Evaluation of the effects of D-limonene supplementation and diet on the postprandial glycemic response: a clinical study developed remotely

Abstract

D-limonene, found mainly in orange peel, is associated with several beneficial properties, including hypolipidemic, hypoglycemic and antimicrobial effects. Bile acids are cholesterol-derived molecules that are involved in the emulsification of dietary lipids, in addition to having endocrine effects, with the potential to modulate the metabolism of lipids and carbohydrates. Their metabolism involves hepatic synthesis and biotransformations carried out by the intestinal microbiota, whose composition is sensitive to the host diet. The hypothesis of this study is that due to its antimicrobial activity D-limonene can modulate the intestinal microbiota, thus modulating the bile acid pool and glucose metabolism. Thus, the main objective of the present study is to evaluate the effects of supplementation with D-limonene on postprandial glucose metabolism in males and females. Volunteers will be supplemented with 2 g of D-limonene daily for 2 weeks. Before and after the supplementation period, a dietary challenge will be carried out at the study subjects' home in order to assess postprandial glycemic response to a mixed meal. Immediately before and after eating the meal (during 3 hours), blood glucose will be measured using a portable glucometer. Analysis of food consumption, assessment of the adequacy of diets, and postprandial glucose metabolism will be carried out. The results will allow an unprecedented analysis of the effects of D-limonene supplementation on glucose metabolism. As the study involves recruiting of research subjects remotely, it will not have its execution impacted by the COVID-19 pandemic and will serve, among other objectives, to assess the feasibility of a clinical study carried out remotely. (AU)