SepsisSIGMANCT07864818
Sepsis ICU Gut Microbiome Analysis
An observational study of Sepsis and Septic Shock, run by Union Hospital, Tongji Medical College, Huazhong University of Science and Technology at 1 site in China.
Trial summary
Sepsis is a life-threatening condition in which the body's response to an infection damages its own organs. This study aims to understand how the bacteria living in the gut change during sepsis and whether patterns of gut bacteria and chemicals found in stool can help identify patients at greater risk of death or poor… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Sepsis, Septic Shock
- What is being tested?
- Naturally Occurring Exposures
- How many people
- 180 participants
- Where
- 1 siteChina
- Study dates
- 15 Oct 2026to 30 Dec 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Adults aged 18 years or older receiving care in the ICU at Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, who meet the Sepsis-3 definition: suspected or confirmed infection with an acute infection-related increase in SOFA score of at least 2 points from baseline. Patients with or without septic shock will be consecutively enrolled. Eligible patients must be able to provide a spontaneously passed stool sample or undergo safe rectal swab collection within the baseline sampling window of 48 hours after T0. Written informed consent will be obtained from the patient or a legally authorized representative.
Who may be able to join
- Age ≥18 years.
- Receiving care in the ICU at Union Hospital, Tongji Medical College, Huazhong University of Science and Technology.
- Suspected or confirmed infection with an acute infection-related increase in the Sequential Organ Failure Assessment (SOFA) score of ≥2 points from baseline, meeting the Sepsis-3 definition.
- The research team determines that a spontaneously passed stool sample can be obtained, or a rectal swab can be collected safely, within the permitted baseline sampling window.
- Written informed consent is provided by participants who have decision-making capacity. For participants who temporarily lack decision-making capacity because of impaired consciousness, sedation, or critical illness, consent is provided by a legally authorized representative in accordance with applicable law. Once participants regain decision-making capacity, they will be informed again as soon as possible and asked to provide consent for continued participation.
Who cannot join
- Pregnancy or reasonable grounds for the investigator to suspect pregnancy.
- Active inflammatory bowel disease, major gastrointestinal surgery, or any other condition within the past 3 months that substantially alters intestinal anatomy and affects interpretation of the study results.
- Receipt of fecal microbiota transplantation before ICU admission.
- Active gastrointestinal bleeding, severe coagulopathy, anorectal surgery or lesions, or other conditions that make rectal swab collection unsafe, together with inability to obtain a spontaneously passed stool sample within the specified sampling window.
- Expected death within 24 hours and inability to complete informed consent and baseline procedures without interfering with emergency care.
- Refusal to participate by the participant or their legally authorized representative, or an investigator determination that the participant is unsuitable for enrollment based on safety, adherence, or data validity considerations.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site
Union Hospital, Tongji Medical College, Huazhong University of Science and Technology
Wuhan, Hubei, 430022
Jiancheng Zhang, 13554105815, zhjcheng1@126.com
Jiancheng Zhang, zhjcheng1@126.com
About this study
Official title: Sepsis ICU Gut Microbiome Analysis (SIGMA): A Prospective Observational Cohort Study of Gut Microbiota Structure, Functional Metabolic Features, and Composite Biomarkers in Adult ICU Patients
Sepsis is a life-threatening condition in which the body's response to an infection damages its own organs. This study aims to understand how the bacteria living in the gut change during sepsis and whether patterns of gut bacteria and chemicals found in stool can help identify patients at greater risk of death or poor recovery.
This observational study plans to enroll approximately 180 adults with sepsis receiving care in the intensive care unit (ICU) at Union Hospital, Tongji Medical College, Huazhong University of Science and Technology. All participants will receive usual medical care. The study will not assign experimental treatments or change treatment decisions.
Read more
Researchers will collect stool samples or, when stool is unavailable and sampling is safe, rectal swabs. Samples will be collected within the first 48 hours of the study, on days 3-5, on day 7, and near ICU discharge when feasible. Researchers will examine the types and amounts of gut bacteria. Samples from a selected group of participants will also be tested for chemicals related to metabolism. Information about illness severity, medicines, nutrition, and organ support will be collected from medical records.
Participants will be followed for 90 days, using medical records and telephone follow-up. The main clinical outcome is death from any cause within 28 days. Other outcomes include death and unplanned hospital readmission within 90 days. Researchers will assess whether gut bacterial patterns add useful information to routine clinical assessments and compare findings with available data from other sepsis studies.
