Fermented barley extracts with Lactobacillus plantarum dy-1 changes serum metabolomic profiles in rats with high-fat diet-induced obesity.

We have previously reported an aqueous extract of fermented barley with Lactobacillus plantarum dy-1 (LFBE) has more efficient anti-obesity effect compared with that of Saccharomyces cerevisiae. To further explore associated effects of LFBE on body weight and body fat distribution, and lipid profiles related metabolic outcomes, serum metabolites were analysed using LC-MS-MS and partial least-squares-discriminant analysis (PLS-DA). Obese and lean groups were clearly discriminated from each other on PLS-DA score plot and major metabolites contributing to the discrimination were assigned as lipid metabolites (fatty acids), lipid metabolism intermediates (choline, betaine, carnitine and butyryl-carnitine), amino acids and citric acid. A high-fat diet increased lipid metabolites and decreased lipid metabolism intermediates, indicating that abnormal lipid metabolism induced by a high-fat diet resulted in fat accumulation via decreased β-oxidation. But LFBE can inhibit fat accumulation by reducing lipid metabolites and increasing lipid metabolism intermediates. Furthermore, the level changes of these metabolites can be used to assess the risk of obesity and the therapeutic effect of obesity management.