The first study of the microbiome – the community of microorganisms – in human breast ductal fluid has shown differences between the bacteria found in women who have experienced breast cancer and the bacteria present in those who have not. The study results open the door to the investigation of the potential role of microbes in breast cancer development.

Published in the online journal Scientific Reports on June 21, the study was conducted by a multi-institutional team led by Susan Love, M.D., M.B.A., Founder and Chief Visionary Officer of Dr. Susan Love Foundation for Breast Cancer Research; Delphine Lee, M.D., Ph.D., director of the Department of Translational Immunology and of the Dirks/Dougherty Lab for Cancer Research of Providence Saint John’s Health Center’s John Wayne Cancer Institute; and Parag Vaishampayan, Ph.D., a scientist at NASA’s Jet Propulsion Laboratory.

Prior to this study, researchers have documented the existence of bacteria in the breast tissue. However, this collaboration marks the first exploration of a link between the breast ductal fluid microbiome and breast cancer.

“We don’t yet know nearly enough about healthy and cancerous breasts – neither the microbial landscape nor the anatomy of the breast duct system,” Dr. Love said. “Yet, all breast cancer begins in the ducts, so clearly exploration is critical to discovering what causes breast cancer and how we can eradicate the disease.”

The research team found that the microbiome in breast ductal fluid differed significantly between two groups, 23 healthy women and 25 women who had a history of breast cancer. Fluid was obtained through suction on the nipple and analyzed via next-generation genomic sequencing.

The research findings set the stage for further study on the role microbes may play in causing or preventing breast cancer. They are in line with recent research studies that suggest microbes contribute to 16 percent or more of malignancies worldwide.

“We have known for decades that our immune cells and the cells that line our organs’ surfaces can react to microbial components,” Dr. Lee said. “These responses can trigger inflammation and immune responses, suggesting that this interaction might help the immune system monitor breast tissue for cancer, or that certain microbes could contribute to increased inflammation that leads to cancer development. There is still so much to explore.”

Drawing on its expertise in genomic sequencing, the Jet Propulsion Laboratory team employed a cutting-edge data analysis technique to identify the bacteria existing in the breast ductal fluid. Used primarily to characterize the microbial ecology related to outbound spacecraft in an effort to protect other worlds, this analytical methodology is proving useful in disciplines other than astrobiology.

“Collaboration between medical researchers and experts in bioinformatics and other disciplines will continue to propel groundbreaking discoveries,” said Dr. Vaishampayan.

“This publication represents a success for JPL’s Medical Engineering Forum Initiative, which focuses on applying NASA technology for medical needs here on Earth,” added JPL’s Leon Alkalai, Ph.D., who is spearheading the initiative.

About Dr. Susan Love Foundation for Breast Cancer Research

Dr. Susan Love Foundation for Breast Cancer Research is dedicated to achieving a future without breast cancer by engaging the public and the scientific communities in innovative research. The Foundation does this through performing and facilitating innovative and collaborative research, translating science to engage the public as informed partners, and inspiring novel research. The Foundation drives progress by being fast, flexible, and project-based, providing its expertise and resources to find new solutions to eradicating breast cancer.

For more information, contact:

Alanna Fearing
Director, Communications and Marketing
Dr. Susan Love Foundation for Breast Cancer Research

310-828-0060, ext. 172

About Providence Health & Services

Providence Health & Services, Southern California, is a Catholic not-for-profit, mission-driven healthcare system. Providence Southern California operates six award-winning hospitals and a comprehensive, fully-integrated network of primary care clinics, urgent care centers, home care, TrinityCare and TrinityKids Care hospice as well as Providence High School. Providence is anchored locally by Providence Holy Cross Medical Center in Mission Hills, Providence Saint Joseph Medical Center in Burbank, Providence Saint John’s Health Center in Santa Monica, Providence Tarzana Medical Center and Providence Little Company of Mary Medical Centers in Torrance and San Pedro. With more than 3,400 physicians, Providence provides coordinated primary and specialty care through an array of physician groups and individual providers including Providence Medical Institute and physician groups in the South Bay, the West Valley and Santa Clarita. Providence affiliate, Facey Medical Group, provides primary and specialized care in the San Fernando, Santa Clarita and San Gabriel valleys. For more information, visit

For information, contact:

Patricia Aidem
Director, External Communication
Providence Health & Services, Southern California

818 496-4780


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We combat the disparities that exist in research by challenging the scientific community to launch studies that are as inclusive and diverse as the people that breast cancer affects.

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