Ribeiro Gabriela, Fernandes Ana B, Oliveira Francisco P M, Duarte João S, Oliveira Manuela, Limbert Clotilde, Costa Rui M, Costa Durval C, Oliveira-Maia Albino J
Champalimaud Research & Clinical Centre, Champalimaud Foundation, Av. de Brasília, Doca de Pedrouços, Lisboa, Portugal.
Lisbon Academic Medical Centre PhD Program, Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, Lisboa, Portugal.
PLoS Biol. 2024 Dec 17;22(12):e3002936. doi: 10.1371/journal.pbio.3002936. eCollection 2024 Dec.
Postingestive nutrient stimulation conditions food preferences through striatal dopamine and may be associated with blunted brain responses in obesity. In a cross-sectional study, we tested flavor-nutrient conditioning (FNC) with maltodextrin-enriched yogurt, with maltodextrin previously optimized for concentration and dextrose equivalents (n = 57), and to mask texture cues (n = 102). After conditioning, healthy volunteers (n = 52) increased preference for maltodextrin-paired (+102 kcal, CS+), relative to control (+1.8 kcal, CS-) flavors, as assessed according to intake, but not pleasantness. In a clinical study (n = 61), behavioral conditioning without effects on pleasantness was confirmed across pre-bariatric candidates with obesity, weight-stable post-surgery patients, and healthy controls, without significant differences between groups. Striatal dopamine D2-like receptor (DD2lR) availability, assessed with [123I]IBZM SPECT, was reduced in the obesity group and strongly correlated with conditioning strength and a measure of restrained eating in patients with gastric bypass. These results show that postingestive nutrient stimulation influences human food choices through behavioral reinforcement, and is conserved in obesity and after bariatric surgery. Trial Registration: ISRCTN17965026: Dopaminergic neurotransmission in dietary learning and obesity.
摄食后营养刺激通过纹状体多巴胺影响食物偏好，且可能与肥胖患者大脑反应迟钝有关。在一项横断面研究中，我们用富含麦芽糊精的酸奶进行了风味-营养条件反射（FNC）实验，麦芽糊精的浓度和葡萄糖当量已预先优化（n = 57），并用于掩盖质地线索（n = 102）。条件反射后，根据摄入量评估，健康志愿者（n = 52）相对于对照风味（+1.8千卡，CS-），对与麦芽糊精配对的风味（+102千卡，CS+）的偏好增加，但愉悦感无变化。在一项临床研究（n = 61）中，对肥胖症患者、手术后体重稳定的患者和健康对照者进行了行为条件反射实验，结果证实对愉悦感无影响，且各组之间无显著差异。用[123I]IBZM单光子发射计算机断层扫描（SPECT）评估的纹状体多巴胺D2样受体（DD2lR）可用性在肥胖组中降低，且与条件反射强度以及胃旁路手术患者的抑制性饮食测量值密切相关。这些结果表明，摄食后营养刺激通过行为强化影响人类食物选择，且在肥胖症患者和减肥手术后依然存在。试验注册：ISRCTN17965026：饮食学习与肥胖中的多巴胺能神经传递。
