This effect might be exacerbated by low fiber diets, a hallmark of children in the US,79 since recent studies have suggested that a shift from microbes utilizing carbohydrate to mucin was able to stimulate IBD phenotypes.80 This combination of early life gut instability, opportunistic invasion, and suboptimal diet could also have lasting impacts on the hosts’ immune system.81 While the severity and faster progression of childhood IBD is likely multifaceted, these models suggest that gut instability and the invasion of IBD-typical microbes might play a more important role in pediatric IBD. Here, MUC5AC is linked to inflammatory bowel disease.