Does bacteria play a role in breast cancer?

Researchers have found that women with breast tumours had a different mix of bacteria living in their breast tissue when compared to women who did not have tumours, reported Science Daily.

The study by Cleveland Clinic researchers discovered that healthy breast tissue contained more of the bacteria Methylobacterium.

Researchers are studying how bacteria may stave off breast cancer. (Photo: Kaboompics/Pixabay)

"To my knowledge, this is the first study to examine both breast tissue and distant sites of the body for bacterial differences in breast cancer," said co-senior author Professor Charis Eng, chair of Cleveland Clinic's Genomic Medicine Institute and director of the Center for Personalized Genetic Healthcare, in Science Daily.

To date, most research has focused on the gut microbiome - bacteria that live in the digestive tract – and how they influence many diseases. This finding confirmed what researchers had long suspected about the microbiome in breast tissue and how it plays a role in breast cancer.

"Our hope is to find a biomarker that would help us diagnose breast cancer quickly and easily. [We] hope we can use microbiomics right before breast cancer forms and then prevent cancer with probiotics or antibiotics,” said Prof Eng.

The study examined the breast tissues of 78 patients who underwent mastectomy as well as their oral rinses and urine to determine the bacterial composition of these distant sites in the body, according to Science Daily.

Apart from Methylobacterium, the team also found increased levels of three bacteria - Enterobacteriaceae, Staphylococcus and Bacillus – in their urine samples, according to Live Science, a website that publishes health and science updates.

E. coli, which is a type of Enterobacteriaceae, was more common in the breasts of women with tumours.

When the bacteria from the tumour tissues were added to human breast cells in lab dishes, Enterobacteriaceae and Staphylococcus were found to damage DNA, which can lead to cancer, wrote the researchers.

Gregor Reid, a professor of microbiology and immunology at Western University in Ontario, and the senior author of the study, told the Live Science website that breastfeeding is associated with a lower risk of breast cancer. Beneficial bacteria is passed from mothers to their babies during breastfeeding, and this may explain the link.

Prof Reid also highlighted the merits of consuming probiotics or good bacteria to increase breast bacteria in Live Science. In a study in Spain, women who ate probiotics were found to have the same bacteria in their breast tissues as the probiotics they’d consumed.

It is thought that immune cells in the gut may pick up the probiotics and transport them to the breast, said Prof Reid.

Co-senior author Dr. Stephen Grobymer, who is section head of Surgical Oncology and director of Breast Services at Cleveland Clinic, said on Science Daily: "If we can target specific pro-cancer bacteria, we may be able to make the environment less hospitable to cancer and enhance existing treatments.

"Larger studies are needed but this work is a solid first step in better understanding the significant role of bacterial imbalances in breast cancer," he said./.

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