Diet-responsive proteogenomic effects following short-term restriction of animal products in humans.

The effect of diet on genetic regulation in humans remains largely unexplored. Here, we investigate gene-diet interactions in a unique group of healthy individuals (N = 200) who alternate between omnivory and dietary restriction of animal products for religious reasons. Using longitudinal proteomic and genotype data, we identify diet-responsive cis-pQTLs and highlight regulatory effects on LBR and MSRA, proteins involved in cholesterol and methionine metabolism respectively. LBR-associated cis-pQTL rs74148404 colocalizes with obesity exclusively under dietary restriction, suggesting diet-dependent modulation of genetic risk. We also show that a diet-dependent cis-pQTL for metabolic regulator FGF21 colocalizes with eosinophil and platelet traits pointing to diet-sensitive immunometabolic signalling. By parallel profiling of a continuously omnivorous control group (N = 211), we uncover seasonally dynamic genetic regulation for proteins linked to apoptosis in immune system pathways (MAVS, CASP3, PDLIM7, IL12RB1), effects likely masked by animal product restriction. These findings reveal dynamic diet- and season-sensitive regulatory mechanisms with implications for precision nutrition and individualized disease prevention strategies, and underscore the need to integrate environmental context into genetic studies of health and disease.