The Effect of Dioscoreae Rhizoma on Gastrointestinal Function: A Systematic Review

Background/Objectives: Dioscoreae Rhizoma, commonly known as yam, has long been used in East Asia as a medicinal food for gastrointestinal (GI) health. This systematic review aimed to assess the GI-related benefits of Dioscoreae Rhizoma by synthesizing findings from both human clinical trials and in vivo experimental studies. Methods: A structured search of eight major databases—including PubMed, EMBASE, and Web of Science—was conducted through April 2025. This systematic review includes both human and in vivo animal studies that investigated the effects of Dioscoreae Rhizoma on gastrointestinal function. Studies such as in vitro experiments, non-original articles and studies involving multi-herbal formulations were excluded. Risk of bias was assessed with three different tools including the Cochrane Risk of Bias 2 (RoB 2) tool. Results: Twenty-seven studies met the inclusion criteria, comprising two human trials and twenty-five animal experiments. Clinical trials reported improvements in gut-microbiota balance, glycemic control, and postsurgical recovery, including enhanced wound healing and reduced infection rates. In animal models, yam-derived interventions attenuated inflammatory responses, enhanced antioxidant defenses, preserved mucosal-barrier integrity, and favorably modified gut-microbiota composition. Discussion and Conclusions: Accumulating evidence supports the GI-beneficial effects of Dioscoreae Rhizoma, mediated through diverse biological pathways, including immunomodulation, antioxidation, and microbiota regulation. This study has limitations on lack of high-quality human studies, small sample size and heterogeneity among studies regarding different plant parts used, extraction processes, and dosage. Further rigorously designed studies are warranted to clarify the mechanisms, standardize intervention protocols, and validate clinical efficacy.