In adults, where are the stem cells that make new to protect intestines?

The stem cells that make new cells to protect the intestines are located in the bottom of the crypts of Lieberkühn, which are small, finger-like protrusions that line the small intestine and colon. These stem cells are called crypt base columnar cells (CBCs) and are responsible for producing the various cell types that make up the intestinal lining, including enterocytes (absorptive cells), goblet cells (mucus-secreting cells), Paneth cells (antimicrobial peptide-secreting cells), and enteroendocrine cells (hormone-secreting cells). CBCs are constantly dividing to produce new cells that migrate up the crypt and differentiate into the different types of intestinal cells. This process of cell renewal, known as intestinal epithelial cell turnover, is essential for maintaining the integrity and function of the intestinal lining.