A galactoglucan isolated from of Cistanche deserticola Y. C. Ma. and its bioactivity on intestinal bacteria strains

To understand whether polysaccharides may have impact on gut microbiota, a neutral polysaccharide CDA-0.05 with an average molecular weight of 7.96 kDa was obtained from Cistanche deserticola Y. C. Ma. The monosaccharide composition analysis indicated that CDA-0.05 was composed of glucose and galactose in a molar ratio of 96.4: 3.6. The backbone of CDA-0.05 contained 1, 4-linked α-D-Glcp, 1, 4, 6-linked α-D-Glcp and 1, 4-linked β-D-Galp, with branches of T-linked α-D-Glcp attached at C-6 of 1, 4, 6-linked α-D-Glcp residues. Bioactivity test results suggested that CDA-0.05 could promote the growth of three species of Bacteroides (B. thetaiotaomicron, B. ovatus and B. fragilis) significantly. Furthermore, CDA-0.05 could also promote some probiotics growth, such as Lactobacillus casei, Lactobacillus plantarum and Lactobacillus reuteri. These results suggested that CDA-0.05 might help to maintain intestinal homeostasis and could be recommended as part of fibers or drugs candidate to benefit human body by regulating gut bacteria.