You’ve Got Guts: Protect Against Cancer

Authored by: Hanni Yang

When we think of the world's deadliest diseases, the most fatal outbreaks such as HIV/AIDS or COVID-19 may come to mind. However, we often forget that cancer remains one of the most lethal. 

As the second leading cause of death globally, cancer’s impact is both profound and personal. According to the World Health Organization, cancer caused 9.6 million deaths globally in 2018 meaning that one out of every six people die due to cancer [1]. Scientists are trying to solve this problem by conducting different kinds of research to explore how gut microbiomes, the overlooked hero of health, help fight cancer.

The gut microbiome is a group of microorganisms, including bacteria, viruses, and other microbes, that live in the gastrointestinal tract. It assists with digestion, nutrient absorption, and even allows people to control their immune system. So how does the gut microbiome help prevent cancer and support recovery? 

The microbiome plays a crucial role in inflammation and regulation of the immune system, both of which are key for cancer prevention. Chronic inflammation, in particular, is a risk factor for cancers like pancreas and gastric. More specifically, inflammation is the body being on “high alert,” ready to fight off the cancer by triggering an immune response against disease and injury. To reduce inflammation and prevent cancer development, a healthy, balanced gut microbiome is necessary. It stabilizes the body’s defense system, preventing it from overreacting. This in turn would prevent any potential damage that could progress to cancer [2].

Moreover, gut microbiomes regulate immune function. For instance, gut bacteria boost the body's immune response to abnormal cells, including cancer cells. This immune modulation allows the immune system to effectively detect threats, such as cancer cells, and kill them before they become tumors, which are groups of abnormal cells that form lumps [2]. According to a research study by Juliana Durack and Susan V. Lynch, individuals with a diverse gut microbiome have a better immune response and are less likely to have chronic diseases like cancers [3].

In addition to its role in reducing cancer risk through inflammation and immune regulation, the gut microbiome also influences how the body reacts to cancer treatment through immunotherapy. Immunotherapy is a treatment that uses a person’s own immune system to fight cancer cells. This is done in two ways: boosting its natural defenses and creating substances to restore its natural function [4]. 

A study, conducted by Dr. Gopalakrishnan and additional researchers, explored how the gut microbiome influences the effectiveness of immunotherapy in melanoma patients. They found significant differences in gut bacteria between patients who responded positively to treatment (“responders”) and those who didn’t (“nonresponders”). Responders had higher diversity in their gut microbiome. Gut bacteria in responders also had more metabolic pathways that support anabolic functions, contributing to stronger immune responses. These findings reveal that the gut microbiome plays an important role in how well melanoma patients respond to immune checkpoint inhibitors, which could impact future treatments [5]. Moreover, this study prompts scientists and doctors to explore how the gut microbiome may similarly affect the capacity of immunotherapy for other types of cancer, such as lung and kidney cancer, where the nonresponding patients with lung and kidney cancers had low levels of the bacterium Akkermansia muciniphila. Learning how the gut microbiome helps with immune regulation can provide new treatments for diseases associated with weak immune responses.

Steve Rowley, a cancer survivor, was diagnosed with Stage 3C colon cancer in 2015. He never thought he would get cancer since he didn’t have any genetic predisposition. However, age is crucial; many elders who are 50 or 60 years or older will have a high risk of getting cancer. Steve was 60. Steve experienced the death of his brother who had Stage 4 colon cancer and passed away within six months. Steve began to take rehabilitation classes and educated himself on cancers and became a promoter of cancer prevention awareness. Steve made lifestyle changes such as participating in fitness circuit classes and frequently walking his dog. Steve understood that “exercise and a healthier diet together help to develop a healthy gut microbiome and strengthen the immune system.” While it’s unclear if these changes directly influence the growth of cancer, Steve believes that they played an important role in supporting his overall health and recovery. Steve shared, “I am now very in tune with my gut microbiome and its needs” [6].

So how can you maintain a healthy gut microbiome and prevent cancer? It’s simpler than you might think. Lowering stress levels, getting enough sleep, staying hydrated, and eating slowly can all help you maintain a healthy gut. You can spend time with loved ones and meditate to relieve stress since the hormones that your body releases can negatively affect your gut. Eating slowly can lower the chance of developing obesity and diabetes, and drinking more water can increase gut bacteria diversity [7].

The gut microbiome plays a significant role in cancer treatment and overall health. Learning about recent research and cancer survivors’ stories can help people become more aware of cancers and the role the microbiome plays in fighting cancers. So, who knew a group of tiny microbes could become the unsung heroes in the body that fight against cancer? By taking small steps each day to take care of your gut, it supports digestion and lowers your chance of developing cancer. 

Works Cited

1. World Health Organization. (2019, July 12). Cancer. World Health Organization (WHO). Retrieved October 7, 2024, from https://www.who.int/health-topics/cancer#tab=tab_1

2. Al Bander, Z., Nitert, M. D., Mousa, A., & Naderpoor, N. (2020). The Gut Microbiota and Inflammation: An Overview. International journal of environmental research and public health, 17(20), 7618. https://doi.org/10.3390/ijerph17207618

3. Durack, J., & Lynch, S. V. (2019). The gut microbiome: Relationships with disease and opportunities for therapy. The Journal of experimental medicine, 216(1), 20–40. https://doi.org/10.1084/jem.20180448

4. American Cancer Society. (2019, December 27). Treating Cancer with Immunotherapy | Types of Immunotherapy. American Cancer Society. Retrieved October 7, 2024, from https://www.cancer.org/cancer/managing-cancer/treatment-types/immunotherapy/what-is-immunotherapy.html

5. Gopalakrishnan, V., Spencer, C. N., Nezi, L., Reuben, A., Andrews, M. C., Karpinets, T. V., Prieto, P. A., Vicente, D., Hoffman, K., Wei, S. C., Cogdill, A. P., Zhao, L., Hudgens, C. W., Hutchinson, D. S., Manzo, T., Petaccia de Macedo, M., Cotechini, T., Kumar, T., Chen, W. S., Reddy, S. M., … Wargo, J. A. (2018). Gut microbiome modulates response to anti-PD-1 immunotherapy in melanoma patients. Science (New York, N.Y.), 359(6371), 97–103. https://doi.org/10.1126/science.aan4236

6. Rowley, S. (2024, April 25). I didn't know I was at risk: Steve's bowel cancer story - Bowel Research UK. Bowel Research UK. Retrieved October 9, 2024, from https://www.bowelresearchuk.org/latest-news/bowel-cancer-microbiome-steves-story/

7. Taylor, C., Dix, M., & Olsen, N. (2018, July 2). How to Improve and Reset Gut Health. Healthline. Retrieved October 7, 2024, from https://www.healthline.com/health/gut-health#what-to-do