A Low ω-6/ω-3 Ratio High-Fat Diet Improves Rat Metabolism via Purine and Tryptophan Metabolism in the Intestinal Tract, While Reversed by Inulin

A high-fat diet (HFD) is the main cause of metabolic diseases. However, HFD in previous studies consists of much lard, which contains a large amount of omega-6 (ω-6) polyunsaturated fatty acid (PUFA) and little omega-3 (ω-3) PUFA. The role of ω-6/ω-3 ratio of HFD in the development of metabolic diseases remains incompletely discussed. In this study, rats were fed with either a low or a high ω-6/ω-3 ratio HFD singly or combined with inulin. Metabolism state was valued and metabolomics of cecal content were detected. Results show that HFD with low ω-6/ω-3 ratio promotes the glucose utilization in rats. However, inulin had different effects on metabolism with different diets. Xanthosine and kynurenic acid in cecum were positively related to epididymal white adipose tissues (eWAT) mass. The present study indicates the beneficial effects of low ω-6/ω-3 ratio HFD (LRD) on the metabolic state of rats. Moreover, xanthosine and kynurenic acid were closely related to the development of metabolic diseases.