Gut Microbiota Analysis in IAI Patients With Sepsis-associated Liver Dysfunction

With the rapid development of intensive care medicine, the mortality of patients with sepsis has decreased over the past decade, but it is still the leading cause of death in intensive care unit (ICU). As an important immune and metabolic organ, the liver plays a crucial role in host defense against invading pathogens and endotoxins, as well as maintenance of metabolic and immunological homeostasis. Some studies indicate that sepsis-associated liver dysfunction (SALD) has a substantial impact on the severity and prognosis of sepsis.Intra-abdominal infections (IAI) are the second leading source of infection for sepsis after pneumonia in ICU, and are often related to high morbidity and mortality rates. Studies had found that the incidence of SALD in IAI patients was considerably higher than that of general population with sepsis. Moreover, the incidence of acute gastrointestinal injury (AGI) in IAI patients was also much higher than that in sepsis patients with other site infections, as well as the degree of AGI was more serious according to guidelines proposed by the European Society of Intensive Care Medicine (ESICM) in 2012. IAI can directly cause AGI, and a subset of patients usually progress to increased intra-abdominal pressure, which further aggravates AGI.The pathogenesis of SALD remains unclear so far, and its mechanism is complicated and elusive. Nevertheless, the unique anatomical structure of the liver make it has close association with the gut, growing evidence indicates that the gut microbiota and related metabolites are related to several liver disease. In case of sepsis, gut microbiota disorder and low microbial diversity can cause severe liver injury. An important mechanism for this phenotype is the gut-liver axis, which refers to gut microbial metabolites and nutrients are transported to the liver through the portal vein and hepatic artery to maintain the healthy metabolism of liver.Therefore, we initially conducted a retrospective study to investigate the relationship between the occurrence of AGI and SALD among IAI patients. Subsequently, a prospective study was performed to analyze and compare the diversity and composition of gut microbiota in IAI patients with or without SALD, respectively, and the dynamic changes in the gut microbiota during the first week after ICU admission were also investigated.

Inclusion Criteria:Adult patients (≥18 years)Diagnosed as Intra-abdominal infections (IAH)Diagnosed as sepsis 3.0Exclusion Criteria:Discharged or died within 48 hours afterenrollmentKnown serious chronic liver disease, such as decompensated cirrhosis and end-stage liver cancerHospitalization due to primary hepatobiliary disease, such as trauma, hepatitis, cholelithiasis, etc;Other causes of liver injury include: drugs, poisons, etcPregnancy.