Dietary supplementation with tryptophan or its precursors has been demonstrated to ameliorate symptoms of inflammatory bowel disease(IBD), enhance sleep quality, improve mood states, and may potentially prevent hypertension in offspring induced by maternal chronic kidney disease(CKD), likely through modulation of the microbiota-metabolite-AHR axis (Hsu et al., 2020). Here, AHR is linked to chronic kidney disease.