Transplantation of TLR5−/− microbiota into wild type germ-free mice conferred many aspects of the TLR5−/− phenotype to the wild type germ-free hosts, including hyperphagia, obesity, hyperglycemia, insulin resistance, and elevated levels of proinflammatory cytokines [13]. The gene discussed is TLR5; the disease is obesity due to melanocortin 4 receptor deficiency.