Australian Research Council, Centre of Excellence in Plant Cell Walls, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, Australia.
Apex Biometry, South Fremantle, Australia.
Eur J Nutr. 2021 Oct;60(7):4001-4017. doi: 10.1007/s00394-021-02567-3. Epub 2021 May 5.
The combined effects of grain digestibility and dietary fibre on digesta passage rate and satiety in humans are poorly understood. Satiety can be increased through gastric distention, reduced gastric emptying rate and when partially digested nutrients reach the terminal ileum to stimulate peptide release through the ileal/colonic brakes to slow the rate of digesta passage. This study determined the effects of grain digestibility and insoluble fibre on mean retention time (MRT) of digesta from mouth-to-ileum, feed intake (FI), starch digestion to the terminal ileum and faecal short chain fatty acids (SCFA) in a pig model.
Twelve grain-based [milled sorghum (MS), steam-flaked-sorghum, milled wheat, and steam-flaked-wheat (SFW)] diets with different intrinsic rates of starch digestion, assessed by apparent amylase diffusion coefficient (ADC), and fibre from oat hulls (OH) at 0, 5 and 20% of the diet were fed to ileal-cannulated pigs.
MRT was affected by grain-type/processing (P < 0.05) and fibre amount (P < 0.05). An approximate tenfold increase in ADC showed a limited decline in MRT (P = 0.18). OH at 20% increased MRT (P < 0.05) and reduced FI (P < 0.05). Ileal digestibility of starch increased and faecal SCFA concentration decreased with ADC; values for MS being lower (P < 0.001) and higher (P < 0.05), respectively, than for SFW.
Lower ileal digestibility of starch, higher faecal SCFA concentration and longer MRT of MS than SFW, suggest the ileal/colonic brakes may be operating. FI appeared to decrease with increasing MRT. MRT increased and intake decreased with grain-based foods/feeds that have low starch digestibility and substantial amounts of insoluble fibre.
谷物消化率和膳食纤维对人类食糜通过率和饱腹感的综合影响尚不清楚。饱腹感可以通过胃扩张、降低胃排空率以及部分消化的营养物质到达回肠末端来刺激肽释放来实现，通过回肠/结肠制动器减缓食糜通过率。本研究旨在确定谷物消化率和不溶性纤维对食糜从口腔到回肠的平均停留时间（MRT）、采食量（FI）、淀粉消化到回肠末端以及粪便短链脂肪酸（SCFA）的影响在猪模型中。
将 12 种基于谷物的[碾磨高粱（MS）、蒸汽膨化高粱、碾磨小麦和蒸汽膨化小麦（SFW）]日粮，用表观淀粉酶扩散系数（ADC）评估其内在淀粉消化率，以及日粮中 oat hulls（OH）0、5 和 20%的纤维，喂给回肠可结扎的猪。
MRT 受到谷物类型/加工（P<0.05）和纤维量（P<0.05）的影响。ADC 增加约十倍，MRT 略有下降（P=0.18）。20%的 OH 增加了 MRT（P<0.05）并降低了 FI（P<0.05）。淀粉在回肠中的消化率增加，粪便 SCFA 浓度降低与 ADC 相关；MS 的数值较低（P<0.001），而 SFW 的数值较高（P<0.05）。
MS 比 SFW 的淀粉在回肠中的消化率较低、粪便 SCFA 浓度较高、MRT 较长，提示回肠/结肠制动器可能在起作用。随着 MRT 的增加，FI 似乎减少。随着具有低淀粉消化率和大量不溶性纤维的谷物基食物/饲料的增加，MRT 增加，摄入量减少。
