Pathogenic bacteria that succeed in penetrating the wall of the large intestine into the blood circulation are removed or destroyed by

Intestinal Epithelial Cells (IEC)

Explanation:

Polarized intestinal epithelial cells (IEC), as well as the resident microflora, provide a barrier that guards against microbial invasion The necessity for the epithelium to maintain an intact barrier between lumen bacteria and the lamina propria is exemplified by the consequences after the barrier function is altered Impairment of the barrier function of the intestinal epithelium may be a predominant mechanism in the pathogenesis of inflammatory bowel disease (IBD)