One of the most frustrating experiences for an oncologist must be when a drug that works well in one patient fails to do so in another patient. Some of this heterogeneity is due to patient genetics, but it has long been suspected that the microbiome might be a contributing factor as well. Now a series of three papers in Science confirm such an effect for anti-PD-1 therapy of metastatic melanoma. All three papers showed clear differences in the gut microbiome and ability of patients to respond to the drug. Fecal matter from well-responding patients had a clear effect in a mouse model of anti-PD-1 therapy. Finally, one of the papers showed that unfavorable gut microbiome composition could be due to antibiotic treatment, and tracked down a single bacterial species, Akkermansia muciniphila, as having a likely causal role.
comment written by Detlef Weigel