Consistent with a less pronounced obesity-associated microbial signature, wild-type mice receiving fecal microbiota of Acod1-/- littermates gained less weight (Fig. 6A), showed lower fat depots and liver weights (Fig. 6B) as well as increased insulin sensitivity (Fig. 6C and Supplementary Fig. 11A), compared with wild type donors. The gene discussed is ACOD1; the disease is obesity due to melanocortin 4 receptor deficiency.