Breast cancer ranks among the most prevalent malignancies in women. Chemotherapy, a cornerstone of its multimodal treatment, frequently induces a spectrum of adverse effects, with cancer-related fatigue (CRF) being the most common and clinically impactful. Currently, the pathogenesis of CRF remains incompletely elucidated, and reliable diagnostic and therapeutic strategies are lacking. Impairment of intestinal barrier function is recognized as one of its key pathogenic mechanisms, while probiotics have been shown to alleviate fatigue symptoms by repairing the intestinal barrier and modulating immune-inflammatory responses. This review synthesizes the research progress regarding the role of probiotics in managing CRF in breast cancer patients undergoing postoperative chemotherapy, aiming to provide novel insights for clinical adjuvant therapy.