Can What’s in Your Gut Influence Cancer?

Hosting them in our bodies is a good thing. We have a partnership in which each benefits the other. The host provides a hospitable environment and life-sustaining resources, while the activity of the microorganisms can support our own health. Of special interest these days is the gut microbiome. The human gut is home to an estimated 100 trillion microbes! These creatures are as busy as bees in a hive assisting with a multitude of bodily functions. They start entering our bodies from birth onward.

For example, you are probably familiar with the advice to eat yogurt for digestive health. That’s because yogurt contains bacteria that promote digestion. These organisms come in the form bacteria culture (grown) in a lab and added to milk. They ferment the sugar in milk (called lactose) causing the milk to thicken and acquire a sour taste. Of course, they are still alive when you eat cultured yogurt, and the types are known to be beneficial. Thus, yogurt is one source of a healthier gut biome balance.

The gut biome and your health

Here are just a few of the ways by which your gut microbiome reinforces your well-being:

1. It helps synthesize the nutrients your body needs, like vitamins and minerals
2. It helps transform complex food components so your body can absorb and use them for energy
3. It supports your immune system, partly by protecting against harmful microbes and partly by building tolerance for good microbes.

Thus, the trillions of microscopic organisms in your intestines are partners in your wellbeing.

On the other hand, we’re learning more about problems that can occur if the gut biome becomes unbalanced and can’t hold up its end of the bargain. This is called dysbiosis, resulting in the following possible disease states:

1. Chronic problems within the digest system (irritable bowel syndrome, diverticulitis, Crohn’s disease, inflammation, diarrhea, etc.)
2. New research is connecting Parkinson’s disease and other brain disorders with dysbiosis
3. A 2022 article in the journal Frontiers in Microbiology states that disruptions in the microbiome have been associated with a variety of diseases including “… anxiety, depression, hypertension, cardiovascular diseases, obesity, diabetes, inflammatory bowel disease, and cancer.” 

What about cancer?

As a doctor who specializes in prostate cancer, I’m always on the lookout for new research on how prostate cancer—or any cancer—may begin, and for preventive choices that can help lower cancer risk. I discovered a recent article in the Journal of the American Medical Association or JAMA as it’s commonly called. The title caught my attention, “The Microbiome and Cancer,” by three authors out of the MD Anderson Cancer Center in Houston, TX. 

The authors write, “Microbes in the gut and other locations in the body may influence the development and progression of cancer and may affect the response to adverse effects from cancer therapy.” In other words, the gut biome may be connected with cancer starting, yet it can also have an important part to play in helping cancer treatments be more effective by helping the body respond better to them.

Antibiotics, Immunotherapy, and Gut Health

Part of their evidence for linking gut bacteria with cancer comes from the observation that cancer patients about to receive immunotherapy are first given broad-spectrum antibiotics to help protect them from infection during treatment. And yet, these same antibiotics that kill harmful bacteria also kill healthy bacteria, so their gut biome takes a hit. What appears to happen is that the immunotherapy may shrink the cancer tumors but the patients have worse side effects and poorer overall survival from other conditions. 

That sounds bad, but on the flip side there’s promising news. There are ways to boost the healthy balance of the gut biome, some of them medical, but the one that’s in everyone’s reach is diet and nutrition. The authors note that rebalancing the gut biome through “…strategies such as dietary intervention (egg, high-fiber diet intervention) has improved outcomes in small studies of patients treated with cancer immunotherapy.” 

Diet, Prevention, and Proactive Health

Thus, the microbiome can be a friend or a foe. For me, this raises the question of how to create and preserve the healthiest possible gut microbiome. I turned to information from the well-respected Memorial Sloan Kettering Cancer Center. They sum it up as follows: “Eating a healthy diet can help improve your microbiota. This means eating a diet with lots of fruits, vegetables, and fiber. Fiber supports the growth of many beneficial species in the gut.” This confirms the message I try to get out to everyone, including my prostate cancer patients, on the value of a whole foods/plant-forward diet. Diets like the Mediterranean diet and others are rich in whole grains, fruits, vegetables, nuts, seeds and vegetable fats like olive oil; at the same time, they are low in animal protein but emphasize poultry and fish as alternatives to red meat and processed meats. 

Drawing upon my professional experience with prostate cancer, if I could change one thing in the world it would be this: eat to preserve optimal wellness and to help your gut biome help you! Knowing that the microbes in your gut can help prevent cancer and other diseases, be the best host you can be.

NOTE: This content is solely for purposes of information and does not substitute for diagnostic or medical advice. Talk to your doctor if you have health concerns or questions of a personal medical nature.