Development and Validation of a Targeted Analytical Method for the Quantification of Primary and Secondary Bile Acids by LC-MS/MS: Profile in Obesity

• Grant number: 25/02042-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2025
• End date: March 31, 2026
• Field of knowledge: Biological Sciences - Biochemistry - Chemistry of Macromolecules
• Principal Investigator: Carlos Arterio Sorgi
• Grantee: Luiz Felipe Marques Rodrigues
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Bile acids (BAs) play fundamental role in digestion and lipid metabolism, being involved in the regulation of cholesterol homeostasis. Alterations in their concentrations may be associated with metabolic diseases such as obesity and type 2 diabetes, acting as cellular signaling mediators and inflammation modulators. However, the quantification of these lipids presents challenges, mainly due to the presence of structural isomers and microbial-conjugated bile acids (MCBAs), making advanced analytical methods necessary for reliable identification. Therefore, our study is justified by the limitations of current analytical methods in the validation and quantification of BA metabolites, which compromise the accuracy of clinical results. Our objective is to use high-resolution mass spectrometry (LC-MS/MS) with the advanced ZenoTOF 7600 system to efficiently differentiate isomers through Electron-Activated Dissociation (EAD) fragmentation studies and provide a detailed profile of BAs in human plasma samples. This methodology will enable a more sensitive and robust analysis, essential for clinical studies related to BA regulation in obesity. To achieve this, we will validate the analytical method by assessing linearity, detection limits, accuracy, and precision. Additionally, we will evaluate recovery efficiency through the standardization of biological matrix extraction methods, employing protein precipitation and biphasic extraction techniques. Statistical analyses will be conducted to assess differences between obese and eutrophic individuals, identifying potential biomarkers associated with metabolic disorders. Our results may contribute to new therapeutic strategies for obesity and its comorbidities while driving advances in the bioanalytical and biotechnological fields related to BAs.