In keeping with this, the treatment of HFD-fed animals with the three selected A. muciniphila strains that showed a marked anti-obesity effect, decreased the peak OGTT glucose level, OGTT AUC, serum insulin level, HOMA-IR significantly, as well as hepatic gene expression of hepatic G6Pase and upregulated the colonic gene expression of PYY significantly. The gene discussed is PYY; the disease is Obesity.