Lactobacillus plantarum NCU116 fermented carrot juice evokes changes of metabolites in serum from type 2 diabetic rats

•UPLC-Q-TOF/MS is a valuable tool for the analysis of metabolites in serum.•Eight potential biomarkers were identified by MPP software.•Biological pathways were affected by L. plantarum NCU116 fermented carrot juice.•Beneficial effects of fermented carrot juice on diabetic rats may be related to L. plantarum NCU116.

In this study, a novel metabolomics method based on ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry was developed to investigate the effect of Lactobacillus plantarum NCU116 (NCU116) fermented carrot juice on the metabolites of serum from high fat diet and streptozotocin-induced type 2 diabetic rats. Eight potential biomarkers (adenosine, proline, 5-hydroxyindoleacetaldehyde, glycocholic acid, taurochenodeoxycholic acid, sphingosine, theophylline and taurocholic acid) were identified by unpaired t test analysis, and the pathway features were analyzed by Mass Profiler Professional software. Clustering of partial least squares-discriminant analysis showed that biological pathways and processes, including metabolism of lipids, lipoproteins, purine, tryptophan, bile secretion, fatty acid biosynthesis, glycolysis and gluconeogenesis, were affected by NCU116 fermented carrot juice. These results suggest that metabolomics approach is very useful for studying the mechanisms of action of NCU116 supplement on type 2 diabetes.