MUC5AC and infection: The gut epithelial barrier consists of epithelial cells and intercellular junction proteins that play important roles in preventing inflammation and infection.48 An increase in the abundance of beneficial microbes in the gut can improve the integrity of the intestinal barrier.49 Cheng et al. 50 transplanted the fecal microbiota of healthy Jinhua pigs into K88-infected piglets, which were found to have improved intestinal morphology, reduced intestinal permeability and enhanced expression of mucin and mucosal tight junction proteins as a result of the transplant.