Therefore, the increased relative abundance of Akkermansia also supported the changes in relative abundances of Firmicutes and Bacteroidetes (Figure 3A) and upregulated levels of two energy metabolism-related proteins (PGC1α and UCP1) (Figure 1K,L) in rats, possibly indicating the reduced risk of obesity and increased lipid oxidation in HMFS-fed rats. Here, UCP1 is linked to obesity due to melanocortin 4 receptor deficiency.