Investigating postbiotics as innovative adjuvants: deciphering the gut-breast connection in breast Cancer therapy, from gut microbiome to personalized medicine.

Breast cancer is the most common and deadly cancer affecting women globally. While traditional treatments - surgery, chemotherapeutic agents, radiotherapy - are used, factors damage their effectiveness: tumor heterogeneity, drug resistance, and non-targeted actions on cancer cells. Postbiotics, a newer category of biotics, confer benefits without living microorganisms and show promise against cancer. This review summarizes the link between gut microbiota and BC, postbiotic mechanisms against cancer, and their potential for personalized medicine. Postbiotics modulate the host immune system and inflammation in BC management. They target apoptotic signaling pathways, such as mitochondrial-dependent and death receptor-dependent pathways, interrupt the cell cycle, inhibit cancer cell growth, and regulate immune responses. In cancer, integrative approaches for therapies include microbiome analysis to provide personalized medical treatment, highlighting the microbiome's impact on cancer. Compared to probiotics, postbiotics have advantages, including better bioavailability, stability, and safety profiles. However, research should continue to address clinical evidence and extended studies in their production and application. The use of postbiotics as adjunctive agents in BC treatment has been highlighted for their potential to enhance standard therapy outcomes.