FMT for Lung and Associated-organ Rescue Efficacy in ARDS Patients

Union Hospital, Tongji Medical College, Huazhong University of Science and Technology150 enrolled

Overview

Acute respiratory distress syndrome (ARDS) represents a substantial global health burden. In the intensive care unit (ICU), the concurrent administration of antibiotics, opioids, proton pump inhibitors (PPIs), vasoconstrictors, and parenteral nutrition-compounded by the intrinsic severity of critical illness-induces profound gut microbiota dysbiosis. Accumulating preclinical and clinical evidence indicates that such intestinal dysregulation may trigger distal immunomodulatory and microbial shifts in the lung via the gut-lung axis, thereby contributing to pulmonary microecological imbalance and impairing recovery trajectories. Although pulmonary microecology has garnered increasing scientific attention, the causal and temporal relationship between gut dysbiosis and the establishment or exacerbation of pulmonary microbial dysbiosis in ARDS remains inadequately characterized. As a result, it is currently unclear whether gut dysbiosis serves as a primary pathogenic driver, a disease-amplifying factor, or a secondary epiphenomenon in the context of ARDS-associated lung injury. Fecal microbiota transplantation (FMT) is a targeted microbiome-modulating intervention that involves the transfer of functionally diverse, minimally processed microbial communities from comprehensively screened healthy donors to restore ecological stability and functional redundancy in the recipient gut. Robust clinical data demonstrate that FMT effectively decolonizes the gastrointestinal tract of multidrug-resistant organisms (MDROs) and reduces the incidence of secondary infections in immunocompetent, non-critically ill populations. Over the past decade, FMT has demonstrated reproducible efficacy in recurrent Clostridioides difficile infection and emerging promise in select extra-intestinal inflammatory conditions-highlighting its capacity as a mechanism-informed strategy for systemic host-microbe recalibration. Given the established role of the gut as a reservoir for enteric pathogens implicated in sepsis, hospital-acquired bloodstream infections, and ventilator-associated pneumonia (VAP), we propose a prospective, single-center, open-Label, randomized controlled trial (RCT) enrolling mechanically ventilated adults with ARDS. The primary objective is to evaluate whether adjunctive FMT-delivered via nasojejunal tube-decrease 28-day mortality.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Eligibility

Sex: ALLMin age: 18 YearsMax age: 70 Years

Medical Language ↔ Plain English

Inclusion Criteria: 1. Age 18-70 years, inclusive, irrespective of sex or ethnic background; 2. Admission to the intensive care unit (ICU) within 24-48 hours; 3. Anticipated ICU length of stay of ≥7 days, as determined by the attending intensivist prior to enrollment; 4. Diagnosis of acute respiratory distress syndrome (ARDS) meeting the new global definition; 5. Provision of written informed consent by the participant or legally authorized representative. Exclusion Criteria: 1. Severe systemic infection during early resuscitation, accompanied by hemodynamic instability, profound tissue hypoperfusion, or life-threatening electrolyte and acid-base disturbances; 2. Clinician-assessed high risk of mortality within 5 days, or presence of formal treatment-limiting directives (e.g., do-not-intubate or do-not-resuscitate orders); 3. Active gastrointestinal bleeding or perforation consistent with severe intestinal barrier dysfunction; 4. Inability to tolerate enteral nutrition providing ≥50% of estimated caloric requirements due to structural intestinal pathology-including fibrotic bowel stenosis or high-output enterocutaneous fistula; 5. Planned abdominal surgery or history of abdominal surgery within 14 days prior to enrollment; 6. Confirmed diagnosis of fulminant colitis or toxic megacolon; 7. Neutropenia defined as absolute neutrophil count \< 1.5 × 10⁹/L; 8. Recent exposure to high-risk immunosuppressive or cytotoxic agents within the preceding 3 months, including but not limited to: rituximab (within 6 months), anthracyclines (e.g., doxorubicin), or systemic corticosteroids at ≥20 mg/day prednisone-equivalent dose for ≥4 consecutive weeks; 9. Pregnancy or lactation; 10. Participation in another interventional clinical trial within 3 months prior to enrollment or ongoing at the time of study entry.

