High-protein and high-carbohydrate breakfasts differentially change the transcriptome of human blood cells

Background: Application of transcriptomics technology in human nutrition intervention studies would allow for genome-wide screening of the effects of specific diets or nutrients and result in biomarker profiles. Objective: The aim was to evaluate the potential of gene expression profiling in blood cells collected in a human intervention study that investigated the effect of a high-carbohydrate (HC) or a high-protein (HP) breakfast on satiety. Design: Blood samples were taken from 8 healthy men before and 2 It after consumption of an HP or an HC breakfast. Both breakfasts contained acetaminophen for measuring the gastric emptying rate. Analysis of the transcriptome data focused on the effects of the HP or HC breakfast and of acetaminophen on blood leukocyte gene expression profiles. Results: Breakfast consumption resulted in differentially expressed genes, 317 for the HC breakfast and 919 for the HP breakfast. Immune response and signal transduction, specifically T cell receptor signaling and nuclear transcription factor kappa B signaling, were the overrepresented functional groups in the set of 141 genes that were differentially expressed in response to both breakfasts. Consumption of the HC breakfast resulted in differential expression of glycogen metabolism genes, and consumption of the HP breakfast resulted in differential expression of genes involved in protein biosynthesis. Conclusions: Gene expression changes in blood leukocytes corresponded with and may be related to the difference in macronutrient content of the breakfast, meal consumption as such, and acetaminophen exposure. This study illustrates the potential of gene expression profiling in blood to study the effects of dietary exposure in human intervention studies.