FFAR2 and Crohn disease: Faecalibacterium prausnitzii was also reported to be significantly reduced in the gut microbiota of Crohn’s disease patients compared to those in healthy individuals (Takahashi et al., 2016) and attenuates chronic kidney disease (CKD) via butyrate-mediated GPR-43 signaling in the kidney (Li B. et al., 2022).