Cell 178, 795–806, 2019

The tumor microbiome composition is altered in those with long versus short pancreatic adenocarcinoma (PDAC) cancer survival.

Prognosis upon PDAC diagnosis is poor, although there is a subset of individuals that survive longer. The reasons for this discrepancy are unknown, although there is potentially an influence of the immune system on survival linked to the tumor microbiome.

Florencia McAllister and her colleagues analyzed the microbiomes from tumors of long-term survivors and short-term survivors of PDAC. They found the microbiomes of long-term survivors were more diverse and had a specific bacteria signature. Furthermore, the group found evidence of cross-talk between human gut and tumor bacteria, and based on this they performed human fecal microbial transplants into mouse models of the disease, differentially altering tumor growth and immune profile—indicating a possible mechanism for bacteria to regulate tumors.