Outcomes

Primary Outcomes

28-day all-cause mortality rate

The mortality rate within 28 days after inclusion in the study

Time frame: Within 28 days after inclusion

Secondary Outcomes

Dynamic changes in the total SOFA score

Change in total SOFA score from randomization (baseline) to 168 hours post-intervention

Time frame: Within 24 hours before FMT intervention, and on days 1, 2, 3, 4, 5, 6 and 7 after FMT initiation

Changes in pulmonary microbiota diversity

Metagenomics profiling of BALF was conducted to compare the pulmonary microbiota between the two groups. Metagenomic sequencing will be performed to analyze the dynamic changes in α-diversity (Shannon index), β-diversity, and the relative abundance of specific microbial taxa, including the Firmicutes-to-Bacteroidetes ratio, and potential pathogens.

Time frame: Within 24 hours before FMT intervention, and at 72 hours after last FMT administration

Changes in intestinal microbiota diversity

Metagenomics profiling of rectal swabs was conducted to compare the gut microbiota between the two groups. Metagenomic sequencing will be performed to analyze the dynamic changes in α-diversity (Shannon index), β-diversity, and the relative abundance of specific microbial taxa, including the Firmicutes-to-Bacteroidetes ratio, and potential pathogens.

Time frame: Within 24 hours before FMT intervention, and at 72 hours and 28 days after FMT initiation

Alterations in serum metabolites

Serum samples were collected for metabolomics analysis to comprehensively examine the composition and changes of endogenous small molecule metabolites in the blood.

Time frame: Within 24 hours before FMT intervention, and at 72 hours after FMT initiation

Change in the respiratory subscore of SOFA

Change in the respiratory subscore of SOFA from randomization (baseline) to 168 hours post-intervention

Time frame: Within 24 hours before FMT intervention, and on days 1, 2, 3, 4, 5, 6 and 7 after FMT initiation

Correlation between gut microbiota and pulmonary microecology

The results obtained from metagenomic and metabolomic analyses of rectal swabs and BALF were used to explore the relationship between the two

Time frame: Within 24 hours before FMT intervention, and at 72 hours after last FMT administration

Serum Citrulline

The determination of serum Citrulline is used as an indicator for evaluating intestinal barrier function.

Time frame: Within 24 hours before FMT intervention, and on days 1, 2, 3, 4, 5, 6 and 7 after FMT initiation

Changes of APACHE II score

The APACHE II scoring system serves as a critical tool for evaluating the clinical status and prognosis of ICU patients. This system comprises three components: the Acute Physiology Score (APS), the Age Score, and the Chronic Health Evaluation Score. The total score is derived by summing these three components. The theoretical maximum score is 71, with higher scores indicating more severe conditions. Notably, the APS encompasses 12 physiological parameters and introduces a formula for calculating the risk of death (R). By aggregating the R values of all patients and dividing by the total number of patients, the predicted mortality rate for the patient population can be estimated.

Time frame: Within 24 hours before FMT intervention, and on days 1-7 after inclusion

ICU mortality rate

Mortality rate in ICU

Time frame: From date of randomization until the date of discharge from the ICU or date of death from any cause during ICU stay, whichever came first, assessed up to 6 weeks

In-hospital mortality rate

Mortality rate during hospitalization

Time frame: From date of randomization until the date of discharge from the hospital or date of death from any cause during hospitalization, whichever came first, assessed up to 6 weeks

90-day all-cause mortality rate

The mortality rate within 90 days after inclusion in the study

Time frame: Within 90 days after inclusion

90-day post-discharge readmission rate

The proportion of patients readmitted within 90 days after discharge among those enrolled in the study

Time frame: Within 90 days after inclusion

Secondary pulmonary infection rate within 90 days of study enrollment

The incidence of secondary pulmonary infection within 90 days following study enrollment

Time frame: Within 90 days after inclusion

FMT for Lung and Associated-organ Rescue Efficacy in ARDS Patients

Overview

Conditions

Interventions

Eligibility

Locations (1)

Outcomes

Primary Outcomes

Secondary Outcomes

Central Contacts