Simulated digestion and fermentation in vitro by human gut microbiota of polysaccharides from Helicteres angustifolia L.

Helicteres angustifolia L. is a familiar herbal plant, which exhibits various bioactivities with potential benefits for human health. In this study, the simulated digestion (saliva, simulated gastric and small intestinal conditions) and fermentation in vitro of polysaccharides from H. angustifolia L. (HaLPs) were evaluated, and the effects of HaLPs on gut microbiota were examined using high-throughput sequencing technology. The results indicated that the simulated gastrointestinal digestion had no effect on HaLPs, so HaLPs could reach the large intestine safely. However, the molecular weight of HaLPs and the reducing sugar decreased significantly after fermentation under anaerobic conditions. It was found that HaLPs had the significantly alternation effect on the composition of the gut microbiota. Furthermore, the total short-chain fatty acids content increased significantly after fermentation (from 2.25 ± 0.13 mM to 22.45 ± 4.56 mM). These results provided an understanding of the digestive characteristics of HaLPs and afforded a viable basis for their development.