Fecal Microbiota Transplantation Modulates Th17/Treg Balance via JAK/STAT Pathway in ARDS Rats

This study evaluated the therapeutic effects of fecal microbiota transplantation (FMT) on lipopolysaccharide (LPS)-induced acute respiratory distress syndrome (ARDS) in rats. The study focused on the balance of T-helper 17 (Th17) and regulatory T (Treg) cells, as well as the modulation of the JAK/STAT pathway. This study established a rat ARDS model using intranasal LPS instillation, administering interventions such as FMT, Treg cell depletion, and JAK inhibitors. Assessments included histopathological examination of lung and intestinal tissues, flow cytometry for Th17 and Treg cell proportions, qPCR and Western blot for gene and protein expression, ELISA for inflammatory cytokines, and correlation analysis using Spearman's method for cytokine-immune cell interactions. Results indicated that FMT and JAK inhibitors significantly reduce lung damage induced by LPS, reduced alveolar destruction and inflammation, restored Th17/Treg balance, and inhibited JAK/STAT pathway activity. Notably, FMT decreased pro-inflammatory cytokines (IL-2, IL-6, IL-8, IL-17A, IL-23, TGF-β1) and increased anti-inflammatory cytokines (IL-10, IL-35) in serum. Spearman correlation analysis indicated that FMT restored immune balance by modulating the interactions between cytokines and immune cells. In conclusion, FMT effectively alleviates lung and intestinal injury in LPS-induced ARDS rat models by modulating Th17/Treg balance and inhibiting JAK/STAT pathway activity, demonstrating promising therapeutic potential for ARDS treatment.