Investigating the stimulatory mechanisms of phlorizin, phloretin and chlorogenic acid polyphenols on Akkermansia muciniphila in vitro

Plant polyphenol extracts are shown to have prebiotic-like, stimulatory effect on Akkermansia muciniphila. A. muciniphila is a potentially health beneficial commensal gut microbe that utilizes mucin for energy. However, the exact mechanism of the stimulation is unknown. In this study, mechanisms that may lead to competitive advantages for A. muciniphila were tested using pure forms of phlorizin, phloretin, and chlorogenic acid in vitro. The polyphenols had no significant effect on the production of mucin by the host cells. No significant inhibition of the bacterial growth by phlorizin or chlorogenic acid were observed up to 1000 μM. However, phloretin significantly inhibited the growth of mucus-associated competitors of A. muciniphila except for Escherichia coli at 250 μM. The polyphenols tested may not directly affect mucin production by the host or function as prebiotics. Rather, the stimulation of A. muciniphila may be due to its higher tolerance for polyphenols relative to competitors.