GCG and obesity due to melanocortin 4 receptor deficiency: Further, Bacteroidetes have been found to possess anti-obesity effects, which can inhibit obesity and promote branched-chain amino acid catabolism in the brown adipose tissue [40], and improve insulin sensitivity and serum glucagon-like peptide-1 [41], which aligns with the phenomenon of an increased ratio of Firmicutes to Bacteroidetes (F/B) in the gut of obese children.