Polygonatum odoratum polysaccharide ameliorates the allergic airway inflammation through regulating the gut microbiota and inhibiting gut-lung migration of ILC2s

Polygonatum odoratum is widely recognized to conribute to various health benefits, primarily attributed to its polysaccharide (POP). Polysaccharides are not directly and readily absorbed by the gastrointestinal system, but can interact with the gut microbes. This study aims to clarify the mechanism of POP in mitigating and preventing OVA-induced allergic airway inflammation via the gut-lung axis. The results showed that POP improved the symptoms associated with allergic respiratory responses, and the efficacy of POP was impeded due to the disruption of gut microbiota caused by antibiotics. The POP altered gut microbiota effectively alleviated the type 2 inflammation, reduced the number of ILC2s in the lung and gut, and inhibited the movement of intestinal ILC2s towards the lung. Clostridia UCG-014 and Rikenellaceae RC9 were figured out as pathogenic bacteria inhibited by POP. This study provides a reference for therapeutic application of POP in managing allergic airway inflammation via the gut-lung axis.