The effect of micronized corn fiber on body weight, glycemia, and lipid metabolism in rats fed cafeteria diet

Abstract During corn industrial dry milling, a residue rich in dietary fibers is generated. This study aimed to evaluate the effects of micronized corn fiber (MCF) as part of a cafeteria diet in the macronutrient metabolism and body weight. Wistar male rats, with initial body weight of 249 ± 14 g (n = 13), received AIN-93M diet (Group 1) or cafeteria diet (Groups 2, 3 and 4), composed of commercial ration, cookies, fried potato sticks, milk chocolate, bacon and chicken liver pâté. Groups 3 and 4 received MCF to replace 100 and 50% of the cellulose from the AIN-93M diet, respectively. After 35 days, blood, tissues and feces were collected. Data were analyzed by ANOVA followed by Tukey test (p < 0.10). The weight gain of the animals increased by 25.9%, 20.8% and 22.0%, when fed cafeteria diet or 100 and 50% of MCF respectively, compared to the control group, although food consumption did not differ between them. Body weight and food efficiency ratio did not differ between the groups fed cafeteria diet with or without MCF. The addition of MCF to the cafeteria diet did not alter the animal lipid profile and glycemia, however, the accumulation of lipids in their livers was similar to the control group. The intake of 100% MCF resulted in higher fecal weight and fecal excretion of lipids, and lower fecal nitrogen, lipid absorption and lipid deposition in the liver than the cafeteria diet. In conclusion, MCF has a potential to improve intestinal transit and lipid excretion, but showed no benefit on blood lipid and glucose levels.

摘要 玉米工业干法磨粉过程中会产生富含膳食纤维的副产物。本研究旨在评估微细化玉米纤维（micronized corn fiber, MCF）作为自助餐饮食谱的组成部分，对宏量营养素代谢及体质量的影响。选取初始体质量为249±14 g的雄性Wistar大鼠共13只，分别饲喂AIN-93M标准饲料（第1组）或自助餐饮食谱（第2、3、4组），后者由商业标准饲料、曲奇饼干、炸薯条、牛奶巧克力、培根及鸡肝酱组成。第3组和第4组分别以MCF替代AIN-93M饲料中100%和50%的纤维素。饲养35天后，采集血液、组织及粪便样本。数据采用单因素方差分析（ANOVA）及Tukey多重比较检验进行分析，检验水准设为p<0.10。与对照组相比，饲喂自助餐饮食谱、100%MCF替代组及50%MCF替代组的大鼠体质量增重分别升高25.9%、20.8%和22.0%，但各组间食物摄入量无显著差异。饲喂含或不含MCF的自助餐饮食谱的各组间，体质量及食物效率比无显著差异。在自助餐饮食谱中添加MCF并未改变大鼠的血脂谱及血糖水平，但肝脏脂质蓄积量与对照组相近。与单纯自助餐饮食谱组相比，100%MCF替代组的粪便质量、粪便脂质排泄量更高，而粪便氮含量、脂质吸收率及肝脏脂质沉积量更低。综上，MCF可改善肠道转运功能并促进脂质排泄，但对血脂及血糖水平无显著益处。