Qingxuan Zhike Granules Modulate Gut Dysbiosis and Enhance Intestinal Repair in Murine Mycoplasma pneumonia

This study aimed to investigate the therapeutic efficacy and underlying mechanisms of Qingxuan Zhike Granules (QXZKG) in pediatric Mycoplasma pneumoniae pneumonia (MPP), with a specific focus on its roles in modulating gut microbiota and promoting intestinal repair via the "gut-lung axis". A BALB/c mouse model of MPP was established for in-vivo experiments. Evaluations included the disease activity index (DAI), histopathological assessment of lung and intestinal tissues (H&E staining), pro-inflammatory factor levels (PCR), intestinal tight junction protein expression (Western blot), gut microbiota composition (16S rDNA sequencing), and serum lipopolysaccharide (LPS) levels. For in-vitro experiments, a Caco-2/RAW264.7 co-culture system was used to assess the effects of drug-containing serum on cell viability, apoptosis, inflammatory factor production, and barrier protein expression. QXZKG administration dose-dependently improved the DAI and body weight loss in MPP mice. It significantly alleviated pathological damage in both lung and intestinal tissues, reduced the expression of pro-inflammatory factors, and up-regulated the levels of intestinal tight junction proteins. Concurrently, QXZKG decreased serum LPS concentrations, restored gut microbiota diversity, and modulated its composition by increasing probiotic abundance and reducing opportunistic pathogens. In-vitro experiments confirmed that QXZKG-containing serum enhanced cell viability, inhibited apoptosis, reduced LPS levels, and up-regulated barrier protein expression. QXZKG is associated with modulation of the gut microbiota, enhancement of intestinal barrier function, and suppression of systemic inflammation, suggesting a potential involvement of the "gut-lung axis". These findings provide experimental evidence for the expanded clinical application of QXZKG.