LEP and obesity due to melanocortin 4 receptor deficiency: Lu et al. [91] discovered that SCFAs decreased the expression of DNA methyltransferases (DNMT1, 3a, 3b) in high-fat-diet-induced obese mice, resulting in a reduction in CpG methylation in promoters of the leptin promoter (p < 0.05), thereby suppressing the obesity-related elevated leptin expression.