Figure 6.

Indole derivatives originating from the gut microbiota exert anti-inflammatory effects through the AHR. Indole derivatives, generated by the microbial conversion of dietary Trp, can activate AHR in Group 3 innate lymphoid cells (ILC3s), thereby promoting IL-22-mediated tissue protection. Indole derivatives can activate AHR in T cells, leading to the generation of Tregs and subsequent reduction in inflammation, resulting in improved disease outcomes in EAE. Additionally, AHR in microglia contributes to the suppression of inflammation in EAE.