Scientists at Johns Hopkins discovered a surprising link between a gum‑disease germ and breast cancer. The germ, called Fusobacterium nucleatum, can travel through the blood and settle in breast tissue.
How the Germ Affects Breast Cells
When the germ reaches the breast, it creates inflammation and damages DNA. The damage triggers cells to grow too fast and become more aggressive. In mouse experiments, tumors grew larger and spread to the lungs faster when the germ was present.
DNA Repair Mistakes Help Cancer Grow
The germ harms DNA and then forces the cell to repair it. One repair method, called non‑homologous end joining, works quickly but often makes mistakes, leading to new mutations. Even a short exposure raised the amount of a protein named PKcs, which made cancer cells move, invade, act like stem cells, and resist chemotherapy.
BRCA1‑Mutated Cells Are Extra Vulnerable
Breast cells with a BRCA1 mutation took up more of the germ because they have extra sugar molecules on their surface. These cells kept the germ for many generations, which increased DNA damage and made the cancer behave more aggressively.
What This Means for Everyday Life
The study suggests that keeping your mouth clean might lower the risk of breast cancer, especially for people who carry BRCA1 mutations. More research is needed to see how oral care can be used in cancer prevention.
The research was funded by several cancer‑focused foundations and government programs.