Unveiling Cell-Type-Specific Immune Reactions in Human Blood Following Varied Fruit and Vegetable Blends Interventions

A diet rich in fruits and vegetables (F&Vs) reduces chronic disease risk by modulating oxidative stress, inflammatory cytokines, and immune cell activity in the blood. Given the complexity of peripheral blood and its cellular components, understanding cell-type-specific responses to F&V interventions remains essential and challenging. We used CIBERSORTx to analyze immune cell fractions and gene expression profiles from RNA sequencing data of the MiBLEND study, which assessed the impact of seven F&V blends on chronic disease markers, phytochemical absorption, and gene expression changes in blood. Analysis of white blood cells (WBCs) showed no significant changes in proportions of major leukocyte types. CIBERSORTx determined proportions of 22 leukocyte subtypes, correlating with traditional WBC composition. Paired t tests revealed that blends higher in carotenoids, anthocyanins, or complex phytochemicals altered CD4+/CD8+ T cell ratios. A strong positive association was observed between the proportion of memory B cells and beta-carotene levels in peripheral blood following the consumption of Blend 1. Finally, DEGs and pathway analyses showed that some blends affected DNA repair in B cells, NF-kappa B signaling in plasma cells, and endocytosis in dendritic cells (DCs) and natural killer (NK) cells. These findings offer clearer insight into immune cell dynamics in blood following F&V interventions, clarifying immune mechanisms involved in their preventive effects.