Fig. 1
From: A metabolite of the gut microbiota: a facilitator of chemotherapy efficacy in cancer

A tryptophan metabolite derived from the gut microbiome accelerates chemotherapy response of pancreatic cancer. Bacteria dwelling in the gut produce indole-3-acetic acid (3-IAA) from uptaken food-derived tryptophan (Trp). 3-IAA translocates to pancreatic ductal adenocarcinoma (PDAC) through the circulation and may be oxidized to toxic molecules (3-IAAP) by myeloperoxidase (MPO) and cytotoxic anticancer drugs of 5-fluorouracil, irinotecan and oxaliplantin (FOLFIRINOX) in intratumoral neutrophils. 3-IAA and FOLFIRINOX in turn induce the downregulation of GPX3/7, reactive oxygen species (ROS)-degrading enzymes, and subsequent accumulation of ROS in cancer cells. Finally, increased levels of ROS suppress the autophagy pathway that is critical in cancer cell proliferation (Created in Biorender.com)