GPBAR1 and obesity due to melanocortin 4 receptor deficiency: For instance, supplementation with Lyophyllum decastes polysaccharides, Bacteroides intestinalis, and Lactobacillus promotes the increase of secondary bile acids, regulates TGR5 expression, and upregulates energy metabolism-related genes such as PGC-1α, and Ucp1, leading to increased thermogenesis and the alleviation of obesity [105].