-glycosylation is uniform while it is altered in patients with active ulcerative colitis and associated with increased inflammation.37 38 A different profile was also observed in human colon cancer, linked to tumour metastatic potential and poor prognosis.39 40 Understanding the pattern of mucin glycosylation in patients with obesity and metabolic disorders, and how these could be modulated by nutritional treatments, could be useful in inducing the colonisation of specific bacteria associated with beneficial effects. This evidence concerns the gene MUC5AC and obesity due to melanocortin 4 receptor deficiency.