We have employed a robust randomized controlled trial using this intrinsic fiber in individuals with obesity at high risk of developing T2D followed by state-of the-art phenotyping of metabolic health with a two-step hyperinsulinemic-euglycemic clamp to assess tissue-specific insulin sensitivity and magnetic resonance spectrometry (MRS) to measure liver fat accumulation, as well as dual X-ray absorptiometry (DEXA) scan, subcutaneous adipose tissue biopsies, and targeted metabolomics, which were combined with advanced gut microbiomics using phylogenetic profiling and deep metagenomic analysis. The gene discussed is INS; the disease is obesity due to melanocortin 4 receptor deficiency.