Sepsis is a major cause of morbidity and mortality in intensive care units. Sepsis-associated liver injury (SALI) and sepsis-associated acute kidney injury (S-AKI) are common complications associated with adverse clinical outcomes. Altered gut microbial diversity, microbial metabolites, intestinal barrier dysfunction, and systemic inflammation may contribute to hepato-renal injury during sepsis; however, prospective longitudinal evidence in patients with SALI and S-AKI remains limited. This prospective, multicenter, longitudinal observational cohort study will enroll adult patients with sepsis across five medical centers and healthy adult volunteers as a baseline reference cohort. For patients with sepsis, stool and blood samples will be collected on Day 0, Days 3-5, Days 7-10, and Days 14-20 after sepsis diagnosis. Healthy volunteers will provide a single baseline stool and blood sample at enrollment. Fecal microbial alpha diversity and community structure will be assessed by metagenomic sequencing and bioinformatic analysis. Plasma metabolites, including total short-chain fatty acids, indoxyl sulfate, and additional targeted plasma metabolites, will be measured by ultra-high-performance liquid chromatography-tandem mass spectrometry. Intestinal barrier and clinical biomarkers will also be assessed. The primary objectives are to evaluate the associations between baseline fecal microbial alpha diversity, measured by the Shannon diversity index, and SALI and S-AKI occurring within 7 days after sepsis diagnosis. Secondary objectives include evaluating the associations of baseline fecal microbial beta diversity with SALI and with S-AKI occurring within 7 days after sepsis diagnosis, characterizing longitudinal changes in fecal microbial alpha diversity, measuring plasma metabolite and intestinal biomarker concentrations at prespecified time points, and assessing 28-day all-cause mortality. Exploratory multi-omics analyses will evaluate Proteobacteria and additional microbial taxa, microbial functional genes, metabolites, and host biomarkers. This study aims to identify candidate biomarkers and biological pathways relevant to hepato-renal injury in sepsis.
Study Type
OBSERVATIONAL
Enrollment
200
First Affiliated hospital of zhejiang university school of medicine
Hangzhou, Zhejiang, China
RECRUITINGAssociation of Baseline Gut Microbial Alpha Diversity With Sepsis-Associated Acute Kidney Injury
Sepsis-associated acute kidney injury (S-AKI) occurring from Day 0 through Day 7 after sepsis diagnosis, assessed according to Kidney Disease: Improving Global Outcomes (KDIGO) criteria using serum creatinine and urine output obtained from routine clinical laboratory testing and medical records. Baseline fecal microbial alpha diversity will be measured using the Shannon diversity index (unitless), calculated from metagenomic sequencing and bioinformatic analysis of a stool sample collected on Day 0 or, if unavailable, within 24 hours after sepsis diagnosis. The association between the Shannon diversity index and S-AKI will be estimated using multivariable logistic regression and reported as an adjusted odds ratio per 1-unit increase in the Shannon diversity index.
Time frame: Baseline stool sample collected on Day 0 or within 24 hours after sepsis diagnosis; S-AKI assessed from Day 0 through Day 7 after sepsis diagnosis.
Association of Baseline Gut Microbial Alpha Diversity With Sepsis-Associated Liver Injury
Sepsis-associated liver injury (SALI) occurring from Day 0 through Day 7 after sepsis diagnosis, assessed using routine clinical laboratory measurements. SALI is defined by at least one of the following: total bilirubin (TBIL) \>2 mg/dL and international normalized ratio (INR) \>1.5; alanine aminotransferase (ALT) ≥5 times the upper limit of normal (ULN); alkaline phosphatase (ALP) ≥2 times ULN; or ALT ≥3 times ULN with TBIL ≥2 times ULN. Baseline fecal microbial alpha diversity will be measured using the Shannon diversity index (unitless), calculated from metagenomic sequencing and bioinformatic analysis of a stool sample collected on Day 0 or, if unavailable, within 24 hours after sepsis diagnosis. The association between the Shannon diversity index and SALI will be estimated using multivariable logistic regression and reported as an adjusted odds ratio per 1-unit increase in the Shannon diversity index.
