In vitro digestibility and prebiotic potential of a novel polysaccharide from Rosa roxburghii Tratt fruit

In the present study, the digestion properties of a polysaccharide from Rosa roxburghii fruit (RTFP-3) under saliva, simulated gastric and small intestinal conditions were studied for the first time. The results indicated that human saliva had no effect on RTFP-3. RTFP-3 was slightly degraded in simulated gastric and small intestinal juices. The molecular weight (Mw) of RTFP-3 was decreased from 67.59 to 44.22 kDa. Meanwhile, the reducing sugars were increased from 0.503 to 1.744 mM. Then, the prebiotic effects of RTFP-3 were examined by in vitro fermentation model. RTFP-3 could significantly increase the production of total short-chain fatty acids from 23.49 to 44.29 mM, and 60.28% of total carbohydrate was consumed after 48 h fermentation. Furthermore, RTFP-3 could significantly modulate the microbial structure by lowering the ratio of Firmicutes to Bacteroidetes from 14.89 to 4.68 after 48 h fermentation, and improving the relative abundances of some beneficial gut microbiota.