In addition, Akk suppressed the expression of colonic inflammatory factors in PD mice; we further explored its potential mechanism, and found that Akk increased the level of isovaleric acid in the feces of PD mice, and also that isovaleric acid may further up-regulate the expression of SCFAs-related receptors GPR41 and GPR43 in the colon. The gene discussed is FFAR2; the disease is Parkinson disease.