BACKGROUND: Fluoropyrimidines and irinotecan cause diarrhea, which can be particularly severe in some cases. Probiotic supplementation is a potential option for managing chemotherapy-induced diarrhea. This study aims to evaluate the efficacy and safety of probiotics in managing diarrhea induced by fluoropyrimidine or irinotecan-based chemotherapy in cancer patients. METHODS: A literature search was conducted in Cochrane Library, PubMed, ScienceDirect, SciFinder, and Scopus in August 2023. Observational and prospective studies of cancer patients receiving 5-fluorouracil, capecitabine, or irinotecan were included. RevMan (version 5.4.1) was used for statistical analysis. The study protocol was registered in PROSPERO. RESULTS: Of the 9400 records, 24 and 14 studies were included in the systematic review and meta-analysis, respectively. Most studies provided a combination of probiotic strains to patients from the initiation to the completion of chemotherapy cycles. Probiotic supplementation significantly reduced all grade diarrhea (RR = 0.40
95 % CI: 0.27, 0.60
P <
0.00001, I CONCLUSIONS: Probiotic supplementation is a promising option to manage chemoradiotherapy-induced diarrhea without serious side effects in cancer patients receiving fluoropyrimidines or irinotecan-based regimens. Given the clinically meaningful ARR and favorable NNT values, probiotics may have a role in clinical practice. However, larger trials are needed to standardize probiotic strain, dosage, duration, and target patient subgroups. SYSTEMATIC REVIEW REGISTRATION: PROSPERO database (CRD42023473324).