Given the limited amount of literature focusing on the connection between PPAR-α, FGF-19, and butanoate metabolism, it is suggested that butyrate can upregulate PPAR-α in hepatocytes, thereby alleviating HFD-induced MASLD in rats through the activation of β-oxidation and inflammation suppression 71. The gene discussed is FGF19; the disease is metabolic dysfunction-associated steatotic liver disease.