N-glycosylation is essential for ileal ASBT function and protection against proteases.

The bile acid transporter ASBT is a glycoprotein responsible for active absorption of bile acids. Inhibiting ASBT function and bile acid absorption is an attractive approach to lower plasma cholesterol and improve glucose imbalance in diabetic patients. Deglycosylation of ASBT was shown to decrease its function.

Common food additive carrageenan stimulates Wnt/ β-catenin signaling in colonic epithelium by inhibition of nucleoredoxin reduction.

Exposure to the common food additive carrageenan was previously associated with increased Wnt9A expression and increased cytoplasmic β-catenin in human colonic epithelial cells. In this report, exposure of human colonic epithelial cells in culture and of mouse colonic epithelium in vivo to low concentrations of carrageenan is shown to activate the Wnt/β-catenin signaling pathway, leading to increases in nuclear β-catenin, T-cell factor/lymphoid enhancer factor activation, and cyclin D1 expression and decline in bone morphogenetic protein-4. These effects are mediated through carrageenan-induced reactive oxygen species (ROS), and inhibited by the ROS scavenger Tempol.