‘Having a happy gut with a good mix of bacteria may improve cancer treatments’

A new study looking into melanoma and gut microbiome found that there was a link between the bacteria’s composition and response to immunotherapy, says Dr Miriam Stoppard

Having a happy gut, containing the right mix of bacteria, is being linked to more and more surprising health benefits, ranging from your heart to your ­ mental health.

And here’s another one: it could improve cancer treatments.

That is the conclusion of researchers from five clinical centres in the UK and across Europe studying our gut ­microbiome – the ­population of bacteria in our digestive system.

Their study gathered the largest group of patients with ­melanoma – a type of skin cancer – and matched samples of their gut ­microbiome.

Researchers did genetic sequencing of the bacteria to see if there was a link between its composition and the response to immunotherapy.

This cancer treatment works by helping the immune system recognise and attack cancer cells.

But less than half of patients with melanoma respond positively to ­immunotherapy, so finding new strategies is crucial.

Our microbiome can be altered through dietary changes, faecal ­transplantation and next-generation probiotics.

This alteration in turn modifies the microbiome’s action on the immune system.

Understanding the characteristics of the microbiome could enable doctors addressing cancer to alter a patient’s before starting treatment to improve its effectiveness.

“Preliminary studies on a limited number of patients have suggested 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,” says first author Dr Karla Lee, from the ­Department of Twin Research and Genetic Epidemiology at King’s College London.

“This new study could have a major impact on oncology and medicine in general.”

Results confirmed a complex ­association as it involves different bacterial species in different patient groups.

Three types of bacteria ­(Bifidobacterium pseudocatenulatum, Roseburia spp and Akkermansia muciniphila) seem to be associated with a better treatment response.

“This study shows the chances of survival based on healthy microbes nearly doubled between subgroups,” says Professor Tim Spector, also from King’s College London.

“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.”

Co-author Professor Nicola Segata from the University of Trento in Italy said: “Our study shows that studying the microbiome is important to improve and personalise immunotherapy treatments for melanoma.”

Because of microbiome variations from person to person, more studies are needed, but it’s an exciting start.