Study on the structural characteristics, in vitro hypoglycemic activity, and regulatory mechanisms of <i>Alpinia oxyphylla</i> polysaccharide in modulating human gut microbiota

作者：Junlin Wu, Jiayue Li, Fang Ma, Sijie Huang, X.Y. Ye, Min Yang, Hua Yang, Yunping Peng, S. Zhu, Meng Wang · 发表于：Italian Journal of Food Science · 年份：2026 · DOI：10.15586/ijfs.v38i2.3430 · 研究领域：Polysaccharides and Plant Cell Walls、Gut microbiota and health、Probiotics and Fermented Foods

This study aimed to systematically compare the structural characteristics, in vitro hypoglycemic activity, and regulatory effects on gut microbiota of Alpinia oxyphylla polysaccharides (AOFP) obtained by three extraction techniques, high-pressure and high-temperature (HH), acid-assisted high-pressure and high-temperature (AHP), and Aspergillus niger fermentation (ANF), to elucidate their structure–activity relationship and gut microbiota regulation mechanisms. By comparing the three types of AOFP (AOFP-HH, AOFP-AHP, AOFP-ANF), we revealed intrinsic associations among structure, activity, and microbiota regulation. The HH method promoted the ordered arrangement of β-1,3-glucan chains, forming a semicrystalline state and folded lamellar structures, thereby exhibiting the strongest hypoglycemic activity (α-amylase inhibition rate: 97.08 %; α-glucosidase inhibition rate: 59.43 %). The key mechanism lies in the synergy between the integrity of β-1,3-glycosidic bonds and the galacturonic acid content (11.74 %); together, they enhance activity through spatial hindrance effects and hydrogen bond networks. On the other hand, the AHP method, due to acid-induced cleavage of glycosidic bonds, generated amorphous low-molecular-weight structures (1.03 kDa), leading to a marked reduction in activity. The ANF method produced medium-molecular-weight fragments (1.14 kDa) via enzymatic hydrolysis. In terms of gut microbiota regulation, all AOFPs significantly promoted early butyrate production;...