Commensal Clostridia are strongly involved in maintaining the overall gut function; in a previous study, Clostridium asparagiforme and Clostridiales bacterium 1_7_47FAA increased and were positively correlated with postprandial GLP-1 in patients with obesity after SG (65). The gene discussed is GCG; the disease is obesity due to melanocortin 4 receptor deficiency.