Comparative dietary profiling of smoked and non-smoked paprika (Capsicum annuum L.) in Wistar rats: metabolomic, biochemical and gut microbiota responses in a healthy animal model.

Paprika (Capsicum annuum L.) is a widely consumed spice whose bioactive composition is substantially influenced by processing conditions. Traditional smoking, as applied in the production of PDO Pimentón de la Vera, enriches paprika with wood smoke-derived phenolics while also introducing polycyclic aromatic hydrocarbons (PAHs), warranting an integrated evaluation of processing-related biological responses and safety considerations. This study compared physiological, biochemical, metabolomic, and cecal microbiota responses to dietary supplementation with smoked and non-smoked paprika in healthy Wistar rats. Thirty animals of both sexes (16 females and 14 males) received a control diet or diets supplemented with 5% smoked or non-smoked paprika for 30 days. Histological examination revealed no treatment-related alterations in the organs evaluated. Hematological and biochemical analyses showed diet- and sex-associated differences in hematocrit, plasma glucose, total antioxidant capacity, and lipid-related parameters, although all values remained within normal physiological ranges. Untargeted urinary metabolomics, restricted to males because of insufficient urine volume in females, identified features tentatively annotated as phenolic conjugates and other metabolites associated with paprika intake, with several signals showing higher abundance in the smoked paprika group. Cecal metagenomic analyses showed sex-dependent changes across taxon-level abundance, alpha diversity, and beta diversity. In females receiving smoked paprika, lower TC and LDL-C coincided with higher alpha diversity and lower cecal lipid content, suggesting a potential link between intestinal microbial ecology and lipid handling. Overall, paprika processing was associated with distinct biochemical, metabolomic, and cecal microbiota response patterns in this healthy animal model.