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

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.