Here, we demonstrated that administration of LKU4, a probiotic bacteria, to HFD mice resulted in increased mitochondrial levels and activity and enhanced the expression of BAT-specific genes such as Ucp1 and Cidea in iWAT; this, in turn, activated adipocyte browning and enhanced body temperature, resulting in protection from diet-induced obesity. The gene discussed is UCP1; the disease is obesity due to melanocortin 4 receptor deficiency.