Inulin from Jerusalem artichoke tubers alleviates hyperglycaemia in high-fat-diet-induced diabetes mice through the intestinal microflora improvement

The rate of hyperglycaemia in people around the world is increasing at an alarming rate at present, and innovative methods of alleviating hyperglycaemia are needed. The effects of Jerusalem artichoke inulin on hyperglycaemia, liver-related genes and the intestinal microbiota in mice fed a high-fat diet (HFD) and treated with streptozotocin (STZ) to induce hyperglycaemia were investigated. Inulin-treated hyperglycaemic mice had decreased average daily food consumption, body weight, average daily water consumption and relative liver weight and blood concentrations of TAG, total cholesterol, HDL-cholesterol and fasting blood glucose. Liver-related gene expressions in hyperglycaemic (HFD-fed and STZ-treated) compared with control mice showed eighty-four differentially expressed genes (forty-nine up-regulated and thirty-five down-regulated). In contrast, hyperglycaemic mice treated with inulin had twenty-two differentially expressed genes compared with control ones. Using Illumina high-throughput sequencing technology, the rarefaction and the rank abundance curves as well as the α diversity indices showed the treatment-induced differences in bacterial diversity in intestine. The linear discriminant analysis of effect size showed that the inulin treatment improved intestinal microbiota; in particular, it significantly increased the number of Bacteroides in the intestine of mice. In conclusion, inulin is potentially an effective functional food for the prevention and/or treatment of hyperglycaemia.