Effects of Probiotics on Chemotherapy-induced Diarrhea

Chemotherapy-induced diarrhea (CID) is a common adverse event in cancer patients, which, unless treated, may lead to drug discontinuation and treatment failure. Some probiotics such as Lactobacillus, Bifidobacterium, and Saccharomyces species have been gaining clinical attention in alleviating chemotherapy-induced adverse events including diarrhea. This comprehensive review provides an overview and discusses preventive approaches of probiotics with respect to CID in several types of cancers. The potential mechanisms of probiotics may comprise regulation of intestinal microbiota, modulation of immune functions, or reduction of proinflammatory cytokines. The efficacy and safety precautions of probiotics in immunocompromised cancer patients are discussed. The non-pharmacological strategy using probiotics could reduce the use of anti-diarrheal or antibiotic agents. Some individuals experienced shorter length of hospital stay, better gastrointestinal function, and reduced incidence of chemotherapy dose reduction after probiotic administration. Nonetheless, some studies failed to report the benefits of probiotics in certain patients. This review also highlights preventive protocols and therapeutic implications by considering the potential influencing factors, particularly types of probiotic strains, dosages of probiotics, duration of their administration, patients' tolerability, and variations in probiotic effects over the cancer stages.