The Microbiota of Breast Tissue and Its Association with Tumors

Authors: Urbaniak, C. et. al.

Source: Appl Environ Microbiol doi:10.1128/AEM.01235-16

aem.asm.org/content/82/16/5039.full

These researchers had already established that breast tissue contains specific bacteria (a microbiome). Just as bacteria appear to play a role in colon and other cancers, the group investigated possible connections between breast bacteria and malignancy.

71 women undergoing breast surgery in a single hospital consented to donating specimens for the study. There was fairly even distribution between cancer and non-cancer diagnoses. For women with breast cancer, the tissue sample was taken about 5 centimeters away from the tumor. The tissue samples were evaluated for breast and bacterial DNA. The bacterial DNA was identified and expanded within a second cell line.

Compared to women without breast cancer, women with the disease had higher cell levels of Bacillus, Staphylococcus, Enterobacteriaceae, Comamondaceae and Bacteroides. Interestingly, women with benign breast tumors had tissue levels of bacteria similar to those of breast cancer patients.

Women with no breast tumors (cancer or benign) had higher levels of Prevotella, Micrococcus, Lactococcus, and Streptococcus. The team noted that these last two bacteria have demonstrated anticarcinogenic (preventing cancer development) properties in other studies.

The results of this study raise questions about the role that the microbiome plays in breast cancer development and provides opportunities to explore ways to treat and prevent the disease.