Anti-Aging Effects of Low-Molecular-Weight Polysaccharide Psp-1-1 from Steamed Polygonatum Sibiricum Via Gut Microbiota Modulation and Neuroprotective Mechanisms

The progressive aging of modern society has highlighted the urgent need to enhance healthy aging and mitigate aging-associated chronic conditions. This study focused on the structural characterization and anti-aging properties of a low-molecular-weight polysaccharide (PSP-1-1) derived from steamed Polygonatum sibiricum, known as "longevity grass." Through bioactivity-guided isolation and stepwise purification, PSP-1-1 with a molecular weight of 2.7 kDa was successfully obtained. Structural analysis revealed that PSP-1-1 primarily consists of a →4)-β-D-Galp-(1→galactan backbone. Using Caenorhabditis elegans as a model organism, PSP-1-1 demonstrated significant anti-aging effects by extending lifespan, improving healthspan metrics, and enhancing tolerance to stress. Moreover, PSP-1-1 alleviated β-amyloid and tau-induced neurotoxicity, preserved neuronal integrity, and improved locomotive functions in neurodegeneration models. PSP-1-1 treatment also modulated the gut microbiota, increasing the ratio of Firmicutes and enhancing the abundance of beneficial short-chain fatty acid (SCFA)-producing bacteria, such asLactobacilli. These findings underscore the potential of PSP-1-1 as a natural therapeutic agent for promoting healthy aging and preventing age-related diseases. PSP-1-1 offers promising applications in the development of anti-aging pharmaceuticals and functional foods, paving the way for future research and translational applications in health and wellness.