GPT and obesity due to melanocortin 4 receptor deficiency: First, the selection of outcome measures has inherent constraints: Although ALT and AST are widely used, they lack specificity and cannot distinguish the source of inflammation; PDFF quantifies fat content but does not evaluate inflammatory activity or fibrosis, which are key determinants of MASLD prognosis; BMI, as an indicator of obesity, fails to distinguish fat distribution, which may obscure potential FMT effects on body composition; and Histological endpoints were not included, making it difficult to directly evaluate improvements in MASH.