Function of the large intestine and its interaction with the brain after ischemic stroke: a comprehensive literature review

The large intestine, part of the distal gastrointestinal tract, is vital for water and electrolyte absorption and microbial fermentation. It is also a significant immune organ endowed with an extensive and intricate neural network. Intestinal epithelial cells are essential for endocrine regulation and maintaining the integrity of the intestinal barrier. Stroke, a leading cause of adult mortality and disability, occurs when there is a lack of oxygen to the brain and involves complex cerebrovascular dynamics that significantly impact systemic functions. In this framework, the gut-brain axis—the bidirectional circuitry connecting the gut and the central nervous system (CNS)—emerges as a critical interface. This review examines the immunological, neurological, endocrine, and barrier functions of the large intestine and explores its interplay with stroke pathophysiology. By detailing the interrelation between stroke and large intestinal functions, this paper aims to provide a foundational reference for advancing research into their intertwined mechanisms and identifying potential therapeutic targets.