Astragalus polysaccharides restore neutrophil functions and gut microbiota homeostasis in dairy cows with subclinical ketosis

作者：Shang Jiang, Li Na, Ke Zhang, Kexin Wang, Zhiyong Li, Yiqi Zhang, Yan Ren, Chao Wang, Xiancheng Feng, Yuchen Yang, Chenxi Xue, Jun Chen, Xiliang Du, Lin Lei, Wenwen Gao, Guowen Liu, Yuxiang Song, Xinwei Li · 发表于：Journal of Dairy Science · 年份：2025 · DOI：10.3168/jds.2025-26901 · 被引用次数：3 · 研究领域：Gut microbiota and health、Milk Quality and Mastitis in Dairy Cows、Probiotics and Fermented Foods

Subclinical ketosis (SCK) in periparturient cows is associated with gut microbiota dysbiosis and energy metabolism disorders. Although in vitro studies show that free fatty acids (FFA) and BHB impair polymorphonuclear neutrophil (PMN) functions-potentially causing secondary infections-limited in vivo evidence exists. Astragalus polysaccharides (APS) modulate metabolism, immunity, and gut microbiota, but their effects on PMN functions and gut microbiota in SCK cows remain unclear. This study aims to evaluate PMN dysfunction and gut microbiota dysbiosis in SCK cows, and clarify the protective effects of APS on these parameters. Multiparous cows were classified into healthy (CON; n = 40) and SCK (n = 38) groups based on serum BHB levels. Compared with CON cows, SCK cows exhibited reduced feed intake, negative energy balance (NEB), and dysfunctional PMN activation-characterized by inhibited phagocytosis and neutrophil extracellular traps (NET), along with enhanced respiratory burst and degranulation. Supplementation with APS restored PMN functional balance (increasing phagocytosis while reducing respiratory burst and degranulation) and alleviated NEB. Subclinical ketosis decreased gut microbiota α- and β-diversity without altering dominant phyla. At the genus level, SCK reduced Monoglobus, Faecalibacterium, Ruminococcus (short-chain fatty acid [SCFA]-producers), and increased Prevotella and Parabacteroides. Astragalus polysaccharides reversed these changes. Serum FFA and BHB nega...