Abstract: Polysaccharide drugs are a type of safe and effective natural drug with a wide range of pharmacological activity such as anti-tumor, immunomodulation, and oxidation, and polysaccharide drugs are currently more concerned. However, since the molecular weight of the polysaccharide is quite large, most of which do not have ultraviolet absorption and fluorescent groups, which makes the qualitative and quantitative analysis of polysaccharides are relatively difficult. In addition, endogenous sugar substances may also cause certain interference to polysaccharide assay in biological samples, and therefore, in vivo metabolism and PK/PD key technologies in polysaccharide drugs have been research hotspots. This paper summarizes the relevant literature published in recent years, reviewing the biological activity and pharmacokinetics of polysaccharide drugs, proposing gut bacteria may be potential "organ" affecting metabolism and efficacy of polysaccharide drugs, and providing thoughts on gut bacteria mediating polysaccharide drugs in vivo and key technology research of PK/PD, in order to provide more scientific ideas for pharmacokinetics, pharmacological research and molecular mechanisms of polysaccharide drugs.

Key words: polysaccharide drugs, biological activity, pharmacokinetic characteristics, PK/PD, gut bacteria