Common proanthocyanidin-rich foods modulate gastrointestinal blooms of Akkermansia muciniphila in a diet-dependent manner

Developing methods to modulate growth of the mucin-degrading gut bacterium Akkermansia muciniphila could benefit patients with different health needs, as A. muciniphila has been associated with both positive metabolic health outcomes and detrimental neurodegenerative outcomes. Growth of A. muciniphila is sensitive to plant-derived polyphenols, and particularly proanthocyanidins (PACs), when administered in isolated form at supraphysiological doses. However, it remains unclear whether doses sufficient for these effects are achievable via diet. Here, we explore the extent to which nutritionally relevant doses of common polyphenol-rich foods - berries, wine, and coffee - influence A. muciniphila abundance in C57BL/6J mice under varying dietary conditions. By administering polyphenol-rich whole foods, comparing polyphenol-depleted and PAC-rich versus PAC-poor food supplements, and through gradient PAC-dosing experiments, we show that PAC-rich foods uniquely induce A. muciniphila growth at doses that are feasibly achieved through routine diet. Notably, the effects of PAC supplementation were detected against a high-fat diet but not a low-fat control diet background, highlighting the importance of habitual diet strategies in either amplifying or mitigating the prebiotic effects of PAC-rich food consumption. Ultimately, our work suggests that both PACs and diet influence A. muciniphila abundance with downstream impacts for human health.