APOE and atherosclerosis: Acid-hydrolyzed, low-molecular-weight β-glucans from Pleurotus tuber-regium (PTR-HBG) will demonstrate superior prebiotic selectivity and SCFA production in vitro compared to native polymers, and this in vitro advantage will directly translate to a greater reduction in atherosclerosis progression in ApoE−/− mouse models, specifically by enriching for Bifidobacterium spp.