TAF1 and obesity due to melanocortin 4 receptor deficiency: Although caution is needed in interpreting results, the analysis presented here suggests that a high-fat low-MACs diet, in the context of metabolic deregulation, such as obesity and T2D, could force changes in the GM CTs, supporting the presence of CCG1 (S. variabile group) and/or CCG3 (R. bromii group) to the detriment of CCG2 (E. rectale group).