Microbiome and Metabolic Immune Mechanisms in Sepsis-Associated Encephalopathy

Sepsis associated encephalopathy (SAE) is common in patients with sepsis, and the occurrence of SAE often indicated adverse outcomes. In recent years, the imbalance of the intestinal microbiota and metabolites have been found to be related to the occurrence of SAE, and this regulation is often accompanied by the activation of the immune system. Possible mechanism still needs to be clarified. Intestinal flora disturbances and altered metabolic profiles are often accompanied by changes in the levels of small molecule metabolites, some of which are critical for the maintenance of brain functional homeostasis, such as short-chain fatty acids (SCFAs). These changes further affect the permeability of the blood-brain barrier and the activation of the central and peripheral immune system, and finally promote the release of inflammatory cytokines and the activation of immune cells. Targeting intestinal microbiota profile, small molecule metabolite, or neurostimulation regulation may be potential therapeutic methods for SAE, such as amino acid supplements, microbiota transplantation, or other metabolite level regulation drugs. Our review will summarize the intestinal flora disturbances, metabolic profiles, neuro-immunoinflammatory changes and related possible drug intervention. These findings may provide the possibility for further exploration of the mechanisms and treatment methods of SAE.