Breast Cancer and the Microbiome

Women in pink shirts holding Breast Cancer awareness ribbonsOctober is Breast Cancer Awareness Month. We want to help bring awareness to breast cancer and share some information on how the gut microbiome can impact it all. 

As of 2021 breast cancer is the most common type of cancer throughout the globe. It is the second deadliest cancer in US women. And while breast cancer predominantly affects females, the rates in men have gone up in recent years due to obesity and rising estrogen levels in men. Breast cancer will affect nearly 1 in 8 US women and 1 in 833 men

With rising cases of breast cancer, learning what you can do to prevent (as much as you can) and what can affect your survival rates are key to understanding the disease and its progression. 

What is breast cancer?

Breast cancer is a disease where tumors grow in breast tissue that are cancerous. Tumors are the result of cells multiplying too quickly and eventually creating a mass. When normal cells are what created the mass it is benign and non-cancerous. However, when abnormal cells create tumors they become cancerous. 

Breast cancer, like other cancers, will be graded by stages of severity.

  1. Stage 0 — breast disease (non-cancerous/pre-cancerous) is only in the milk ducts 
  2. Stage 1 — breast cancer is less than 2 cm and has not spread past the ducts
  3. Stage 2 — is one of the following
    1. IIA —  tumor (less than 2cm) has spread to the underarm lymph nodes 
    2. A tumor is between 2-5 centimeters — may or may not involve the lymph nodes
    3. IIB — the tumor is greater than 5 cm but has not moved to the lymph nodes 
  4. Stage 3 — dubbed “locally advanced breast cancer”
    1. IIIA — any size tumor with cancerous lymph nodes that stick to each other or adjacent tissues
    2. IIIB — any size tumor that spread to the skin, chest wall, or internal mammary lymph nodes
  5. Stage 4 — breast cancer that has spread to other areas of the body like the bones, liver, or lungs

There are many different subtypes of breast cancer that can determine which type of treatment would work best based on stage and type

What factors contribute to breast cancer?

There is no one etiology of breast cancer. While many think that it is mostly genetic, 85% of patients have no family history of breast cancer. 

There are some genetic factors that predispose people to get breast cancer:

  • BRCA1 gene mutation
  • BRCA2 gene mutation

Outside of genetics, there are multiple factors that can contribute to breast cancer, including but not limited to:

  • Age (40+)
  • Gender (female)
  • Obesity
  • Poor diet
  • Not breastfeeding after having a baby
  • Hormone-based prescriptions
  • Certain birth controls


How does the gut affect breast cancer?

The gut microbiome has been referred to as the second brain and is often considered its own organ. The trillions of microbes that live there alter and affect so much of what happens with our bodies — cancer development and progression included. 

While people often think of the gut when they hear the term ‘microbiome’, we actually have several other microbiomes in our bodies — the breast microbiome being one of them. 

The different microbes in each microbiome are able to cross-talk with each other by sending chemical signals from one area to the other. While generally, these are healthy chemical signals, disruptions in either microbiome (called dysbiosis) can cause a shift in the other, leading to malfunction and disease.

Estrogen is often found to be the instigator of most breast cancers (approximately 70%). The gut microbiome is a large mediator of estrogen levels. We see a rise in estrogen levels when people are obese and eating high-fat diets. This rise in estrogen in both the gut and breast is another factor where the gut can affect breast cancer. 

Scientists have found a correlation between certain unhealthy bacteria within the gut and breast microbiomes that can be linked to breast cancer. 

Bacterioides fragilis is a bacteria that can produce B. fragilis toxin. This specific bacteria has been found in breast cancer tissues and colonized in the gut as enterotoxigenic Bacteroides fragilis (ETBF). B. fragilis and its associated toxins were found to promote breast cancer progression

On the other hand, certain bacteria like Gemmiger formicilus and A. muciniphila have been shown to help improve treatment and prognosis for breast cancer patients. Patients who had these bacterial strains within their gut microbiome responded better to treatment than those without. Both of these bacteria are associated with lower BMI and weren’t found in the guts of obese patients. 

This is why diet can be a huge modulator in gut health and cancer prognosis.

How can diet improve breast cancer treatment?

Foods that help fight against CancerDiet is always something your doctor will talk to you about when it comes to any type of condition — and for good reason. The foods that we eat help to shape our microbiome and give us the nutrients and microbial byproducts our bodies need to remain healthy. It’s no different for cancer patients.

While diet won’t completely cure or rid a patient of their disease it can help to slow its progression and improve treatment.

Dietary factors were proven to affect cancer progression in mice. 

One group of mice was given a high-fat diet (HFD) while the other consumed a low-fat diet (LFD). The HFD cancer mice had their disease progress faster and become more aggressive than their LFD counterparts. The microbiota from the HFD mice was transplanted into the LFD specimen and their disease became more aggressive as a result. 

High-fat diets are associated with all diseases in one way or another. 

Eating diets that are full of polyphenols, prebiotics, and postbiotics can help to improve gut and body health. 

Some supplements can offer extra of these essential nutrients as Atrantil does. Ask your doctor if Atrantil can help to alleviate some gastrointestinal symptoms for you. Cancer patients often experience bloating, diarrhea, constipation, and abdominal pain from disease and treatments and Atrantil may be able to help you manage these symptoms. 

How can you best support someone who has breast cancer?

Breast cancer is a scary diagnosis and people may not know how to ask for help when they have been diagnosed. You can help someone you know with a cancer diagnosis by treating them just like you always have. 

Be understanding that some days they may feel worse than others, but don’t baby them either. Give them a listening ear for when they need it and offer to help where you can. They often don’t fully understand their diagnosis so it can be hard to relay that information. Help them keep as much normalcy in their routine as you possibly can — ask them to come for walks with you or to try a healthy new recipe (find some inspiration on our blog).

Cancer in all forms can be scary, but having a support system to lean on for your harder days can make all the difference in the healing journey along the way.