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 wk into the diet, respectively. The 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 with mice consuming sucrose. This could be explained by the decreased intestinal α-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 cytochrome P450 (Cyp450) epoxygenase pathway was differently modulated between HFHS + S- and HFHS + MS-fed 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.NEW & NOTEWORTHY The natural sweetener maple syrup has sparked much interest as an alternative to refined sugars. This study aimed to investigate whether the metabolic benefits of substituting sucrose with an equivalent dose of maple syrup could be linked to changes in gut microbiota composition and digestion of carbohydrates in obese mice. We demonstrated that maple syrup is less detrimental than sucrose on metabolic health and possesses a prebiotic-like activity through novel gut microbiota and liver mechanisms.
摘要：
现在，过量食用添加糖已被认为是全球肥胖和代谢紊乱状况的主要罪魁祸首。先前的动物研究报道，枫糖浆（MS）对葡萄糖代谢和肝脏健康的危害小于精制糖，但机制研究仍不充分。超出其在蔗糖中的含量，MS是一种含有几种生物活性化合物的天然甜味剂，如多酚和菊粉，它们是潜在的肠道微生物群调节剂。我们旨在研究MS对饲喂高脂高蔗糖（HFHSS）饮食或等热量HFHS饮食的雄性C57Bl/6J小鼠的代谢健康和肠道微生物群的影响，其中一部分（总热量摄入量的10％）蔗糖被MS（HFHSMS）代替。分别在饮食开始5周和7周进行胰岛素和葡萄糖耐量试验。通过全基因组鸟枪测序分析粪便微生物群。确定肝脏脂质和炎症，通过转录组学分析评估肝基因表达。与消耗蔗糖的小鼠相比，枫糖浆对胰岛素抵抗和肝脏脂肪变性的危害较小。这可以解释为肠道α-葡萄糖苷酶活性降低，参与碳水化合物的消化和吸收。宏基因组鸟枪测序分析显示，MS的摄入增加了鼠粪的丰度，回肠Romboutsia,和约翰森氏乳杆菌,它们都拥有参与碳水化合物代谢的基因簇，如蔗糖利用和丁酸生产。肝脏转录组学分析显示，Cyp450环氧合酶途径在HFHSS和HFHSMS小鼠之间受到不同的调节。这些结果表明，用蔗糖代替MS减轻了饮食诱导的肥胖小鼠的代谢异常，这与碳水化合物消化减少和肠道微生物群转移有关。
