Simulated digestion and in vitro fermentation of a polysaccharide from lotus (Nelumbo nucifera Gaertn.) root residue by the human gut microbiota

•Lotus root polysaccharide (LRP) could be partially degraded during simulated digestion in vitro.•LRP could be degraded and utilized by gut microbiota.•LRP could decrease intestinal pH and promote the production of short-chain fatty acids.•LRP improved the structure and composition of gut microbiota.