The Gut Microbiome and Cancer: Understanding the Connection

Have you heard of the microbiome? How about the gut microbiome and cancer link? 

There’s a chance you haven’t, because this field of research is still considered rather new. In fact, most of what we know about the microbiome has only been discovered in the last 20 years or so. But the emerging research is very interesting and quite promising, showing a clear link between microbiome health and tumor growth and treatment outcomes. 

Today, I’m sharing what scientists know so far about this connection and what you can do to improve the health of your microbiome. 

What Is the Microbiome? 

The microbiome is the community of microorganisms, like bacteria (both good and bad), that inhabit the systems throughout our bodies. While research on it in general is still emerging, scientists have made significant discoveries about its role in our overall health, particularly when it comes to cancer. 

The Gut Microbiome and Cancer: What the Research Shows

The connection between gut health and cancer started with research on colorectal cancer, which makes sense given the clear location-based link. However, microbiome health has since been shown to have an impact on many different kinds of cancers throughout the body. 

Interestingly, the research is also now showing that microbiome health isn’t just related to your gut. Instead, it’s systemic, meaning it affects all the systems in our bodies. 

Microbiome health has been found to impact both tumor growth as well as treatment response. A healthy microbiome can be an indicator of someone responding well to immunotherapy (which is a relatively new cancer treatment that uses your body’s immune system to fight the cancer cells), whereas the opposite can also be true. An unhealthy microbiome can lead to less response from immunotherapy. 

What Impacts Your Gut Microbiome and Cancer Risk

We are all born with a healthy microbiome. But over time, the foods we consume and other environmental factors affect it, killing off “good” bacteria and leaving the “bad” bacteria behind. And when our microbiome is unhealthy, our cancer risk is increased. 

Things that negatively impact your microbiome include:

• Processed foods

• Foods high in added sugar

• Fried foods

• Alcohol and smoking

• Chronic stress

• Overuse of unnecessary antibiotics* 

*Always consult your doctor regarding antibiotic use. This post is not advising you to stop taking prescribed antibiotics. 

Things that positively impact your microbiome include:

• Whole foods, particularly high-fiber and probiotic foods

• Stress management

• Getting good sleep

• Staying hydrated 

Foods That Support a Healthy Microbiome

A healthy microbiome is a varied one with lots of good bacteria, which means you want to eat a healthy, varied diet as much as possible. 

Fermented goods, in particular, can have a really positive impact on improving your microbiome because they’re rich in probiotics. 

Things like live culture yogurt, sauerkraut, kimchi, sourdough bread, kefir, tempeh, and miso are really great to incorporate into your diet. Just keep in mind that these foods should be heated before you consume them (with the exception of sourdough bread), because the heat kills off the good bacteria. 

Overall, a microbiome-healthy diet includes: 

• Lots of different plant foods for variety

• Prebiotic-rich foods (such as garlic, onions, and leeks)

• Oily fish and other omega-3 fatty acids to fight inflammation

• Regular fermented foods (daily, if possible)

• Polyphenol-rich foods like berries, dark chocolate, walnuts, and red wine in moderation

The key is variety and consistency. The more diverse your diet of whole, nutrient-dense foods (and the less you consume processed foods), the more diverse and healthy your microbiome will be. 

Cancer Coach & Navigator 

The research on the gut microbiome and cancer is still emerging, but what we’re learning is incredibly promising. By making simple dietary and lifestyle changes to support a healthy microbiome, you may be able to positively impact your cancer risk and treatment outcomes. 

Start small, like by adding a serving of fermented foods to your daily (or even weekly) routine, increasing your fiber intake with more plant-based foods, managing your stress, and prioritizing your sleep. These small changes can make a big difference in your overall health and your microbiome. 

If you’re currently in cancer treatment or survivorship and want personalized guidance on nutrition, exercise, and lifestyle changes that can support your healing, that’s exactly what I offer. I encourage you to reach out and schedule a complimentary consultation to see if working together would be a good fit.