How can a healthy gut help cancer treatment?

• Can a healthy gut help cancer immunotherapy?

• What’s the microbiome?

• What were the results?

• What do the scientists have to say?

• What does this mean for me?

At ZOE, we know that your gut microbes play a key role in your health. Each of us has a unique gut microbiome, and our research was the first to identify a distinct set of “good” and “bad” gut microbes that are linked with specific foods and metabolic health.

In the largest study yet, Tim Spector and our colleagues at King's College London have found links between specific gut bacteria and the success of cancer treatment.

Can a healthy gut help cancer treatments?

Researchers around the world have been investigating the importance of the gut microbiome in the response to cancer immunotherapy for some time.

Now, a team at King’s, along with their international collaborators, have looked at specific gut bacteria and the success of treatment for melanoma (skin cancer) in the largest study to date.

Writing in the prestigious journal Nature Medicine, the team explains how complicated this area of research is but also highlights its potential impact. 

Dr Karla Lee, clinical researcher at King's College London and first author of the study, said:

"Preliminary studies on a limited number of patients have suggested that the gut microbiome, as an immune system regulator, plays a role in the response of each patient to cancer immunotherapy, and particularly in the case of melanoma. This new study could have a major impact on oncology and medicine in general.”

What is the gut microbiome?

The gut microbiome is the community of microorganisms that live in the intestines. These microbes, and the balance between beneficial and harmful ones, play a deciding role in immune and overall health. 

Fewer than 50% of people who have advanced melanoma respond positively to immunotherapy, so finding strategies to increase the success is crucial. And gut health may be one way of achieving this.

It’s possible to make changes to the gut microbiome through diet, advanced probiotics, and fecal transplants. 

Knowledge of the best combination of gut bacteria to improve the chances of success could allow doctors to make targeted changes to the gut microbiome before patients start their treatment. 

Which gut bacteria are key?

For their study, the team combined the largest cohort of patients with advanced melanoma (skin cancer) and samples of their gut microbiome from five clinical centers in the U.K., the Netherlands, and Spain. 

The researchers carried out a large-scale metagenomic study (sequencing of the gut microbiome) to investigate whether there was an association between the composition and function of the gut microbiome and the participants’ response to immunotherapy.

The results confirmed that the association between the different gut bacteria in people’s guts and how well they responded to their treatment is complex.

There isn’t a single type of gut bacteria that guarantees success. Different bacterial species showed associations in the various patient cohorts. 

Overall, there were three particular types of bacteria (Bifidobacterium pseudocatenulatum, Roseburia sp., and Akkermansia muciniphila) that seem to be associated with a better immune response. 

An additional finding was that the microbiome itself is strongly influenced by factors — including the physical functioning of a patient’s body, use of proton pump inhibitors, and diet — as we’ve discovered in studies previously that have helped to inform how the ZOE nutrition program works.

What do the scientists have to say?

"This study shows the chances of survival based on healthy microbes nearly doubled between subgroups. The ultimate goal is to identify which specific features of the microbiome are directly influencing the clinical benefits of immunotherapy to exploit these features in new personalised approaches to support cancer immunotherapy. But in the meantime, this study highlights the potential impact of good diet and gut health on chances of survival in patients undergoing immunotherapy."

“Our study shows that studying the microbiome is important to improve and personalise immunotherapy treatments for melanoma. However, it also suggests that because of the person-to-person variability of the gut microbiome, even larger studies must be carried out to understand the specific gut microbial features that are more likely to lead to a positive response to immunotherapy.” 

What does this mean for me?

If you’re currently undergoing immunotherapy for cancer, particularly melanoma, you should always speak to your consulting physician to get the best advice for your particular situation.

With the power of community science on the ZOE COVID Study app, we hope to answer more questions in the future about the role your immune health plays in the development and treatment of health conditions, including cancer, heart disease, and dementia.

Sign up now to vote for your preferred studies and to fill in your health profile.

For more information on how to improve your gut microbiome for better immune and metabolic health, take our free quiz.

You can also visit our ZOE Health Academy website, where you can find lots of helpful articles or sign up to join the ZOE program, available now in the U.S. and coming soon to the U.K.