Structural-functional relationship of soluble dietary Fiber from Ganoderma lucidum-fermented sweet potato residue and its regulatory effects on gut microbiota.

Metadata-grounded summary

Citation abstract

Sweet potato residue (SPR), a by-product of sweet potato processing, is rich in dietary fiber and other is rich in dietary fiber and other essential nutrients; however, its industrial utilization remains limited. In this study, Ganoderma lucidum fermentation was employed to modify the soluble dietary fiber (SDF-F) from SPR, with a comprehensive analysis of its structural changes, functional activities, and potential effects on gut microbiota. Fermentation markedly altered the microstructure of SDF, increasing its porosity, reducing its molecular weight from 61.79 kDa to 17.72 kDa, and increasing the monosaccharide composition with four additional types. Functionally, SDF-F exhibited dual metabolic regulatory effects: it significantly enhanced lipid- and glucose-lowering capacities and promoted short-chain fatty acid production (286.06 mM/L). Moreover, SDF-F improved gut microbiota composition by increasing the relative abundance of beneficial Bacteroidetes (39 %) and reducing Proteobacteria (by 48 %). These microbial changes were associated with enhanced mucosal barrier function and immunomodulatory potential. By linking structural modifications to biological effects, this study offers a sustainable strategy for valorizing agricultural by-products into multifunctional food additives, supporting both circular bioeconomy initiatives and preventive nutrition.