Comprehensive assessment of the anti-obesity effects of highland barley total, insoluble, and soluble dietary fiber through multi-omics analysis

The impact of different forms of dietary fiber (total, insoluble or soluble) derived from the same source on health remains incompletely understood. In this study, the effects of total, insoluble, and soluble dietary fiber extracted from highland barley (HDF, HIDF, and HSDF) on combating obesity were evaluated and compared. A high-fat diet (HFD) was used to induce obesity in a murine model, followed by gavage administration of HDF, HIDF, or HSDF, and a comprehensive multi-omics approach was utilized to assess and compare the effects of these dietary fibers on obesity-related parameters. The results showed that all three dietary fibers significantly reduced body weight, modified blood lipid profiles, and ameliorated tissue damage in HFD-fed mice. Additionally, 16S rRNA sequencing analysis of mice feces showed that three types of dietary fiber exerted varying degrees of impact on the composition and abundance of gut microbiota while simultaneously promoting the biosynthesis of short-chain fatty acids. Specifically, HDF supplementation remarkably enhanced the abundance of Coprococcus, while HIDF and HSDF supplementation elevated the levels of Akkermansia and Allobaculum, respectively. Transcriptomic and proteomic results suggested the PPAR signaling pathway as a central regulatory mechanism influenced by these fibers. HDF and HIDF were particularly effective in modulating biological processes related to triglyceride and fatty acid metabolism, identifying Abcc3 and Dapk1 as potential targets. Conversely, HSDF primarily affected processes related to membrane lipids, ceramides, and phospholipids metabolism, with Pck1 identified as a potential target. Collectively, HDF, HIDF, and HSDF demonstrated distinct mechanisms in exerting exceptional anti-obesity properties. These insights may inform the development of personalized dietary interventions for obesity.