Good gut microbes help immunotherapy drugs shrink tumours

Options for manipulating the microbiome including changes in diet, avoiding antibiotics, taking probiotics

Cancer patients with high levels of good gut bacteria appear more likely to respond to immunotherapy, potentially opening up a new way to optimise the use of modern medicines that are highly effective but only work on some people.

The finding, reported in two scientific papers on Thursday, suggests patients may in future be told to actively nurture their good bugs when taking so-called PD-1 drugs like Merck & Co’s Keytruda or Bristol-Myers Squibb’s Opdivo.

The twin publications in the journal Science are the latest examples of the importance of the microbiome — the vast community of microbes living inside us —