Casein hydrolysate and derived peptides stimulate mucin secretion and gene expression in human intestinal cells

The present study was undertaken to explore if a casein hydrolysate and four component peptides with probable ability to interact with opioid receptors can exert a stimulatory effect on mucin production in human intestinal cells (HT29-MTX). αS1-Casein fragments 143–149 (AYFYPEL) and 144–149 (YFYPEL), and the casein hydrolysate, significantly increased expression of MUC5AC, the major secreted mucin gene in this cell line, over 1.7-fold basal level after 4 h of exposure. The determination of mucin-like glycoproteins showed a higher effect on mucin secretion by the casein hydrolysate (210% of controls) than that of AYFYPEL and YFYPEL (around 160%). Therefore, peptides or other components may participate in the activity of the hydrolysate in a synergistic way or through a non-opioid mechanism. In conclusion, a casein hydrolysate and two derived peptides, AYFYPEL and YFYPEL, promote the mucin production and may support the development of functional foods to improve mucus barrier and its protective role in gastrointestinal diseases.