AbstractWe investigated the influence of gut microbiotal metabolism on the pharmacokinetics of berberine in healthy male Africans and Chinese. The C_max and AUC in the Africans were 2.67-fold and 2.0-fold higher than the Chinese, respectively. Microbiotal compositions by 16S rRNA pyrosequencing showed higher abundance of the genera Prevotella, Bacteroides and Megamonas (34.22, 13.88 and 10.68%, respectively) in the Chinese than the Africans (30.08, 9.43 and 0.48%, respectively). Scatter plot showed a strong negative correlation between the microbiotal abundance and the berberine AUC, especially for the genus Prevotella (r = −0.813) and its species. A more extensive metabolism was observed in Chinese with 1.83-fold higher metabolites, possibly contributing to the lower AUC than the Africans. In conclusion, significant PK differences of berberine were observed between Africans and Chinese, which is partly attributable to variations in gut microbiota and its corresponding metabolic capacity.