Sciencemag: Microbiome Linked to Cancer Immunotherapy Drug Response Thru T-cells

The gut microbiome helps determine whether tumors shrink when treated with immunotherapy drugs "human studies" now show. "These are the best-done and largest assessments of how the microbiome may influence therapeutic outcome" Jeffrey Weber, NYU.

Responders had a more diverse microbiome and more of specific bacteria. Patients on antibiotics which disrupt the microbiome relapsed sooner and didn't live as long.

Researchers found the cytokine IL12 released in response to the species A.muciniphila seem to help PD-1 blockers[drugs] by priming T-cells.

"The new studies have 'tremendous implications,"' Jennifer Wargo, MD Anderson Cancer Center, such as avoiding antibiotics while on PD-1 blockers and manipulating the gut microbiome with fecal transplants (pill form) or bacterial treatment to increase immunotherapy response rates.

3 November 2017 Science article may be behind a paywall:
http://science.sciencemag.org/content/358/6363/573