Microbiota modulation by dietary oat beta-glucan prevents Non-alcoholic fatty liver disease progression
Background & Aims: Non-alcoholic fatty liver disease (NALFLD)-associated changes in gut microbiota are important drivers of disease progression toward fibrosis. Therefore, reversing microbiota alterations could ameliorate NAFLD progression. Oat beta-glucan, a non-digestible polysaccharides, has shown promising therapeutic effects on hyperlipidemia associated with NAFLD, but its impact on gut microbiota and most importantly NAFLD fibrosis remains unknown. Methods: We performed detailed metabolic phenotyping including body composition, glucose tolerance, and lipid metabolism as well as comprehensive characterization of the gut-liver axis in a western-style diet (WSD)-induced model of NAFLD and assessed the effect of a beta-glucan intervention on early and advanced liver disease. Gut microbiota was modulated using broad-spectrum antibiotic (Abx) treatment. Results: Oat beta-glucan supplementation did not affect WSD-induced body weight gain, glucose intolerance, and the metabolic phenotype remained largely unaffected. Interestingly, oat beta-glucan dampened NAFLD inflammation, associated with significantly reduced monocyte-derived macrophages (MoMFs) infiltration, fibroinflammatory gene expression, and strongly reduced fibrosis development. Mechanistically, this protective effect was not mediated by changes in bile acid composition or signaling, but was dependent on gut microbiota and was lost upon Abx treatment. Specifically, oat beta-glucan partially reversed unfavorable changes in gut microbiota, resulting in an expansion of protective taxa, including Ruminococcus, and Lactobacillus followed by reduced translocation of TLR ligands. Conclusions: Our findings identify oat beta-glucan as a highly efficacious food supplement that dampens inflammation and fibrosis development in diet-induced NAFLD. These results, along with its favorable dietary profile, suggest that it may be a cost-effective and well-tolerated approach to preventing NAFLD progression and should be assessed in clinical studies. Overall design: Comparative gene expression profiling analysis of RNA-seq data for liver tissue of male C57BL/6J mice.