Validation of the Dual-isotope Method for Measuring Ileal Protein Digestibility
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 入组人数
- 36
- 试验地点
- 2
- 主要终点
- Real ileal amino acid digestibility
研究概览
简要总结
The dual isotope method has been recently developed and used to evaluate indispensable amino acid (IAA) digestibility of various protein food such as legumes, eggs and chicken meat in healthy adults and children. The dual isotope method is an indirect method based on the measurement in plasma of absorbed IAA from a deuterium (2H) intrinsically labeled test protein compared against the same IAA of a carbon 13 (13C) intrinsically labeled standard protein of known digestibility or crystalline amino acids (AA) of theoretical 100% digestibility. However, digestibility data estimated with the dual isotope method have not been directly compared with ileal IAA digestibility directly determined through ileal digesta sampling. The goal of this study is to assess the IAA digestibility of intrinsically 2H-hen's egg in healthy volunteers using both indirect and direct methods.
详细描述
The test meal will consist of 60 g of lyophilized whole egg powder which contains 30 g of 2H-egg protein and 800 mg [U-13C]-spirulina or 400 mg of 13C free AA mixture, mixed with water and cooked as an omelet. The 2H-egg powder has been produced by our collaborators of the St John's Research Institute in Bangalore (India). Celite (acid insoluble ash, Advanced Minerals Corporation) will be added to the meal as an indigestible marker to check the recovery of the meal in effluents. The test-meal will be given as a bolus or in a plateau feeding (repeated mini-meals) depending of the groups of subjects. 600 g of 2H-labeled lyophilized eggs will be obtained from layer hens administered a uniformly 2H-labeled AA mix orally for 60 d with their daily feed. Microbiological analyses will be performed to ensure their safety for human consumption.
18 volunteers will be included at the end of the study and tested at the Human Nutrition Research Centre of Avicenne Hospital (France). The main inclusion criteria are men and women, 18 to 45 year-old, body mass index (BMI) 18 to 30 kg/m2. The main exclusion criteria are any digestive or hepatic pathology, allergy against eggs, allergy against latex, pregnant women. Due to the invasive procedure of intubation, the investigators plan to recruit 30 volunteers to accommodate for the usual 40% dropouts.
The subjects will be divided in 3 groups of n = 6:
- Bolus-spi, n = 6, the volunteers will consume the test-meal as a bolus in one time at t = 0, with 13C-spirulina as the reference protein
- Plateau-spi, n = 6, the volunteers will consume the test-meal in a plateau feeding protocol, with 13C-spirulina as the reference protein
- Plateau-AA, n = 6, the volunteers will consume the test-meal in a plateau feeding protocol, with 13C-free AA mixture as the reference "protein"
One week before the experiment, the volunteers will follow a standard diet adapted to their body weight to control their protein intake (1.3 g protein/kg body weight).
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 45 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •18<BMI<30
- •Insured under the French social security system
- •For women: use of birth control
- •Signed informed consent
排除标准
- •Any dietary allergy
- •Latex allergy
- •Positive serology to HIV, hepatite C virus antibody, hepatite B virus surface antigen and core antibodies
- •Gluten intolerance
- •Use of drugs
- •High consumption of alcohol
- •Hypertension, diabetes, digestive disease, hepatic or renal disease, severe cardiac disease
- •Pregnancy
- •High sport practicing (>7h/wk)
- •Blood donation in the 3 months prior to the study
- •Participation in a clinical study in the 3 months prior to the study
- •No signed informed consent
研究组 & 干预措施
Bolus-spi
The volunteers will consume the test-meal as a bolus in one time at t = 0, with 13C-spirulina as the reference protein
干预措施: Dual isotope method (Other)
Plateau-spi
The volunteers will consume the test-meal in a plateau feeding protocol, with 13C-spirulina as the reference protein
干预措施: Dual isotope method (Other)
Plateau-AA
The volunteers will consume the test-meal in a plateau feeding protocol, with 13C-free AA mixture as the reference "protein"
干预措施: Dual isotope method (Other)
结局指标
主要结局
Real ileal amino acid digestibility
时间窗: -30 minute to 8 hours after the first meal
The measurements of amino acid concentration (mmol) and their individual 2H enrichment (atom %) allow the determination of dietary amino acids remaining in the lumen. Dietary amino acids that are recovered in the ileal samples are then considered as non absorbed and expressed as % of amino acid ingested, it allows the calculation of real ileal amino acid digestibility (100 - dietary amino acid not absorbed)
Indirect amino acid digestibility
时间窗: -30 minute to 8 hours after the first meal
The individual amino acid 2H enrichment (atom %) and 13C enrichment (atom %) in the meal and in the plasma from 5 h to 8 h or 0 h to 8 h after the first meal (depending of the group) will be evaluated to calculate their ratio: Ratio meal AAi = 2H meal AAi / 13C meal AAi Ratio plasma AAi = 2H plasma AAi / 13C plasma AAi The ratio of the meal and plasma ratios will be corrected by the known digestibility of spirulina amino acid or free amino acid (in %, depending of the group) to determine the indirect amino acid digestibility of lyophilized egg protein with the following formula: Indirect ileal amino acid digestibility (%) = AAi ileal digestibility spirulina or free AA mix (%) x Ratio plasma AAi / Ratio meal AAi
次要结局
- Urinary, fecal and plasma individual amino acid concentration in response to protein ingestion(-30 minute to 8 hours after the first meal)
- Gut microbiota in response to protein ingestion(Before and 24 hours after meal intake)
- Plasma, urinary and fecal peptidome in response to protein ingestion(-30 minute to 8 hours after the first meal)
研究者
Robert Benamouzig
Professor
Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement