ABSTRACT
AIMS: To explore how fermented barley extracts could affect obesity-associated inflammatory responses to ameliorate high-fat diet (HFD)-induced obesity, and investigate whether their anti-inflammatory properties were affected by modulating the gut microbiota. METHODS AND RESULTS: Twenty-four male rats were assigned randomly to three groups for 8 weeks. Inflammatory status and gut microbiota in HFD-induced obese rats were measured by enzyme linked immunosorbent assay and 16sRNA sequencing technology. The dietary supplementation of Extract of fermented barley with L. plantarum JDM1 (LFBE) reduced HFD-induced obesity and improved insulin sensitivity. LFBE significantly decreased the levels of lipopolysaccharide (LPS) and pro-inflammatory cytokines (tumour necrosis factor-α, interleukin [IL]-6, IL-1ß, monocyte chemotactic protein-1), and increased anti-inflammatory cytokines (IL-10) in serum. In addition, LFBE suppressed the activation of nuclear factor-κB (NF-κB) by inhibiting the inhibitor of NF-κB alpha degradation and phosphorylation of JNK/p38 mitogen-activated protein kinases in adipose tissue. Combined with changes in gut microbiota, these results illustrated that LFBE treatment markedly decreased the proportion of the LPS-producing opportunistic pathogens and increased the proportion of Bifidobacterium. CONCLUSIONS: Administration of LFBE has beneficial effects on ameliorating HFD-induced obesity and insulin resistance, lessening HFD-induced gut microbiota dysbiosis and pro-inflammatory cytokines secretion. SIGNIFICANCE AND IMPACT OF THIS STUDY: The results suggest that fermented barley extracts may be a useful functional compound and beneficial to improve inflammatory status and gut microflora.