苍术多糖通过肠道菌群重塑和色氨酸代谢保护金黄色葡萄球菌肺损伤

Abstract

Gut microbiota and their metabolites may shape pulmonary immune responses and infection progression. Plant-derived polysaccharides, such as Atractylodes lancea polysaccharides, have shown prebiotic activity, yet their protective mechanisms in pneumonia remain unclear. Here, A. lancea polysaccharides (ALPs), a water-soluble acidic fraction mainly composed of arabinose, galacturonic acid, glucose, and galactose with a predominant molecular weight of 3.52 kDa, were evaluated in a murine model of Staphylococcus aureus-induced lung injury. Oral pretreatment with ALP (100 or 400 mg/kg) alleviated lung injury, improved intestinal barrier integrity, reshaped the gut microbiota by enriching Limosilactobacillus, restored tryptophan-related metabolites, increased AhR expression in the lung and colon, and reduced inflammatory responses. Broad-spectrum antibiotic treatment markedly blunted the effects. Collectively, ALP protected against S. aureus-induced lung injury in association with gut microbiota remodeling, improved barrier integrity, and restored tryptophan metabolism along the gut-lung axis.