Role of the intestinal microbiota in sepsis-associated encephalopathy

Sepsis-associated encephalopathy (SAE) is a secondary cerebral dysfunction of the central nervous system (CNS) caused by sepsis and is associated with high mortality rate and poor prognosis. It significantly affects the quality of life of survivors. The pathological mechanisms associated with SAE include dysfunction of the blood–brain barrier (BBB), activation of glial cells, ischemic injury, leukocyte transmigration, and disturbances in neurotransmitters. The mechanisms of SAE interact with and contribute to its development. Numerous studies have demonstrated that the intestinal microbiota affects not only the health of the gut but also that of other organs. Throughout the progression of SAE, alterations in the gut microbiome composition lead to the production of toxic substances that damage the intestinal barrier and enter the bloodstream. This damage negatively affects BBB permeability and initiates a cascade of neuroinflammatory responses that result in neuronal injury. Conversely, specific microbiome-derived derivatives play exhibit a neuroprotective role in regulating brain function. Therefore, gut–brain crosstalk may be a crucial factor in brain dysfunction. This paper reviews the relationship between the intestinal microbiota and SAE, aiming to explore the role of the intestinal microbiota in SAE and potential therapeutic targets.