THE STATE AND SIGNIFICANCE OF GUT MICROBIOTA IN BREAST CANCER

This article reviews the structural and functional state of the gut microbiota in breast cancer patients, along with its diagnostic and prognostic significance, based on current literature. Given the rising incidence, including in Uzbekistan, and the inability of traditional risk factors to explain all cases, gut microbiota dysbiosis is discussed as a novel pathogenetic factor. Key dysbiotic changes – a decreased Firmicutes/Bacteroidetes ratio, reduced butyrate-producing Faecalibacterium prausnitzii and Bifidobacterium, and increased Fusobacterium nucleatum, Bacteroides fragilis, Escherichia coli – are analyzed in relation to molecular subtype and disease stage. The potential of using microbiota composition and metabolites (e.g., butyrate, kynurenine) as non-invasive biomarkers for early diagnosis, prognosis, and therapy response prediction is examined. Therapeutically, evidence on the efficacy of probiotics, prebiotics, and synbiotics in reducing chemotherapy-related diarrhea and fatigue, improving endocrine therapy out­comes by lowering β‑glucuronidase activity, and the use of fecal microbiota transplantation in immunotherapy-re­sistant cases is presented. The importance of a high-fiber diet and fermented foods in risk reduction through micro­biota modulation is also discussed. The need for systematic microbiota-based research in Uzbekistan is substantiated.