Bacteria and breast cancer
Bacteria are found living in breast tissue. Some of these bacteria may herald the onset or may even contribute to the development of breast cancer.
Bacteria can be found throughout the body. For women most live in the mouth, gut and vagina. A tiny population can also be found in breast tissue as well. The bacteria located in varying sites around the body can play a role in regulating immune function.
Changes in the bacteria can contribute to serious diseases including periodontitis in the mouth, inflammatory bowel disease, bacteria vaginitis and psoriasis. Given the presence of bacteria in breast tissue, researchers have started to ask whether changes in bacteria can alter breast cancer risk.
Using advanced sequencing technologies a Canadian research team examined the bacteria found in breast tissue from women with benign tumours, cancerous tumours and from healthy breast tissue. The tissues were sourced from women already undergoing breast surgery for either cancer therapy or breast augmentation.
The researchers found differences in the types of bacteria living in the breast tissue of healthy and diseased tissue. Women with tumours had higher levels of three types of bacteria; Enterobacteriaceae, Staphylococcus and Bacillus.
This research doesn’t show that the bacteria are causing the cancer, but rather that these alterations in the bacteria population are always present in the case of cancer. There is the possibility that these bacteria can cause cancer by damaging the DNA of breast tissue. Although, the researchers also suggest that the stress and damage caused by the already growing cancer could suppress the immune system. This would allow the opportunistic bacteria to take hold and grow.
Almost 1 in 8 women will experience breast cancer at some stage over their life. Several well-known genes increase the risk, as does becoming overweight or obese. But for the majority of women it is early detection of early signs of tumours that is still the best strategy.
Understanding whether bacteria found within the breast tissue a can be used as another early risk factor is an intriguing area of research.
A test of the bacteria may provide a better early warning system, before the development of any cancerous tissue. It’s also yet to be established if the bacteria actually contribute to the development of the cancer.
If this is the case, then future strategies to reduce the risk of breast cancer may include probiotics to encourage the growth of health bacteria or selective antibiotics to kill the dangerous bacteria.
Till then, the best way to feed the healthy bacteria is by consuming a diet rich in prebiotics, including fruits, vegetables, grains and cereals. Probiotics can also help restore bacterial balance, and foods containing a healthy variety of probiotic bacteria may also help.
Last Reviewed: 01/11/2019
Norman Swan Medical Communications
Urnamiak C et al. The microbiota of breast tissue and its association with tumours. Applied and Environmental Microbiology Epub online June 24, 2016. doi: 10.1128/AEM.01235-16.