Serum peptide barcode and peptidome profile of horses with Equine Gastric Ulcer Syndrome

Early and accurate diagnosis of Equine Gastric Ulcer Syndrome (EGUS) is critical for effective treatment and management. This study aimed to analyse the serum peptide barcode and peptidome profile of horses with EGUS using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and liquid chromatography-tandem mass spectrometry. The study included 64 pure bred and mixed Thoroughbred horses. Serum samples were collected from horses diagnosed with EGUS and analysed using MALDI-TOF MS to detect peptide barcodes. LC-MS/MS was employed to further identify and quantify specific peptidome profiles. Results revealed groups of horses according to total scores from the gastroscopic finding: survey normal, survey mild and survey severe with 36, 14 and 14 horse in each group. Distinct peptide profiles in horses with EGUS compared to healthy controls, with several peptides demonstrating significant differences in abundance. Peptide barcodes also revealed differences in patterns among groups. LC-MS analysis revealed distinct peptide biomarker profiles across severity, identifying 48, 25 and 35 unique peptides for survey normal, mild, and severe groups, respectively. These peptides were associated with gastrointestinal tissue integrity, inflammatory responses, and mucosal repair, providing insights into the pathophysiology underlying EGUS. The integration of both techniques proved effective in identifying potential biomarkers for non-invasive EGUS diagnosis.