MYD88 and obesity due to melanocortin 4 receptor deficiency: Gut microbiota transplantation from MyD88-KO HFD mice into germ-free recipient mice fed a HFD or into mice with intestinal MyD88 deletion after the onset of obesity reduces body weight gain, fat mass development and adipose tissue inflammation, indicating that targeting intestinal epithelial MyD88 constitutes a putative therapeutic approach for obesity and associated disorders.