FIGURE 3.

Metabolites enhance satiety and inhibit eating. Through bile acid (BA) receptors (Takeda G‐protein‐coupled receptor 5 [TGR5] and farnesoid X receptor [FXR]), short‐chain fatty acid (SCFA) receptors (GPR41/43), Toll‐like receptor (TLR) of intestinal cells, and enhanced Ca²⁺ entry, L cells can promote the release of intestinal hormones (glucagon‐like peptide 1 [GLP‐1]/tyrosine tyrosine [PYY]), activate hypothalamus proopiomelanocortin (POMC) and inhibit neuropeptide Y (NPY) to improve satiety. Meanwhile, BAs and SCFAs can cross the blood–brain barrier, and BAs enhance satiety through TGR5 receptors in the hypothalamus. SCFAs increase lactic acid and inhibit NPY. Otherwise, SCFAs promote the level of growth hormone, which can control energy homeostasis by stimulating lipolysis and protein retention.