Spetter Maartje S, Mars Monica, Viergever Max A, de Graaf Cees, Smeets Paul A M
Image Sciences Institute, University Medical Center Utrecht, Utrecht, the Netherlands.
Division of Human Nutrition, Wageningen University, Wageningen, the Netherlands.
Physiol Behav. 2014 Oct;137:9-17. doi: 10.1016/j.physbeh.2014.06.021. Epub 2014 Jul 4.
The interaction between oral and gastric signals is an important part of food intake regulation. Previous studies suggest that bypassing oral stimulation diminishes the suppression of hunger and increases gastric emptying rate. However, the role of appetite hormones, like cholecystokinin-8 and ghrelin, in this process is still unclear. Our objective was to determine the contributions of gastric and oral stimulation to subsequent appetite and hormone responses and their effect on ad libitum intake. Fourteen healthy male subjects (age 24.6±3.8y, BMI 22.3±1.6kg/m(2)) completed a randomized, single-blinded, cross-over experiment with 3 treatment-sessions: 1) Stomach distention: naso-gastric infusion of 500mL/0kJ water, 2) Stomach distention with caloric content: naso-gastric infusion of 500mL/1770kJ chocolate milk, and 3) Stomach distention with caloric content and oral exposure: oral administration of 500mL/1770kJ chocolate milk. Changes in appetite ratings and plasma glucose, insulin, cholecystokinin-8, and active and total ghrelin concentrations were measured at fixed time-points up to 30min after infusion or oral administration. Subsequently, subjects consumed an ad libitum buffet meal. Oral administration reduced appetite ratings more than both naso-gastric infusions (P<0.0001). Gastric infusion of a caloric load increased insulin and cholecystokinin-8 and decreased total ghrelin concentrations more than ingestion (all P<0.0001). No differences in active ghrelin response were observed between conditions. Ad libitum intake did not differ between oral and gastric administration of chocolate milk (P>0.05). Thus, gastric infusion of nutrients induces greater appetite hormone responses than ingestion does. These data provide novel and additional evidence that bypassing oral stimulation not only affects the appetite profile but also increases anorexigenic hormone responses, probably driven in part by faster gastric emptying. This confirms the idea that learned associations between sensory characteristics and associated metabolic consequences serve to adapt hormone responses to nutrient content. These findings underscore the importance of oral stimulation in the regulation of food intake.
口腔信号与胃信号之间的相互作用是食物摄入调节的重要组成部分。先前的研究表明，绕过口腔刺激会减弱饥饿抑制并提高胃排空率。然而，食欲激素，如胆囊收缩素 -8 和胃饥饿素，在这一过程中的作用仍不清楚。我们的目的是确定胃刺激和口腔刺激对后续食欲及激素反应的贡献，以及它们对随意进食量的影响。14 名健康男性受试者（年龄 24.6±3.8 岁，体重指数 22.3±1.6kg/m²）完成了一项随机、单盲、交叉实验，包括 3 个治疗阶段：1）胃扩张：经鼻胃管输注 500mL/0kJ 的水；2）含热量的胃扩张：经鼻胃管输注 500mL/1770kJ 的巧克力牛奶；3）含热量的胃扩张及口腔接触：口服 500mL/1770kJ 的巧克力牛奶。在输注或口服后长达 30 分钟的固定时间点测量食欲评分以及血浆葡萄糖、胰岛素、胆囊收缩素 -8 和活性及总胃饥饿素浓度的变化。随后，受试者自由进食一顿自助餐。口服比两种经鼻胃管输注更能降低食欲评分（P<0.0001）。与摄入相比，经胃输注热量负荷使胰岛素和胆囊收缩素 -8 增加，总胃饥饿素浓度降低更多（均 P<0.0001）。不同条件下活性胃饥饿素反应未观察到差异。巧克力牛奶口服和经胃给药后的随意进食量无差异（P>0.05）。因此，经胃输注营养物质比摄入引起更大的食欲激素反应。这些数据提供了新的额外证据，表明绕过口腔刺激不仅影响食欲特征，还会增加厌食激素反应，这可能部分是由更快的胃排空驱动的。这证实了这样一种观点，即感官特征与相关代谢后果之间的习得关联有助于使激素反应适应营养成分。这些发现强调了口腔刺激在食物摄入调节中的重要性。
