In this context, obesity has recently been related to lower Clostridium scindens abundance, which is directly correlated to a decrease in non-12-OH BAs and also, to an increase in Turicibacter and Romboutsia, which together, lower GLP-1 levels, and a decrease in hepatic FXR expression [85]. This evidence concerns the gene GCG and obesity due to melanocortin 4 receptor deficiency.