Change in chemical composition and enhancement of intestinal microflora of acid hydrolyzed polysaccharides from Zizyphus jujube and Sterculia lychnophora

The homology between food and medicine has been a successful and well-accepted concept in traditional medicine, where people believe that beneficial naturally available substances can be replenished via diet to promote health. In this study, the polysaccharides in jujube fruit (Ziziphus jujuba Mill.) and dried boat-fruited Sterculia seeds (Sterculia lychnophora) were extracted using different methods (water, acid, and alkaline extraction), and their physicochemical properties and compositions were investigated. Additionally, the effects of polysaccharides on the growth of known intestinal bacteria were investigated using in vitro incubation. The results showed that the acid and alkaline extraction methods resulted in the highest yields of polysaccharides with a high uronic acid content and satisfactory antioxidant activity. The water-extracted polysaccharides exhibited a suitable viscosity. Moreover, the water-extracted polysaccharides were acid-hydrolyzed for 2- 6 h, followed by gel permeation chromatography (GPC) to obtain acidic hydrolyzed polysaccharides with a wide range of molecular weights and high carbohydrate contents. Subsequently, five known strains of intestinal bacteria cultured with the acidic hydrolyzed polysaccharides from jujube fruits and pandahai (10 mg/mL) were found to proliferate in Bifidobacterium bifidum, Bifidobacterium longum, Lactobacillus delbrueckii, and Propionibacterium freudenreichir in 0- 48 h cultures. However, further evidence is required to validate these results, either in gastrointestinal simulations or animal models.