How Gut Bacteria Might Influence Ovarian Cancer Treatment

"What we’re interested in is to look beyond the gut microbiome and really look at the cancer itself," says Dr. Stefanie Avril, gynecologic pathologist at Case Western Reserve University in Cleveland. "And we have learned and found that there are actually bacteria living in symbiosis–or living in tumors and around tumors."

These bacterial species also interact with the patient's white blood cells and with cancer cells. By studying those interactions, researchers hope to better understand how the microbiome of an ovarian cancer or of the genital tract can impact how cancers behave. They also hope to learn more about the interaction between a person’s microbiome and their response to cancer treatment.  "Ultimately what we hope to achieve is to find ways to manipulate the microbiome in order to positively impact treatments and response to treatments," says Dr. Avril.

How the Microbiome Affects Treatment Response

Everyone's microbiome is different and unique. The microorganisms that inhabit your gut are acquired very soon after birth, and your body recognizes them as "normal." The first few years of life are the most important ones when it comes to defining what your microbiome will look like.

A person's microbiome can be influenced by many things, including their lifestyle, diet, and the use of medications such as antibiotics, as well as beneficial bacteria supplements, called probiotics. The microbiome, in turn, can influence how our body responds to chemotherapy and other cancer treatments, and the types of side effects we might experience from those treatments.

Researchers are trying to learn about and better understand how those different cancer therapies affect the microbiome inside a tumor, says Dr. Avril. They are also learning how it might be possible to manipulate the microbiome with both drugs, and nutritional/dietary interventions.

Ultimately, once these connections are better understood, they may help patients respond better to cancer treatment, and gain more control over treatment side effects.

Can a Keto Diet Help?

Studies have shown that diet can influence the gut microbiome, which will be part of a new study Dr. Avril and her team are planning to conduct. In collaboration with researchers from other institutions in Cleveland, Dr. Avril’s group will be conducting a pilot study that will look at how dietary interventions can impact the tumor microbiome in ovarian cancers and other gynecologic cancers.

One of the diets under investigation is the ketogenic or keto diet, which has been getting a lot of attention recently. This diet is high in fat with a moderate amount of protein, and very low in carbohydrates. It has been touted as a weight-loss strategy and also used as a treatment for some types of epilepsy. The keto diet is also being studied to help treat some types of cancer.

Switching to a keto diet means changing the amount of carbohydrates versus fatty acids and proteins that a patient eats. This in turn might impact the whole metabolism of the cells in the body. "That’s what we are going to test and study with this pilot study," says Dr. Avril. "We believe that this may also change how the bacteria and the immune system are interacting with a woman’s ovarian cancer cells."

It’s important to mention that the effects of a keto diet on cancer are not yet known, and this way of eating may not be safe for everyone. Anyone who is interested in making changes to their diet during ovarian cancer treatment should first have a discussion with their oncologist.

 

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