Comparative study of physicochemical and gut microbiota fermentation properties of fingered citron polysaccharides at...

Polysaccharides typically have broad-spectrum prebiotic properties that affect host health by regulating the intestinal microenvironment. The varying degrees of prebiotic effects of polysaccharides are determined by their structural characteristics. To comprehensively investigate the relationship between the structural differences and prebiotic properties of fingered citron polysaccharides (FCPs), FCP-W, FCP-N and FCP-C separately ultrasonic extracted by water, 0.05 M NaOH and 4 mM citric acid were characterized and fermented. Results showed that the three FCPs differed markedly in yield, surface morphology, monosaccharide composition, crystal structure and fermentation characteristics. FCP-W extraction had the advantage of simplicity, but unexpectedly promoted the enrichment of pathogenic g_Escherichia-Shigella. FCP-N possessed the highest extraction yield of 19.2% and the highest proportion of "smooth region", which significantly promotes the proliferation of Lachnospira and the accumulation of short-chain fatty acids (SCFAs) due to the abundant Fuc and Glu in its structure. FCP-C exhibits a honeycomb-like with sparse network structure and resulting in poor water-solubility. Correlation analysis indicated that the higher branching degree and RG-II content of FCP-C might be responsible for its enrichment effect on Bifidobacterium, Blautia and SCFAs. The above results suggested that FCP-N and FCP-C exert better prebiotic properties, and can serve as promising bioactive products in the functional food and medicine industries.