Wheat bran oil ameliorates high-fat diet-induced obesity in rats with alterations in gut microbiota and liver metabolite profile.

Background: Obesity is one of the public health issues that seriously threatens human health. This study aimed to investigate the effects of wheat bran oil (WBO) on body weight and fat/lipid accumulation in high-fat diet (HFD)-induced obese rats and further explore the possible mechanisms by microbiome and metabolome analyses.

Methods: Fifty Sprague-Dawley (SD) rats were fed either a normal chow diet (B group, n = 10) or HFD (n = 40) for 14 weeks to establish an obesity model. The HFD-induced obese rats were further divided into four groups and given WBO at 0 mL/kg (M group), 1.25 mL/kg (WBO-L group), 2.5 mL/kg (WBO-M group), and 5 mL/kg (WBO-H group) by oral gavage for 9 weeks. The body weight of rats was weighed weekly. The gut microbiota structure was analyzed using 16 S rDNA high-throughput sequencing. The liver metabolite profile was determined using UHPLC-QE-MS non-target metabolomics technology.

Results: In this study, WBO treatment reduced body weight gain, fat and lipid accumulation, and ameliorated hepatic steatosis and inflammation. WBO treatment increased the relative abundance of Romboutsia and Allobaculum and decreased that of Candidatus_Saccharimonas, Alloprevotella, Rikenellaceae_RC9_gut_group, Alistipes, Parabacteroides, UCG-005, Helicobacter, Colidextribacter, and Parasutterella compared with the M group. A total of 22 liver metabolites were significantly altered by WBO treatment, which were mainly involved in taurine and hypotaurine metabolism, nicotinate and nicotunamide metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, phenylalanine metabolism, and ether lipid metabolism.

Conclusions: WBO alleviated body weight gain and fat/lipid accumulation in HFD-induced obese rats, which may be related to altered gut microbiota and liver metabolites.