Fermented barley extracts with Lactobacillus plantarum dy-1 decreased fat accumulation of Caenorhabditis elegans in a daf-2-dependent mechanism.

Abstract

Barley, a kind of cereal, is rich in polysaccharides, phenols, proteins, β-glucan, etc. Our previous studies discovered that extracts from Lactobacillus plantarum dy-1-fermented barley (LFBE) held strong anti-obesity property in obese rats through inhibiting inflammation and suppressing the differentiation in 3T3-L1 preadipocytes; however, the precise mechanism of LFBE regulating lipid metabolism remains elusive. Results suggested LFBE and its main active components, especially the total phenols, exhibited fat-lowering effects in glucose treated Caenorhabditis elegans at a certain concentration. Additionally, LFBE and the main components changed related genes in the insulin signaling pathway, fatty acid oxidation, and synthesis. Following verification study using mutants confirmed that the daf-2 gene rather than the daf-16 gene was required in LFBE and main components regulating lipid metabolism, which also involved in the process of fatty acid β-oxidation and unsaturated fatty acid synthesis. Results demonstrated that LFBE and its main bioactivate compounds inhibited fat accumulation partly in a daf-2-dependent mechanism. PRACTICAL APPLICATIONS: Our previous studies have reported that extracts of fermented barley exhibited anti-obesity activity. However, little is known about which functional factors play a leading role in decreasing fat deposition and its precise mechanism. Results indicated that daf-2 mediated signaling pathways involved in the fat-lowering effects of LFBE and its main components. Our findings are beneficial to understand the main nutritional ingredients in LFBE which are ideal and expected in functional foods for the obese.