- Conditions
- Sepsis, Septic Shock
- Being tested
- Naturally Occurring Exposures
- Medical subject headings
- Sepsis, Shock, Septic
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Naturally Occurring ExposuresOther
No study-directed intervention is assigned. All participants receive usual care as determined by their treating clinicians. Antibiotic use, other medications, nutrition, and organ support are recorded as naturally occurring exposures. Stool or rectal swab samples are collected at predefined time points to assess gut microbiota, with metabolite testing performed in a selected subgroup. These assessments are for research purposes and do not guide treatment decisions. Participants are followed for 90 days to assess survival and hospital readmission.
| Study group | Role | What they receive |
|---|---|---|
| Adult ICU Patients With Sepsis | Not described Receives: Other: Naturally Occurring Exposures |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Bacterial Taxonomic Units Included in the Locked Gut Microbiota Signature
Number of distinct bacterial taxonomic units included in the final locked gut microbiota signature, with a prespecified minimum of 15 units. Taxonomic units are represented by amplicon sequence variants (ASVs) or operational taxonomic units (OTUs) derived from 16S rRNA gene sequencing. The constituent units and their directions of association will be fixed after feature selection and internal validation.
Measured: Baseline (0-48 hours), days 3-5, day 7, and before ICU transfer or death, when feasible; outcomes through day 28
Secondary outcomes (10)
Change in Gut Microbiota Alpha Diversity Across Serial ICU Samples
Within-participant changes in gut microbiota alpha diversity derived from 16S rRNA gene sequencing across the prespecified sampling time points. Alpha diversity describes the diversity of bacterial taxonomic units within an individual sample.
Measured: Baseline (0-48 hours), days 3-5, day 7, and before ICU transfer or death, when feasible
Between-Sample Differences in Gut Microbiota Composition Across Serial ICU Samples
Differences in bacterial community composition between samples, measured using beta diversity metrics derived from 16S rRNA gene sequencing. Both within-participant changes over time and between-participant differences will be assessed.
Measured: Baseline (0-48 hours), days 3-5, day 7, and before ICU transfer or death, when feasible
Change in Relative Abundance of Gut Bacterial Taxonomic Units Across Serial ICU Samples
Within-participant changes in the relative abundance of bacterial ASVs or OTUs across sampling time points. Associations with illness severity, antibiotic exposure, nutrition, and organ support will be assessed using methods appropriate for compositional microbiome data.
Measured: Baseline (0-48 hours), days 3-5, day 7, and before ICU transfer or death, when feasible
Change in Measured Metabolite Abundance Across Serial ICU Samples
Within-participant changes in metabolite abundance measured by untargeted liquid chromatography-mass spectrometry in the prespecified nested metabolomics subgroup with qualified paired samples. Associations with gut microbiota features and organ dysfunction will be assessed. Measured metabolites will be distinguished from functions inferred from 16S sequencing.
Measured: Baseline (0-48 hours), days 3-5, day 7, and before ICU transfer or death, when feasible
Change in AUROC After Adding the Gut Microbiota Signature to the Clinical Model for 28-Day Death or Persistent Organ Dysfunction
Difference in the area under the receiver operating characteristic curve (AUROC) between a prespecified clinical model and the same model incorporating the locked gut microbiota signature for predicting 28-day death or persistent organ dysfunction. Performance will be assessed using patient-level nested cross-validation.
Measured: From T0 through day 28
Change in Brier Score After Adding the Gut Microbiota Signature to the Clinical Model for 28-Day Death or Persistent Organ Dysfunction
Difference in Brier score between a prespecified clinical model and the same model incorporating the locked gut microbiota signature for predicting 28-day death or persistent organ dysfunction. Lower Brier scores indicate better prediction accuracy. Performance will be assessed using patient-level nested cross-validation.
Measured: From T0 through day 28
Adjusted Association Between the Gut Microbiota Signature and 90-Day All-Cause Mortality
Association between the locked gut microbiota signature and death from any cause within 90 days, adjusted for prespecified clinical confounders. The estimated association and its 95% confidence interval will be reported. Survival status will be determined from medical records and telephone follow-up.
Measured: From T0 through day 90
Adjusted Association Between the Gut Microbiota Signature and First Unplanned Hospital Readmission Within 90 Days
Association between the locked gut microbiota signature and the first unplanned hospital readmission among participants discharged alive, adjusted for prespecified clinical confounders. Planned admissions and transfers for continuous treatment are excluded. Death will be treated as a competing event.
