Summary of best evidence for nutritional and dietary interventions in managing chemotherapy-induced gastrointestinal toxicity in cancer patients.

[BACKGROUND] Chemotherapy-induced gastrointestinal toxicity (CIGT) is one of the most frequent and debilitating adverse effects of cancer treatment, leading to impaired quality of life, malnutrition, treatment interruptions, and increased health care burden. Nutritional and dietary interventions have been recognized as essential strategies for the prevention and management of CIGT.

[OBJECTIVE] This study aims to provide an evidence-based foundation for clinical practice by systematically searching, evaluating, and summarizing the best available evidence on nutritional and dietary interventions for the prevention and management CIGT in cancer patients.

[METHODS] Following the "6S" evidence resource model, a top-down retrieval strategy was used to search relevant guidelines, best practices, evidence summaries, systematic reviews (SRs), and randomized controlled trials (RCTs) published between October 2014 and October 2025. Two reviewers independently screened, appraised, and extracted data. Evidence quality was graded using the Joanna Briggs Institute (JBI) system.

[RESULTS] A total of 25 publications were included, comprising 2 guidelines, 3 clinical decisions, 2 expert consensus, 14 SRs, and 4 RCTs. Through induction and synthesis, 30 best evidence items were identified and summarized into 6 thematic domains: general principles, management of general gastrointestinal side effects, alleviation of chemotherapy-induced nausea and vomiting, alleviation of intestinal mucositis, alleviation of diarrhea, and nutritional education and support.

[CONCLUSION] This study summarized the best evidence for nutritional and dietary interventions for the prevention and management of CIGT from six aspects, providing a scientific basis for health care professionals to design and implement nutritional care strategies that improve treatment tolerance, enhance nutritional status, and optimize patient outcomes. Local adaptation of these recommendations is encouraged, considering individual patient characteristics, clinical settings, and health care resources to ensure effective implementation.