Supporting The Gut Microbiome During Active Cancer Treatment

We have all heard the euphemism, “trust your gut”, but how does one take care of their gut so that it can function properly? Especially during cancer treatment?

The gut microbiome is made up of trillions of bacteria, fungi, and other microbes along the entire digestive tract. These microbes are incredibly diverse and vary vastly between individuals based on many factors including food, drinks, medications, exercise, geography, work, travel, family, friends and pets.

Overwhelmingly, research indicates that gut health impacts overall health. The gut microbiome in particular plays a critical role in mediating the effects of diet and other factors on health, including digestive, immune, metabolic and neuroendocrine functions. A healthy microbiome is dependent on a balance of healthy bacteria, free of parasites, opportunistic pathogenic bacteria, and yeast. Understanding the pathology behind poor digestive health is key to treating the root cause of disease in the body. For example, an imbalance of unhealthy and healthy microbes (or low gut bacterial diversity) in the intestines may contribute to weight gain, high blood sugar, high cholesterol, and other metabolic disorders. Specific to oncology, it may even impact the success rate of a patient’s chemotherapy treatment and treatment-related toxicities.

There has been ongoing research on how best to support the gut microbiome during active cancer treatment, specifically with immune checkpoint inhibitors (ICI). However, the question remains as to which specific type of bacteria is best to support ICI therapy, or whether it is more beneficial to support the gut microbiome ecosystem as a whole?

There has been some evidence that Akkermansia (1), Bifidobacterium (2), and Ruminococcaceae (3) may all individually improve response rates to PD-1 based ICI in animal models. However, there has been inconsistency to their use in human trials. On the other hand, supporting the gut microbiome as a whole may also modulate the response to ICI. (4) Some of the methods that have been looked at that accomplish such positive microbiome changes include: only using antibiotics before ICI treatment when absolutely necessary, switching from a PPI to an H2 blocker, eating fermented foods, and eating a diverse diet (30 different plants/week) with at least 30g of fiber/day. (4,5,6) The use of supplementary probiotics is somewhat controversial. A consult or referral to a naturopathic oncologist is recommended to provide expert advice on their safe and effective use while using ICI therapy.

How Can One Improve Their Gut Microbiome?

• Eat a diverse range of foods (aim for at least 30 different plants/week)
• Eat fermented foods (kefir, kimchi, kombucha, sauerkraut, yogurt, miso, tempeh, natto)
• Eat foods rich in polyphenols (red wine, green tea, dark chocolate, olive oil, etc.)
• Ensure at least 30g of fiber/day

Research is also being completed to examine the potential of fecal microbiome transplant, targeted antibiotics, bacterial consortia, and bacteriophages to help support the gut microbiome. (4)

For more information on how to support your cancer patients receiving ICI or support their gut microbiome, consider the Advanced Integrative Oncology Palliative Care Course by the Integrative Oncology Institute.