We hypothesized that sampling for the measurement of L-FABP and I-FABP levels, as well as defensins 5 and 6 in the serum of children with obesity and MASLD, might explain the cause of metabolic disturbances in children with obesity and MASLD and confirm or disprove whether intestinal microbiota translocation could influence the development of obesity and MASLD. The gene discussed is FABP1; the disease is obesity due to melanocortin 4 receptor deficiency.