Measured: From index hospital discharge through day 90 after T0
AUROC of the Locked Gut Microbiota Signature in External Adult Sepsis Cohorts
Area under the receiver operating characteristic curve of the locked gut microbiota signature in eligible external adult sepsis cohorts with comparable microbiome features and clinical outcomes. External validation will be conducted after signature locking. Healthy reference datasets will be used only to characterize background variation.
Measured: Through day 28 in external cohorts with compatible outcomes
Number of Candidate Bacterial Taxa Assigned to Each Priority Tier
Number of candidate bacterial taxa assigned to each priority tier based on feature selection stability, cross-cohort reproducibility, associations with clinical outcomes, and supporting functional and metabolic evidence. Prioritized taxa will be identified for subsequent strain-level and mechanistic validation.
Measured: Serial ICU samples and clinical outcomes through day 9
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Oct 2026
- Study start15 Oct 2026 (estimated)
- Primary completion15 Oct 2027 (estimated)
- Study completion30 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for SepsisStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case only
- Time perspective
- Prospective
- Enrolment
- 180 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Union Hospital, Tongji Medical College, Huazhong University of Science and Technology
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jiancheng Zhang, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07864818
- Sponsor's protocol ID
- ZJC2026111
- Acronym
- SIGMA
- Status last verified
- Oct 2026
- First submitted
- 1 Oct 2026
- Last updated
- 8 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 8 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Sepsis ICU Gut Microbiome Analysis (SIGMA): A Prospective Observational Cohort Study of Gut Microbiota Structure, Functional Metabolic Features, and Composite Biomarkers in Adult ICU Patients
- ClinicalTrials.gov ID
- NCT07864818
- Acronym / sponsor ID
- SIGMA / ZJC2026111
- Conditions
- Sepsis, Septic Shock
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 180 participants (estimated)
- Lead sponsor
- Union Hospital, Tongji Medical College, Huazhong University of Science and TechnologyUniversity, hospital or other
- Study start
- 15 Oct 2026 (estimated)
- Primary completion
- 15 Oct 2027 (estimated)
- Study completion
- 30 Dec 2027 (estimated)
- First posted
- 8 Oct 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Sepsis is a life-threatening condition in which the body's response to an infection damages its own organs. This study aims to understand how the bacteria living in the gut change during sepsis and whether patterns of gut bacteria and chemicals found in stool can help identify patients at greater risk of death or poor recovery.
This observational study plans to enroll approximately 180 adults with sepsis receiving care in the intensive care unit (ICU) at Union Hospital, Tongji Medical College, Huazhong University of Science and Technology. All participants will receive usual medical care. The study will not assign experimental treatments or change treatment decisions.
Researchers will collect stool samples or, when stool is unavailable and sampling is safe, rectal swabs. Samples will be collected within the first 48 hours of the study, on days 3-5, on day 7, and near ICU discharge when feasible. Researchers will examine the types and amounts of gut bacteria. Samples from a selected group of participants will also be tested for chemicals related to metabolism. Information about illness severity, medicines, nutrition, and organ support will be collected from medical records.
Participants will be followed for 90 days, using medical records and telephone follow-up. The main clinical outcome is death from any cause within 28 days. Other outcomes include death and unplanned hospital readmission within 90 days. Researchers will assess whether gut bacterial patterns add useful information to routine clinical assessments and compare findings with available data from other sepsis studies.
Study design
- Observational model
- Case only
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Adult ICU Patients With Sepsis | – | Other: Naturally Occurring Exposures |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Adults aged 18 years or older receiving care in the ICU at Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, who meet the Sepsis-3 definition: suspected or confirmed infection with an acute infection-related increase in SOFA score of at least 2 points from baseline. Patients with or without septic shock will be consecutively enrolled. Eligible patients must be able to provide a spontaneously passed stool sample or undergo safe rectal swab collection within the baseline sampling window of 48 hours after T0. Written informed consent will be obtained from the patient or a legally authorized representative.
Key inclusion criteria (5 listed)
- Age ≥18 years.
- Receiving care in the ICU at Union Hospital, Tongji Medical College, Huazhong University of Science and Technology.
- Suspected or confirmed infection with an acute infection-related increase in the Sequential Organ Failure Assessment (SOFA) score of ≥2 points from baseline, meeting the Sepsis-3 definition.
