Structural Characterization and Gut Microbiota Modulation of CDP-2 Polysaccharide Extracted from Cistanche deserticola Ma

Cistanche deserticola Ma (CD) has historically been recognized for its dual role as a culinary and therapeutic parasitic herb, offering noteworthy medicinal and nutritional properties. Polysaccharides extracted and purified from CD have received an increasing great quantity of research attention due to their various pharmacological activities. In this study, using ultrasound combined with complex enzyme extraction, ethanol precipitation, DEAE-cellulose column (26 mm × 400 mm) chromatography, and Sephacryl S-400 HR column (26 mm × 1000 mm) chromatography, the heteropolysaccharides polysaccharide, named CDP-2, was separated and purified from the CDP. CDP-2 was a molecular weight of 65.60 kDa and consisted of Ara, Gal, Glc, Rha, Xyl, Man, Fuc, Gal-UA, Glc-UA, Man-UA, Gul-UA at a molar ratio of 39.05 : 23.17 : 16.29 : 11.10 : 1.79 : 1.22 : 0.47 : 3.28 : 2.48 : 0.62 : 0.55. The backbones of CDP-2 contained ⟶4)-α-D-Glcp-(1⟶, ⟶3,6)-β-D-Galp-(1⟶, and ⟶5)-α-L-Araf-(1⟶, with a minor component of ⟶3)-β-D-Galp-(1⟶. The side chains are mainly formed by α-L-Araf-(1⟶ or α-L-Rhap-(1⟶ linked to the O-6 position of residue ⟶3,6)-β-D-Galp-(1⟶. Biological assays revealed CDP-2’s efficacy in augmenting the proliferation of specific Bacteroides strains. Additionally, it was observed to facilitate the production of short-chain fatty acids by these bacterial strains. Cumulatively, these insights underscore the CDP-2’s prospective role in bolstering gastrointestinal health via fostering Bacteroides colonization.