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A recent study investigated the link between flaxseeds’ effect on gut health and how it may reduce breast cancer risk. Javier Pardina/Stocksy
  • Breast cancer is a serious cancer type. Researchers are still seeking to understand potential risk factors for breast cancer and ways to modify risk.
  • Data from a recent study involving mice helped note the unique link between the gut microbiome and mammary gland expression of microRNA.
  • Results further found that consuming flaxseed may influence the link between the gut microbiome and mammary gland microRNA expression, potentially aiding breast cancer prevention.

Researchers are learning more and more about how the microorganisms in the human gut, the gut microbiome, influence other areas of health. In a recent study published in Microbiology Spectrum, researchers wanted to look at the relationship between the gut microbiome and breast cancer risk.

In their research using female mice, researchers found a key connection between the gut microbiome and gene expression. They further found that flaxseed consumption among mice helped reduce breast cancer risk. While more research is needed, the results have potential clinical implications when it comes to reducing breast cancer risk.

Researchers of this current study wanted to understand more about a specific way to modify breast cancer risk. This particular study involved the analysis of data from female mice. Researchers were able to look at components of the gut microbiome and the associated relationship to breast cancer. The gut microbiome involves the bacteria and other microbes that live within the gut. They were also able to look at data from breast cancer samples and normal samples of breast tissue.

First, they found that the microorganisms in the mice’s guts were related to mammary gland microRNA. They also found that mammary gland microRNA can influence breast cancer development. Study author Dr. Elena M Comelli, Ph.D., Associate Professor, Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, explained to MNT:

“We found that the relative abundance of certain microbiota taxa (bacteria in the gut) is related with the expression of microRNA in the mammary gland. MicroRNA are small molecules that are important for regulating the expression of genes. We found that some of these microRNA are involved in breast cancer related pathways.”

Researchers then examined how the relationship between the gut microbiome and microRNA expression in the mammary gland could be altered. They found that flaxseed consumption among mice helped to alter the relationship between the gut bacteria and the microRNA, thus potentially helping to decrease breast cancer risk. Further analysis of flaxseed components helped support the idea that the most benefit may come from consuming flaxseed as a whole food. Dr. Comelli explained:

“Interestingly, flaxseed was able to beneficially modify these associations. Flaxseed contains lignan, a compound that needs to be metabolized by the gut microbiota to release metabolites that are then absorbed into the circulation. We found the existence of a gut microbiota- mammary gland miRNA relationship, we found that a diet intervention (flaxseed) affects it, and this suggests that there may be a novel route for breast cancer prevention.”

While the data isn’t directly applicable, it could have implications for breast cancer prevention, providing that future research confirms the findings.

Non-study author Dr. Theresa Hubka, an osteopathic physician specializing in OB/GYN and president-elect of the American Osteopathic Association, also commented with her thoughts on the study to Medical News Today:

“[The] research demonstrated the inter-connectivity of the gastrointestinal microbial ecosystem relationship to the miRNA of the mammary glands. They revealed the relationship of the gastrointestinal system to other organs with respect to a specific disease state ie; breast cancer, and subsequent preventive aspects through modifiable dietary changes. Understanding these systems will allow further study in regulation of the genes involved in breast-cancer processes ie; proliferation and migration. Therefore, through nutrition and dietary changes; particular disease states can be mitigated and improve one’s health and well-being.”

Breast cancer is a common cancer type and a significant contributor to cancer-related deaths. In 2020 alone, 685,000 deaths worldwide occurred because of breast cancer. Doctors and cancer specialists can use a combined treatment approach to focus on treating breast cancer. Treatments may involve surgery to remove the cancer, radiation therapy, and medications.

Non-study author Dr. Wael Harb, board certified hematologist and medical oncologist at MemorialCare Cancer Institute at Orange Coast and Saddleback Medical Centers in Orange County, CA, explained to MNT:

“Breast cancer remains a significant global health challenge. It is the most common cancer among women worldwide, with over 2.3 million women diagnosed and 685,000 deaths globally in 2020, as per the World Health Organization. In the United States, about 287,850 new cases and 43,250 deaths are expected in 2023, according to the American Cancer Society. Despite advancements in treatment and early detection improving survival rates, breast cancer’s prevalence and potential severity underline the need for ongoing research and public health initiatives.”

Researching and developing potential treatments are critical components of helping people with breast cancer. However, another key element is learning about ways people can reduce their risk of developing breast cancer. For example, people may be able to minimize their risk for breast cancer by maintaining a healthy weight, limiting alcohol consumption, and exercising regularly. Research is ongoing about how specific interventions can provide the

This research points to the potential for modifying breast cancer risk. However, the research also has critical limitations. The main limitation is that the study involved female mice, so there’s a limited ability to apply the research to people. It indicates the need for more research in this area. Future analysis can also explore the unique relationship between the gut microbiome, mammary gland microRNA, and the components of flaxseed and their impact.

Dr. Harb noted the following clinical implications of the data:

“If further research, particularly in human subjects, corroborates these findings, it could have significant clinical implications. It suggests that dietary interventions, such as flaxseed consumption, might modulate factors related to breast cancer risk. However, the complexity of human biology and the influence of various factors like genetics and environment necessitate comprehensive studies before such findings can be translated into clinical practice. The study points towards exciting possibilities in preventive strategies but also highlights the need for rigorous, large-scale human trials to validate these preliminary findings.”

Dr. Elena M Comelli noted the following regarding future research to MNT:

“At the moment we are studying flaxseed hull, which is enriched in lignans vs flaxseed. Provided in the same amount in the diet, flaxseed hull brings more lignans. We are interested to see if this results in enhanced responses. In addition it will be important to follow up with experimental investigation of our in silico findings. It will be important to study flaxseed in breast cancer models to assess if its preventative benefits are regulated by microRNAs. Findings will help define clinical strategies.”

As research moves forward, it could mean the development of clinical recommendations that could help reduce breast cancer risk or even the number of breast cancer cases.