Anti-Obesity Effects Exerted by Achyranthes bidentata Polysaccharides in Diet-Induced Obese Mice

Obesity involves persistent inflammation, insulin resistance, and disturbances in gut microbiota. Achyranthes bidentata, a plant long used in Chinese medicine, contains polysaccharides with bioactive properties. This study investigates polysaccharides isolated from its water extract (ABPs) consisting of 41.83% Glucose, 40.75% Galacturonic Acid, 7.86% Arabinose, 6.11% Galactose and 3.45% Rhamnose, which were prepared. We showed that ABPs mitigated obesity, decreased insulin resistance, alleviated inflammation, and relieved hepatic damage in high-fat diet (HFD)-fed mice. Specifically, ABPs regulated glucose levels by downregulating GLUT1 and upregulating PGC-1α, and significantly reduced the expression of key genes related to adipogenesis and metabolism (PPARα, PPARγ, C/EBPα, and SOX4) in obese mice. Subsequent studies revealed that ABPs could alter the gut microbiota profile and increase short-chain fatty acids (SCFAs) levels in mice on an HFD. Treatment with ABPs reduced the Firmicutes: Bacteroidota ratio and declined the abundances of intestinal bacteria including Intestinimonas, Lachnospiraceae_unclassified and Oscillibacter. ABPs supplementation significantly restored the diet-induced imbalance of SCFAs in HFD-fed mice, notably reversing the reduction in propionic acid. This suggests that ABPs exert obvious anti-obesity activities, by suppressing systematic inflammation, improving hepatic metabolism, while concurrently ameliorating gut microbiota dysregulation in obese mice.