Temperature-treated Gluten Proteins in Gluten-Friendly™ Bread Increase Mucus Production and Gut-Barrier Function in Human Intestinal Goblet Cells

The effects of a control bread (CB) and a Gluten Friendly™ bread (GFB) on intestinal epithelium mucus production and barrier function in healthy human mucus-secreting goblet cells HT-29-16E were investigated. Mucus production in cells exposed to digested breads (GFB and CB) was preliminarily investigated using staining techniques, Periodic Acid-Schiff (PAS) and Alcian blue (AB), and MUC2 and MUC3 were also quantified by ELISA assay. The barrier function of the cell monolayer was evaluated by trans-epithelial electrical resistance (TEER) measurements. GFB increased the secretion of mucins, expressed as the level of PAS and AB staining in comparison with the control. MUC3 levels were not affected, whereas higher MUC2 concentrations (P < 0.01) were found on cells treated with GFB compared to the control. Additionally, significantly higher TEER values were observed after treatment with both CB and GFB in comparison with the control (P < 0.01), with GFB having a significantly higher effect than CB (P < 0.01).