MUC5AC and obesity due to melanocortin 4 receptor deficiency: Sulfate-reducing bacteria, Desulfovibrio, are reported to be associated with a high-fat diet,30 and its co-occurrence in the gut with Prevotella has been speculated to work synergistically for degrading mucin.31Desulfovibrio has been reported in autistic children.32 A study on colorectal cancer showed that the richness of Desulfovibrio in the gut was associated with AA patients.33 In the present study, Desulfovibrio did not markedly correlate with obesity.