The gut microbiome has been shown to influence numerous biological processes and may even lead to the development of certain diseases.
 
Prior research shows that bariatric surgery can impact the intestinal microbiome, which calls into question how the breast microbiome is affected by surgery, especially for patients at risk of developing breast cancer.
 
This issue is of particular interest because many high-risk women choose to undergo prophylactic mastectomy in an effort to prevent cancer, according to an article published by Microbial Sciences.
 
An imbalance of bacteria may also be associated with cancer recurrence and endotoxins, such as TNF, have been linked to metastatic breast cancer. These factors have led researchers to believe that the breast microbiome can play a role in cancer risk and recurrence, according to the article.
 
Previous research has indicated that breast microbiome health may vary based on geographic location. In Canadian women, the most common bacteria were Bacillus, Acinetobacter, and Enterobacteriaceae, while common bacteria in the breast microbiome of Irish women include Enterobacteriaceae, Staphylococcus, and Listeria welshmeri.
 
Interestingly, women with breast cancer have been found to have a higher prevalence of Enterobacteriaceae, Staphylococcus, and Bacillus compared with women without the disease.
 
Further studies that examine the breast microbiomes of healthy patients and those with cancer may increase the understanding of cancer development and lead to novel treatments, according to the article.
 
In a podcast, investigators from the University of California San Francisco (UCSF) discussed how Lactobacillus acidophilus—a probiotic found in yogurt—can have anti-cancer effects on the mammary gland, suggesting that patients may experience beneficial effects from consuming the bacteria, according to the article.
 
Additionally, Lactobacillus and Lactococcus spp. are common in healthy breast tissue and are thought to play a role in breast cancer prevention. Lactobacillus increases immune response and reduces several inflammatory markers.
 
The authors wrote that UCSF researchers have also suggested that probiotics may prevent post-surgical infections among patients who are undergoing a mastectomy or surgery; however, the effects have not been examined thoroughly.
 
Probiotics have also been observed to reduce Escherichia coli and increase Bifidobacterium, a beneficial gut bacterium. The association between gut and breast microbiomes have significant impact on breastfeeding. Other studies suggest that the gut microbiome of a breastfeeding mother has an important role in the immune function of an infant.
 
Much is known about breast milk microbiome, but each site within the tissue has a unique signature that may affect cancer, according to the article.
 
While additional studies are necessary to further explore the link between breast microbiome and cancer, probiotics may hold the key to improving both the gut and breast microbiomes, according to the article.