Omnivores versus carnivores: Can higher levels of pulse starch be tolerated in a wider range of species than corn?

肉食性物种对碳水化合物的耐受性很差，而杂食性动物往往能耐受更高的饮食水平。然而，由于蛋白质通常是动物饲料中最昂贵的部分，最大限度地增加碳水化合物的数量可以产生更经济的饲料。为了平衡这些相互矛盾的需求，这项提议旨在探索使用缓慢消化的豆类淀粉(豌豆、扁豆、蚕豆)，而不是更标准的碳水化合物来源，如玉米淀粉。与玉米淀粉的快速消化和较高的血糖指数相比，豆类淀粉的消化较慢被认为会产生较低的血糖指数、较低的胰岛素水平和较少的不良健康影响。我们预测，与杂食性物种相比，使用豆类淀粉对健康的好处在肉食性物种中将特别明显。这一预测是基于这样一个事实，即肉食性物种的淀粉酶倾向于较低，预计葡萄糖从肠道运输到肝脏或肌肉的程度较小，从血流到肝脏或肌肉。据预测，与杂食性动物相比，由于关键的糖酵解酶水平较低，肉食性物种也会产生更高水平的反应性葡萄糖代谢物甲基乙二醛，这反过来又会导致更高水平的氧化应激和炎症。为了研究这些假说，我们将在长期喂养试验中比较肉食性物种猫和彩虹鲑鱼与杂食性物种狗和罗非鱼消化碳水化合物的能力、对单次喂养的血糖反应以及对健康的影响。此外，由于所有这些物种的饲料，包括宠物和水产养殖，通常以干颗粒形式出售，在充分发挥豆类的市场潜力之前，需要进一步了解挤压条件如何影响淀粉结构和消化率。有了这些新的、有科学依据的豆类营销信息，我们的行业合作伙伴将能够开拓新的水产养殖市场，并扩大现有的宠物食品市场，不仅在北美，而且在欧洲和亚洲。

Carbohydrates are poorly tolerated in carnivorous species, while omnivores tend to tolerate higher dietary levels. However, since protein is often the costliest portion of an animal feed, maximizing the amount of carbohydrate produces a more economical feed. In order to balance these contradictory needs, this proposal aims to explore the use of slowly digestible pulse starches (pea, lentil, faba bean) compared to a more standard carbohydrate source such as corn starch. The slower digestibility of pulse starches are hypothesized to produce lower glycemic index, lower insulin levels and fewer adverse health effects compared to the rapid digestibility and higher glycemic index of corn starch. We predict that the health benefits of using pulse starches will be particularly pronounced in carnivorous species compared to omnivorous species. This prediction is based on the fact that carnivorous species tend to have lower amylase and are predicted to transport glucose to a lesser extent, both from the intestine and disposal into liver or muscle from the bloodstream. Carnivorous species are also predicted to produce higher levels of the reactive glucose metabolite, methylglyoxal, due to lower levels of key glycolytic enzymes which will in turn lead to higher levels of oxidative stress and inflammation compared to omnivores. In order to investigate these hypotheses, we will compare the carnivorous species, cat and rainbow trout, to omnivorous species, dog and tilapia in their ability to digest carbohydrate, glycemic responses to single feedings and health effects in longer-term feeding trials. Furthermore, since feeds for all of these species, both pet and aquaculture, are usually sold in a dry pelleted form, further understanding of how extrusion conditions affect starch structure and digestibility is needed before the full marketing potential of pulses can be realized. With this new, scientifically-supported information for the marketing of pulses, our industry partners will be able open new aquaculture markets and expand existing pet food markets, not only in North America, but also in Europe and Asia.