The metabolic benefits of substituting sucrose for maple syrup are associated with a shift in carbohydrate digestion and gut microbiota composition in mice.

Abstract

Overconsumption of added sugars is now largely recognized as a major culprit in the global situation of obesity and metabolic disorders. Previous animal studies reported that maple syrup (MS) is less deleterious than refined sugars on glucose metabolism and hepatic health, but the mechanisms remain poorly studied. Beyond its content in sucrose, MS is a natural sweetener containing several bioactive compounds, such as polyphenols and inulin, which are potential gut microbiota modifiers. We aimed to investigate the impact of MS on metabolic health and gut microbiota in male C57Bl/6J mice fed a high-fat high-sucrose (HFHS+S) diet or an isocaloric HFHS diet in which a fraction (10% of the total caloric intake) of the sucrose was substituted by MS (HFHS+MS). Insulin and glucose tolerance tests were performed at 5 and 7 weeks into the diet respectively. Fecal microbiota was analyzed by whole-genome shotgun sequencing. Liver lipids and inflammation were determined, and hepatic gene expression was assessed by transcriptomic analysis. Maple syrup was less deleterious on insulin resistance and decreased liver steatosis compared to mice consuming sucrose. This could be explained by the decreased intestinal a-glucosidase activity, which is involved in carbohydrate digestion and absorption. Metagenomic shotgun sequencing analysis revealed that MS intake increased the abundance of Faecalibaculum rodentium, Romboutsia ilealis, and Lactobacillus johnsonii, which all possess gene clusters involved in carbohydrate metabolism, such as sucrose utilization and butyric acid production. Liver transcriptomic analyses revealed that the Cyp450 epoxygenase pathway was differently modulated between HFHS+S and HFHS+MS mice. These results show that substituting sucrose for MS alleviated dysmetabolism in diet-induced obese mice which were associated with decreased carbohydrate digestion and shifting gut microbiota.