Bletilla striata polysaccharide alleviates chronic obstructive pulmonary disease via modulating gut microbiota and NR1H4 expression in mice

• Published in: Microbial pathogenesis 2024-08, Vol.193, p.106767, Article 106767
• Main Authors: Li, Liang, Li, Zhaoguo, Peng, Yuqiu, Fu, Yunli, Zhang, Ranzhi, Wen, Jiexiang, Wang, Jie
• Format: Article
• Language: English
• Subjects: Animals; Bacteroides - drug effects; Bletilla striata polysaccharide; Chronic obstructive pulmonary disease; Disease Models, Animal; Epithelial Cells - drug effects; Epithelial Cells - metabolism; Gastrointestinal Microbiome - drug effects; Gut microbiota; Humans; Inflammation; Inflammatory response; Lung - drug effects; Lung - microbiology; Lung - pathology; Male; Mice; Mice, Inbred C57BL; NR1H4; Orchidaceae - chemistry; Oxidative Stress - drug effects; Polysaccharides - pharmacology; Pulmonary Disease, Chronic Obstructive - drug therapy; Pulmonary Disease, Chronic Obstructive - metabolism; Pulmonary Disease, Chronic Obstructive - microbiology; RNA, Ribosomal, 16S - genetics; Smoke - adverse effects
• ISSN: 0882-4010; 1096-1208; 1096-1208
• DOI: 10.1016/j.micpath.2024.106767

Bletilla striata polysaccharide (BSP) is the main component of Bletilla striata and has been revealed to enhance immune responses. Chronic obstructive pulmonary disease (COPD) results from the chronic inhalation of toxic particles and gases, which initiates innate and adaptive immune responses in the lungs. This study aimed to evaluate whether the effects of BSP on COPD were related to the abundance of gut microbiota and explored the underlying mechanism. COPD mice were induced with cigarette smoke and human bronchial epithelial cells (HBEC) were subjected to cigarette smoke extract (CSE) for in vitro studies. BSP alleviated the inflammatory response and the inflammatory cell infiltration in lung tissues and promoted the recovery of respiratory function in COPD mice. BSP mitigated CSE-induced HBEC injury by repressing inflammation and oxidative stress. 16s rRNA sequencing revealed that BSP increased the abundance of Bacteroides intestinalis. Bacteroides intestinalis colonization enhanced the therapeutic effect of BSP in COPD mice by upregulating NR1H4 and its encoded protein FXR. Reduction of NR1H4 impaired the therapeutic impact of BSP and Bacteroides intestinalis in COPD. These data demonstrate that BSP inhibits COPD by upregulating NR1H4 through Bacteroides intestinalis, which underpins the application of BSP as a therapeutic agent for COPD. •BSP alleviates inflammatory response and immune cell infiltration in COPD mice.•BSP alleviates respiratory function and oxidative stress in COPD mice.•BSP affects the abundance of gut microbiota in COPD mice.•Bacteroides intestinalis colonization enhances the therapeutic effect of BSP on COPD.•Bacteroides intestinalis mitigates COPD by regulating NR1H4 expression.