Breast cancer is a complex disease with various contributing factors, including genetics, hormonal imbalances, and environmental influences. While the primary drivers of breast cancer have long been associated with these factors, recent research has raised questions about whether the gut microbiota plays any role in its development. According to Dr. Meghal Sanghavi, who is a Surgical Oncologist, at Wockhardt Hospitals, Mumbai Central, "Gut microbiota can affect hormonal balance by metabolising estrogen, a hormone linked to breast cancer risk. Certain bacteria can influence estrogen levels, potentially increasing or decreasing the risk of breast cancer."


"However, it is crucial to clarify that there is currently no direct correlation or proven data that the gut microbiota are either causative or protective for breast cancer development," said Dr Preetam Jain, who is a Medical Oncologist, at Bhatia Hospital, Mumbai.


But, before knowing the link between gut-microbiota and breast cancer, let us know what gut-microbiota is?


What Is Gut-Microbiota?


Dr. Devavrat Arya - who is a Medical Oncologist, Senior Director, Cancer Care / Oncology, at Max Hospital, Saket, New Delhi said, "The gut microbiota, also known as the gut microbiome, is a complex community of trillions of bacteria, fungi, viruses and other organisms that live in the human digestive tract. They exist in a symbiotically within the digestive system and play a vital role in many aspects of human health, including digestion and immunity. If these microbiomes contribute positively to the human digestive system, the million dollar question is – How can they casue cancer?"


"A number of studies have shown that changes in the gut microbiota composition are associated with an increased risk of breast cancer which has led to a growing interest in the role of gut microbiota in cancer development," he added.


Is There A Link Between Gut Microbiota And Breast Cancer?


Dr Preetam Jain said, "Contrary to the notion that gut microbiota plays a direct causative or protective role in breast cancer, the existing body of scientific evidence suggests otherwise. The gut microbiota primarily influences the digestive and immune systems, affecting overall health and potentially influencing the risk of certain diseases. However, breast cancer does not seem to be one of them."


"It is essential to emphasise that the gut microbiota can indirectly impact health by modulating inflammation and immune responses throughout the body. Chronic inflammation has been linked to cancer development, including breast cancer. Some studies have explored the potential connection between gut health and breast cancer risk, focusing on how the gut microbiota may influence inflammation and immune function. However, these investigations have not provided conclusive evidence to establish a direct link between gut microbiota and breast cancer," he added.


While ongoing research continues to uncover the intricate relationships between the gut microbiota and various aspects of health, there is currently no concrete evidence to suggest that gut microbiota are either causative or protective factors in breast cancer development. Breast cancer remains primarily driven by hormonal, reproductive, and genetic factors. As we advance our understanding of the gut microbiota's role in health and disease, it is essential to rely on evidence-based research and continue to explore potential connections rather than making premature conclusions about their involvement in breast cancer.


Mechanisms Of Gut Microbiota-Mediated Breast Cancer Development:


Talking about this, Dr. Arya said, "The gut microbiota can influence breast cancer development in a number of ways. One mechanism is through the production of metabolites. Certain gut bacteria can produce metabolites that can promote tumour growth and inflammation. For example, some bacteria can produce estrogen-like metabolites that can bind to estrogen receptors on breast cancer cells and stimulate their growth."


"Another mechanism by which the gut microbiota can influence breast cancer development is through inflammation. Chronic inflammation is a known risk factor for cancer, and the gut microbiota can play a role in promoting inflammation. For example, some gut bacteria can produce lipopolysaccharide (LPS), a molecule that can trigger inflammation," he continued to say.


"The gut microbiota also influences breast cancer development by modulating the immune system. The gut microbiota plays a significant role in the development and smooth functioning of the immune system. A dysbiotic gut microbiota can lead to a weakened immune system, which may make it more difficult for the body to fight off cancer cells," he added.


Factors That Can Disrupt Gut Microbiota:


A number of factors can disrupt the gut microbiota, as mentioned by Dr. Devavrat Arya that includes:



  • Diet: A diet high in processed foods and low in fiber can lead to a dysbiotic gut microbiota.

  • Antibiotics: Antibiotics can kill both good and bad bacteria in the gut, which can disrupt the gut microbiota.

  • Stress: Stress can also disrupt the gut microbiota.

  • Certain diseases: Certain diseases, such as inflammatory bowel disease (IBD) and celiac disease (a chronic digestive and immune disorder that damages the small intestine), can disrupt gut microbiota.


Preventing Gut Microbiota Dysbiosis:


Like in all other lifestyle diseases/ailments, gut microbiota dysbiosis too traces its reasons to the oft heard ones – lifestyle changes, avoiding over use of antibiotics, healthy and nutritious food…..to name a few.


In a nutshell, Dr. Devavrat Arya suggested how gut microbiota dysbiosis can be prevented:



  • Eating a healthy diet: A healthy diet for the gut microbiota is high in fiber and low in processed foods.

  • Taking probiotics: Probiotics are live bacteria which are similar to the good bacteria that naturally resides in the gut. Taking probiotics can maintain healthy gut microbiota balance.

  • Managing stress: Managing stress is important for overall health, including gut health.

  • Regular exercises: Exercise is also beneficial for gut health.


[Disclaimer: The information provided in the article, including treatment suggestions shared by doctors, is intended for general informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified healthcare provider with any questions you may have regarding a medical condition.]