Impact of fecal microbiota transplantation on lung function and gut microbiome in an ARDS rat model: A multi-omics analysis including 16S rRNA sequencing, metabolomics, and transcriptomics.

Objective: Acute respiratory distress syndrome (ARDS) is a severe pulmonary condition characterized by inflammation and lung damage, frequently resulting in poor clinical outcomes. Recent studies suggest that the gut-lung axis, mediated by gut microbiota, is critical in ARDS progression. This study investigates the therapeutic potential of fecal microbiota transplantation (FMT) in an ARDS rat model (n = 6).

Introduction: The pathogenesis of ARDS involves complex interactions between the lungs and gut, with microbiota playing a key role. Understanding the effects of FMT on lung function and gut microbiota may provide new therapeutic strategies for ARDS management.

Methods: Sprague-Dawley rats were pre-treated with a broad-spectrum antibiotic cocktail to create a germ-free state and subsequently exposed to intranasal lipopolysaccharide to induce ARDS. The rats then received FMT treatment. Lung samples were analyzed using histopathology and transcriptomics. Fecal samples were analyzed using 16S rRNA sequencing and metabolomics.

Results: FMT treatment significantly reduced lung injury and improved pulmonary function, as evidenced by increased partial pressure of arterial oxygen (PaO₂) and decreased partial pressure of arterial carbon dioxide (PaCO₂). FMT also significantly altered in gut microbiota composition by regulating the gut microbiota composition of Akkermansia and Lactobacillus, restoring the abundance of genera such as Muribaculaceae, Clostridia_UCG-014, Prevotella, and Adlercreutzia, while reducing Romboutsia. FMT restored key metabolic pathways involved in lipid metabolism, amino acid biosynthesis, and immune regulation, including the modulation of immune pathways like mTOR signaling. These alterations contribute to reduced lung injury and improved pulmonary function.

Conclusion: These findings indicate that FMT may exert its beneficial effects in ARDS by modulating the gut microbiota and enhancing metabolic and immune responses. However, given that this study remains in the preclinical stage, further validation in clinical studies is necessary before considering clinical application.