GCG and obesity due to melanocortin 4 receptor deficiency: BB also positively impacts gut homeostasis and signalling pathways by increasing the expression of genes such as Occlu, Glp1, and Npy. Finally, BB can shape gut microbial populations (e.g., Desulfovibrio), which can facilitate glutamate degradation, thereby potentially affecting obesity, type 2 diabetes, and even depression.