HDAC9 and hypertensive disorder: In a recent study, B. intestinihominis bacteria were found to ameliorate hypertension and hepatic metabolic disorders, and B. intestinihominis-derived acetate enhanced fibroblast growth factor 21 by increasing H3 K27 acetylation of the fibroblast growth factor 21 promoter through inhibition of histone deacetylase 9.