In May 2024, the team of Associate Professor Ming Li from the School of Radiation Medicine and Protection, Soochow University, and Professor Ye Tian from The Second Affiliated Hospital of Soochow University collaborated to publish a research paper online in the journal *Gut Microbes* (Impact Factor: 12.200) entitled "Microbiota-derived I3A protects the intestine against radiation injury by activating AhR/IL-10/Wnt signaling and enhancing the abundance of probiotics" (DOI: 10.1080/19490976.2024.2347722).
Radiation-induced enteropathy (RIE) is a common and severe side effect of radiotherapy. Although several clinical interventions exist, such as drug therapy, probiotic therapy, and surgery, the current treatment outcomes for RIE remain unsatisfactory. In recent years, with the deepening understanding of the interaction between intestinal microbiota and host health, people have come to recognize the important role of metabolites produced by intestinal microbiota in regulating host physiological processes. In this study, the research team isolated and cultured intestinal organoids, and screened a variety of tryptophan metabolites derived from intestinal microbiota. Surprisingly, they found that indole-3-carboxaldehyde (I3A) exhibited the most significant protective effect against radiation-induced injury in intestinal organoids. Further studies revealed that I3A, as a key tryptophan metabolite, treats RIE by activating the aryl hydrocarbon receptor (AhR)/interleukin-10 (IL-10)/Wnt signaling pathway, promoting the proliferation of intestinal epithelial cells, and increasing the abundance of probiotics. This study not only fills the current knowledge gap in RIE treatment strategies but also provides potential targets for the development of new drugs related to radiotherapy, thus holding important clinical application value.
Figure 1 Schematic diagram of the mechanism by which microbiota-derived I3A protects the intestine against radiation injury.
Ph.D. candidate Liwei Xie and Associate Chief Physician Shang Cai from The Second Affiliated Hospital of Soochow University are the co-first authors of this paper. Professor Ye Tian from The Second Affiliated Hospital of Soochow University and Associate Professor Ming Li from the School of Radiation Medicine and Protection, Soochow University, are the co-corresponding authors. This research work was supported by the National Natural Science Foundation of China, the Jiangsu Provincial Science and Technology Program, and other funding sources.