Diets supplemented with protein and fiber are well known to reduce food intake and weight gain; however, less is known about the combined effects of protein and prebiotic fiber on energy balance and gut microbiota composition. We compared effects of diets containing high egg or whey protein with cellulose or prebiotic (inulin) fiber on energy balance, gut microbiota, hormones, and metabolites. Male obese rats (8/group) were allocated to four diets: Egg albumen+Cellulose (EC), Egg albumen+Inulin (EI), Whey protein+Cellulose (WC), and Whey protein+Inulin (WI). Results revealed that diet-induced hypophagia was transient with EC and prolonged with EI and WI, compared to WC. Importantly, CCK-1 receptor antagonist (Devazepide) attenuated the hypophagic effects of EC, EI, and WI. Further, EC, EI and WI decreased respiratory quotient, energy expenditure, weight and adiposity gains, and improved glycemia, relative to WC. Propranolol (β-β-receptor blocker) attenuated diet-induced changes in energy expenditure. Transcript abundance of thermogenic markers in brown adipose tissue, plasma hormones, and metabolites especially acyl-carnitines and glycerophospholipids, were differentially altered by diets. Diet explained 25% of compositional differences in cecal microbiomes, but diets with same fiber type did not differ. Microbiota differing between groups also strongly correlated with gut hormones and metabolites. Species most strongly correlated to a marker for butyrate production were in highest abundance in inulin diets. Together, these findings indicate that inulin enriched diets containing egg or whey protein improved energy balance, decreased adiposity, and modulated gut microbiota and metabolites, with CCK signaling partly mediating the satiety effects of diets.

中文翻译：

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膳食乳清和鸡蛋蛋白与菊粉纤维相互作用，调节肥胖大鼠的能量平衡和肠道微生物群


众所周知，补充蛋白质和纤维的饮食可以减少食物摄入和体重增加；然而，人们对蛋白质和益生元纤维对能量平衡和肠道微生物群组成的综​​合影响知之甚少。我们比较了含有高鸡蛋或乳清蛋白与纤维素或益生元（菊粉）纤维的饮食对能量平衡、肠道微生物群、激素和代谢物的影响。雄性肥胖大鼠（8只/组）被分配到四种饮食：蛋清+纤维素（EC）、蛋清+菊粉（EI）、乳清蛋白+纤维素（WC）和乳清蛋白+菊粉（WI）。结果显示，与 WC 相比，饮食引起的吞咽不足在 EC 中是短暂的，而在 EI 和 WI 中则延长。重要的是，CCK-1 受体拮抗剂（Devazepide）减弱了 EC、EI 和 WI 的食欲减退作用。此外，相对于 WC，EC、EI 和 WI 降低了呼吸商、能量消耗、体重和脂肪增加，并改善了血糖。普萘洛尔（β-β-受体阻滞剂）可减弱饮食引起的能量消耗变化。棕色脂肪组织、血浆激素和代谢物（尤其是酰基肉碱和甘油磷脂）中产热标记物的转录丰度因饮食而发生差异性改变。饮食解释了盲肠微生物组 25% 的组成差异，但具有相同纤维类型的饮食没有差异。不同群体之间的微生物群差异也与肠道激素和代谢物密切相关。与丁酸盐生产标记物密切相关的物种在菊粉饮食中的丰度最高。总之，这些发现表明，含有鸡蛋或乳清蛋白的富含菊粉的饮食可以改善能量平衡，减少肥胖，并调节肠道微生物群和代谢物，CCK 信号在一定程度上介导饮食的饱腹感效果。