PLA2G1B and obesity due to melanocortin 4 receptor deficiency: Indeed, genetic deletion of sPLA2-IB, a digestive sPLA2 that is secreted from the pancreas into the intestinal lumen to degrade dietary and biliary phospholipids (55), also alters gut microbiota (78), although it remains unclear whether or not this event would be functionally linked to the amelioration of obesity-related phenotypes in Pla2g1b–/– mice (79, 80).