Time frame: Baseline stool sample collected on Day 0 or within 24 hours after sepsis diagnosis; SALI assessed from Day 0 through Day 7 after sepsis diagnosis.
Association of Baseline Fecal Microbial Beta Diversity With Sepsis-Associated Liver Injury
Sepsis-associated liver injury (SALI) occurring from Day 0 through Day 7 after sepsis diagnosis, assessed using routine clinical laboratory measurements according to the prespecified SALI criteria. Baseline fecal microbial beta diversity will be assessed using Bray-Curtis dissimilarity (unitless), calculated from metagenomic sequencing data and bioinformatic taxonomic profiling of a stool sample collected on Day 0 or, if unavailable, within 24 hours after sepsis diagnosis. Differences in baseline fecal microbial community composition between the SALI group and the sepsis control group will be evaluated using permutational multivariate analysis of variance (PERMANOVA) and reported as the PERMANOVA R-squared value (R²; unitless).
Time frame: Baseline stool sample collected on Day 0 or within 24 hours after sepsis diagnosis; SALI assessed from Day 0 through Day 7 after sepsis diagnosis.
Association of Baseline Fecal Microbial Beta Diversity With Sepsis-Associated Acute Kidney Injury
Sepsis-associated acute kidney injury (S-AKI) occurring from Day 0 through Day 7 after sepsis diagnosis, assessed according to Kidney Disease: Improving Global Outcomes (KDIGO) criteria using serum creatinine and urine output obtained from routine clinical laboratory testing and medical records. Baseline fecal microbial beta diversity will be assessed using Bray-Curtis dissimilarity (unitless), calculated from metagenomic sequencing data and bioinformatic taxonomic profiling of a stool sample collected on Day 0 or, if unavailable, within 24 hours after sepsis diagnosis. Differences in baseline fecal microbial community composition between the S-AKI group and the sepsis control group will be evaluated using permutational multivariate analysis of variance (PERMANOVA) and reported as the PERMANOVA R-squared value (R²; unitless).
Time frame: Baseline stool sample collected on Day 0 or within 24 hours after sepsis diagnosis; S-AKI assessed from Day 0 through Day 7 after sepsis diagnosis.
Total Plasma Short-Chain Fatty Acid Concentration
Total plasma short-chain fatty acid concentration will be reported as a single aggregate value at each prespecified time point. It will be calculated as the sum of plasma acetate, propionate, and butyrate concentrations, all measured in μmol/L by ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).
Time frame: Days 0, 3-5, 7-10, and 14-20 after sepsis diagnosis.
Plasma Indoxyl Sulfate Concentration
Plasma indoxyl sulfate concentration will be measured by UPLC-MS/MS and reported in μmol/L at each prespecified time point.
Time frame: Days 0, 3-5, 7-10, and 14-20 after sepsis diagnosis.
Fecal Calprotectin Concentration
Fecal calprotectin concentration will be measured using a validated fecal calprotectin immunoassay and reported in μg/g of stool at each prespecified time point.
Time frame: Days 0, 3-5, 7-10, and 14-20 after sepsis diagnosis.
28-Day All-Cause Mortality
All-cause mortality within 28 days after sepsis diagnosis, reported as the percentage (%) of enrolled participants who die. Vital status will be ascertained from medical records and follow-up contact.
Time frame: Day 28 after sepsis diagnosis.
Longitudinal Change in Fecal Microbial Alpha Diversity Among Patients With Sepsis
Fecal microbial alpha diversity will be measured using the Shannon diversity index (unitless), calculated from metagenomic sequencing data and bioinformatic analysis of stool samples collected on Day 0, Days 3-5, Days 7-10, and Days 14-20 after sepsis diagnosis. Longitudinal changes in the Shannon diversity index among patients with sepsis will be evaluated using a linear mixed-effects model accounting for repeated measurements within participants. The outcome will be reported as the model-estimated mean Shannon diversity index (unitless) at each prespecified time point. Healthy volunteers will not be included in this longitudinal analysis because stool samples are collected only once at enrollment.
Time frame: Day 0 through Days 14-20 after sepsis diagnosis, with assessments on Day 0, Days 3-5, Days 7-10, and Days 14-20.
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