AHR and inflammatory bowel disease: The indole derivatives-induced AHR activation promotes the local synthesis of the anti-inflammatory cytokine IL-22 by the innate lymphoid cells (Monteleone et al., 2011; Qiu et al., 2012; Yang et al., 2020); IL-22 protects the mucosa integrity against fungal infection by Candida albicans, commonly observed in patients with IBD (Sokol et al., 2017; Gronke et al., 2019).