INS and obesity due to melanocortin 4 receptor deficiency: Figure 7A illustrates that Proteobacteria and Desulfovibrio were positively related to mouse BGL, serum insulin, ALT and TC levels, indicating that an elevation in the abundance of these gut microbiota exacerbates the damage caused by obesity-induced IR. Conversely, Firmicutes and Lactobacillus were negatively associated with mouse BGL, TC level, and glucose tolerance, suggesting that changes in the abundance of gut microbiota induced by zeaxanthin treatment can improve IR.