Abstract
Increasing attention is being paid to the scientific evaluation of traditional Chinese medicine (TCM). As many TCMs are capable of biotransformation in the gastrointestinal tract, attention to biotransformation of TCM in the gastrointestinal tract may lead to discovery of the active components and active mechanisms. In this article, we review reports that host metabolic enzymes and intestinal bacteria may be responsible for the metabolism of TCM. Good understanding of the in vivo course of TCM will help us to know how to conduct metabolism evaluation of TCM by using in vitro human-derived system. This evaluation system will create new views on TCM as effective and safe therapeutic agents.