What do intestinal epithelial cells do?

Intestinal epithelial cells form an outer protective layer. The cells have multifold functions including:

Nutrients absorption: Cells called enterocytes take up nutrients from digested food, including sugars, amino acids, fatty acids, vitamins, and minerals. Their tiny surface projections, called microvilli, provide a large area for absorption.

Protect the gut: Protecting the intestinal lining acts as a barrier between the contents of the gut and the rest of the body. Connections called tight junctions help control what can pass through the lining and prevent unwanted substances from entering easily.

Mucus production: Goblet cells produce mucus that coats the intestinal surface. This layer protects epithelial cells from digestive substances and prevents harmful microbial load migrating directly to the gut.

Supports immune function: The intestinal lining constantly encounters microbes or other foreign materials. Epithelial cells help recognise these signals and communicate with immune cells, contributing to the gut’s defence system.

Communication: Response to nutrients, microbial signals, and changes in the intestinal environment. They release signalling molecules that influence digestion, immunity, and tissue repair.

Renew and repair the lining: Normally the intestinal lining is exposed to mechanical and chemical stress. Intestinal stem cells regularly produce new epithelial cells, allowing damaged or ageing cells to be replaced.

Thus, intestinal epithelial cells support various functions including drug absorption, gut barrier function, intestinal toxicity, microbiome interactions, and gastrointestinal diseases.