- The research team determines that a spontaneously passed stool sample can be obtained, or a rectal swab can be collected safely, within the permitted baseline sampling window.
- Written informed consent is provided by participants who have decision-making capacity. For participants who temporarily lack decision-making capacity because of impaired consciousness, sedation, or critical illness, consent is provided by a legally authorized representative in accordance with applicable law. Once participants regain decision-making capacity, they will be informed again as soon as possible and asked to provide consent for continued participation.
Key exclusion criteria (6 listed)
- Pregnancy or reasonable grounds for the investigator to suspect pregnancy.
- Active inflammatory bowel disease, major gastrointestinal surgery, or any other condition within the past 3 months that substantially alters intestinal anatomy and affects interpretation of the study results.
- Receipt of fecal microbiota transplantation before ICU admission.
- Active gastrointestinal bleeding, severe coagulopathy, anorectal surgery or lesions, or other conditions that make rectal swab collection unsafe, together with inability to obtain a spontaneously passed stool sample within the specified sampling window.
- Expected death within 24 hours and inability to complete informed consent and baseline procedures without interfering with emergency care.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Naturally Occurring ExposuresNo study-directed intervention is assigned. All participants receive usual care as determined by their treating clinicians. Antibiotic use, other medications, nutrition, and organ support are recorded as naturally occurring exposures. Stool or rectal swab samples are collected at predefined time points to assess gut microbiota, with metabolite testing performed in a selected subgroup. These assessments are for research purposes and do not guide treatment decisions. Participants are followed for 90 days to assess survival and hospital readmission. | Other | Adult ICU Patients With Sepsis |
Primary outcome
Number of Bacterial Taxonomic Units Included in the Locked Gut Microbiota Signature
Time frame: Baseline (0-48 hours), days 3-5, day 7, and before ICU transfer or death, when feasible; outcomes through day 28
Number of distinct bacterial taxonomic units included in the final locked gut microbiota signature, with a prespecified minimum of 15 units. Taxonomic units are represented by amplicon sequence variants (ASVs) or operational taxonomic units (OTUs) derived from 16S rRNA gene sequencing. The constituent units and their directions of association will be fixed after feature selection and internal validation.
10 secondary outcomes
Change in Gut Microbiota Alpha Diversity Across Serial ICU Samples
Time frame: Baseline (0-48 hours), days 3-5, day 7, and before ICU transfer or death, when feasible
Between-Sample Differences in Gut Microbiota Composition Across Serial ICU Samples
Time frame: Baseline (0-48 hours), days 3-5, day 7, and before ICU transfer or death, when feasible
Change in Relative Abundance of Gut Bacterial Taxonomic Units Across Serial ICU Samples
Time frame: Baseline (0-48 hours), days 3-5, day 7, and before ICU transfer or death, when feasible
Change in Measured Metabolite Abundance Across Serial ICU Samples
Time frame: Baseline (0-48 hours), days 3-5, day 7, and before ICU transfer or death, when feasible
Change in AUROC After Adding the Gut Microbiota Signature to the Clinical Model for 28-Day Death or Persistent Organ Dysfunction
Time frame: From T0 through day 28
Change in Brier Score After Adding the Gut Microbiota Signature to the Clinical Model for 28-Day Death or Persistent Organ Dysfunction
Time frame: From T0 through day 28
Adjusted Association Between the Gut Microbiota Signature and 90-Day All-Cause Mortality
Time frame: From T0 through day 90
Adjusted Association Between the Gut Microbiota Signature and First Unplanned Hospital Readmission Within 90 Days
Time frame: From index hospital discharge through day 90 after T0
AUROC of the Locked Gut Microbiota Signature in External Adult Sepsis Cohorts
Time frame: Through day 28 in external cohorts with compatible outcomes
Number of Candidate Bacterial Taxa Assigned to Each Priority Tier
Time frame: Serial ICU samples and clinical outcomes through day 9
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 Oct 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Sepsis and Septic Shock, run by Union Hospital, Tongji Medical College, Huazhong University of Science and Technology at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 8 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Jiancheng Zhang (8613554105815, zhjcheng1@126.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of Bacterial Taxonomic Units Included in the Locked Gut Microbiota Signature (time frame: Baseline (0-48 hours), days 3-5, day 7, and before ICU transfer or death, when feasible; outcomes through day 28). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 Oct 2026.