Furthermore, butyrate generated by butyrate-producing bacteria, such as Feacalibacterium prausnitzii, may also exert anti-obesity effects by stimulating GLP-1 secretion from colon L cells via fatty acid receptor (FFAR2)-mediated signaling and mitigating insulin resistance (30, 31). This evidence concerns the gene INS and obesity due to melanocortin 4 receptor deficiency.