Pomegranate extract stimulates the growth of Akkermansia muciniphila in vivo. A. muciniphila produces ellagic acid from pomegranate extract ellagitannins. A. muciniphila hydrolyses ellagic acid to metabolites other than urolithin A. A. muciniphila plays a role in the breakdown of phenolic compounds in the intestine. A. muciniphila contributes to the prebiotic effect of pomegranate extract.