Commensal Dysbiosis Alters Primary Bile Acid Signaling to Drive Mammary Gland Inflammation and Breast Tumor Dissemination.

Commensal dysbiosis increases primary bile acids by elevated primary BAs in gut microbiome, driving HR+ breast cancer metastasis via PGE2 signaling.

• Why it matters: Understanding how gut microbiome imbalances influence breast cancer progression can reveal new therapeutic targets and improve patient outcomes, especially for metastatic HR+ tumors.
• What they did: The study used metabolomic profiling, sequestration, and supplementation approaches to show that dysbiosis elevates primary BAs, which promote tumor dissemination through PGE2 pathways, and analyzed patient data correlating BA signatures with survival.
• The result: Findings suggest that restoring microbial BA metabolism or targeting PGE2 signaling may reduce metastasis, with bile acid sequestrants linked to longer survival in metastatic breast cancer patients.