Dietary Intake of Yeast‐Derived β‐Glucan and Rice‐Derived Arabinoxylan Induces Dose‐Dependent Innate Immune Priming in Mice

Beta‐glucans and arabinoxylans are known for their immunostimulatory properties. However, in vivo these have been documented almost exclusively following parenteral administration, underemphasizing oral intake. C57BL/6 mice are fed either a control diet or a diet supplemented with yeast‐derived whole β‐glucan particle (yWGP) or with rice‐derived arabinoxylan (rice bran‐1) at a concentration of 1%, 2.5%, or 5% weight/weight (w/w) for 2 weeks. Thereafter, cells from blood, bone marrow, and spleen are collected for ex vivo stimulation with various microbial stimuli. Dietary intake of yWGP for 2 weeks at concentrations of 1% and 2.5% w/w increases ex vivo cytokine production in mouse blood and bone marrow, whereas 5% w/w yWGP shows no effect. In the spleen, cytokine production remains unaffected by yWGP. At a concentration of 1% w/w, rice bran‐1 increases ex vivo cytokine production by whole blood, but 2.5% and 5% w/w cause inhibitory effects in bone marrow and spleen. This study demonstrates that dietary yWGP and rice bran‐1 induce immune priming in mouse blood and bone marrow, with the strongest effects observed at 1% w/w. Future human trials should substantiate the efficacy of dietary β‐glucans and arabinoxylans to bolster host immunity, focusing on dose optimization. Consuming yeast‐derived whole β‐glucan particle (yWGP) and rice‐derived arabinoxylan (rice bran‐1) at 1% and 2.5% weight/weight for 2 weeks increases ex vivo cytokine production in mouse blood and bone marrow, while spleen cytokine levels show no significant increase post‐stimulation with microbial stimuli. This study demonstrates dietary yWGP and rice bran‐1 induce innate immune priming in mouse blood and bone marrow.