Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, AB, Canada T2N 4N1.
Department of Animal Science, Oklahoma State University, Stillwater, OK 74078, USA.
J Nutr Biochem. 2018 Sep;59:142-152. doi: 10.1016/j.jnutbio.2018.05.017. Epub 2018 Jun 12.
Inulin, a popular prebiotic fiber, has been reported to promote satiety and fat loss; however, the dose-response effects of inulin on energy balance and diet preference, and whether the metabolic effects are independent of calorie restriction are not well characterized. Therefore, we compared the effects of diets varying in inulin concentrations on food intake, energy expenditure, body composition, gut microbiota and hormones, and assessed whether inulin-induced hypophagia was due to reduced diet preference. In experiment 1, male rats were randomized to six high-fat diet groups: control (CON, 0% inulin), 2.5% inulin (2.5IN), 10% inulin (10IN), 25% inulin (25IN), 25% cellulose (25CE) or pair-fed to 25IN (25PF) for 21 days. We demonstrate that inulin dose-dependently decreased caloric intake and respiratory quotient; improved glucose tolerance; increased the abundance of Bacteroidetes and Bifidobacterium spp.; decreased Clostridium clusters I and IV; increased butyryl-CoA:acetate CoA-transferase in cecum; upregulated peptide YY, cholecystokinin and proglucagon transcripts in the cecum and colon; and increased plasma peptide YY and glucagon-like peptide-1 concentrations. Importantly, unlike 25PF, 25IN attenuated the reduction in energy expenditure associated with calorie restriction and decreased adiposity. In experiment 2, following four training periods, diet preferences were determined. Although 10IN and 25IN decreased caloric intake, and 25CE increased caloric intake, during training, all high-fiber diets were less preferred. Taken together, this work demonstrates that inulin dose-dependently decreased caloric intake, modulated gut microbiota and upregulated satiety hormones, with metabolic effects being largely independent of caloric restriction.
菊粉是一种常用的益生元纤维，已被报道可促进饱腹感和减脂；然而，菊粉对能量平衡和饮食偏好的剂量反应效应，以及这些代谢效应是否独立于热量限制，尚未得到很好的描述。因此，我们比较了不同菊粉浓度的饮食对食物摄入、能量消耗、身体成分、肠道微生物群和激素的影响，并评估了菊粉诱导的摄食量减少是否是由于饮食偏好降低所致。在实验 1 中，雄性大鼠随机分为六组高脂肪饮食组：对照组（CON，0%菊粉）、2.5%菊粉（2.5IN）、10%菊粉（10IN）、25%菊粉（25IN）、25%纤维素（25CE）或按 25IN 量进行等热量喂养（25PF）21 天。我们证明了菊粉剂量依赖性地降低了热量摄入和呼吸商；改善了葡萄糖耐量；增加了拟杆菌门和双歧杆菌属的丰度；减少了梭菌簇 I 和 IV；增加了盲肠中的丁酰 CoA：乙酰 CoA 转移酶；上调了盲肠和结肠中的肽 YY、胆囊收缩素和胰高血糖素前体转录物；并增加了血浆肽 YY 和胰高血糖素样肽-1 浓度。重要的是，与 25PF 不同，25IN 减弱了与热量限制相关的能量消耗减少，并降低了肥胖度。在实验 2 中，经过四个训练期，确定了饮食偏好。尽管 10IN 和 25IN 降低了热量摄入，25CE 增加了热量摄入，但在训练期间，所有高纤维饮食的偏好度都较低。总之，这项工作表明，菊粉剂量依赖性地降低了热量摄入，调节了肠道微生物群并上调了饱腹感激素，其代谢效应在很大程度上独立于热量限制。
