From the Research
The gastrointestinal (GI) tract is lined by several specialized cell types that work together to facilitate digestion, absorption, and protection, including enterocytes, goblet cells, enteroendocrine cells, Paneth cells, M cells, tuft cells, and stem cells, as well as specialized parietal and chief cells in the stomach. The main epithelial cells include enterocytes (absorptive cells), which are the most abundant and responsible for nutrient absorption; goblet cells, which secrete protective mucus; enteroendocrine cells, which release hormones that regulate digestion; Paneth cells, found in the small intestine crypts, which secrete antimicrobial peptides; M cells, which sample antigens and are important for immune surveillance; tuft cells, which detect parasites and initiate immune responses; and stem cells located in the crypts, which continuously regenerate the epithelium 1. Additionally, the stomach has specialized parietal cells that secrete hydrochloric acid and intrinsic factor, and chief cells that produce pepsinogen. This diverse cellular composition allows the GI tract to perform its complex functions of digestion, absorption, and defense against pathogens while maintaining a selective barrier between the body and the external environment. Some of the key functions of these cells include:
- Enterocytes: responsible for nutrient absorption
- Goblet cells: secrete protective mucus
- Enteroendocrine cells: release hormones that regulate digestion
- Paneth cells: secrete antimicrobial peptides
- M cells: sample antigens and are important for immune surveillance
- Tuft cells: detect parasites and initiate immune responses
- Stem cells: continuously regenerate the epithelium The GI tract's complex functions are essential for maintaining overall health, and any disruption to the balance of these cell types can lead to various diseases and disorders, such as inflammatory bowel disease (IBD) 2.