肠内营养配方蛋白质类型对胃内凝固的影响：磁共振随机对照研究的事后分析

　　导管喂养患者容易发生胃排空延迟，可导致反流、吸入性肺炎等并发症。不同类型的蛋白在胃内凝固的程度不同，胃排空时间不一。荷兰纽迪希亚高级医学营养、瑞士苏黎世大学医院、瑞士苏黎世联邦理工学院生物医学工程研究所招募21位志愿者，对P4混合蛋白质（乳清蛋白、酪蛋白、大豆蛋白、豌豆蛋白）和2种以酪蛋白为主的混合蛋白质进行比较，通过在磁共振（MRI）下进行动态观察，发现P4胃内凝固显著减少，胃排空速度增加。

JPEN J Parenter Enteral Nutr. 2016;40(4):134-135.

Effect of Protein Type in Enteral Nutrition Formulas on Coagulation in the Stomach In Vivo: Post Hoc Analyses of a Randomized Controlled Trial With MRI.

Marianne Klebach; Zandrie Hofman; Sena Bluemel; Jelena Curcic; Andreas Steingoetter.

Nutricia Advanced Medical Nutrition, Utrecht, Netherlands; University Hospital Zurich, Zurich, Switzerland; Institute for Biomedical Engineering, ETH Zurich, Zurich, Switzerland.

Purpose: Delayed gastric emptying is common in tube-fed patients. It is related to upper gastrointestinal complications, such as reflux and aspiration pneumonia, and reduced nutrition intake. Different types of protein have different gastric emptying times considered to be due to differences in coagulation of proteins in the stomach. In vitro digestion experiments have visualized the differences in coagulation, but no data are available in vivo. The current post hoc study investigated whether enteral formulas with different types of protein differ in coagulation in the human stomach as was previously demonstrated in vitro.

Methods: In a double-blind randomized 3-way crossover study in 21 healthy volunteers, 3 isocaloric (450 kcal) and isovolumetric (300 mL) enteral formulas—1 with a blend of 4 proteins (P4: whey, casein, soy, and pea) and 2 with casein-dominant protein blends (C1 and C2)—showed different gastric emptying rates (P4 > C1 and C2). In this post hoc analysis, coagulation in the stomach was investigated by visual inspection of the homogeneity in MR signal intensity. Intragastric MR signal inhomogeneity—that is, the presence of varying contrasts (dark and light spots) in the stomach—was used as a surrogate marker for coagulation. Signal inhomogeneity at 50, 65, and 80 minutes was rated by 3 persons unaware of the product sequence. Pairwise comparisons among the 3 products were performed with a McNemar test.

Results: For P4, C1, and C2, inhomogeneity was scored "yes" in, respectively, 10%, 89%, and 80% of the MRI scans (P4 vs C1, P = .0003; P4 vs C2, P = .0005; and C1 vs C2, P = .688). "No" was scored for 43%, 0%, and 10%, and "uncertain" was scored for 48%, 11%, and 10%.

Conclusions: The visual inspection of MR signal inhomogeneity in the stomach after intake of 3 protein-based enteral formulas indicated a lower degree of intragastric coagulation with the P4 protein blend as compared with casein-dominant enteral formulas. These results match with the differences in gastric emptying rate, validate in vitro findings, and support possible clinical benefits for tube-fed patients with gastrointestinal intolerance.

Financial support: The study was sponsored by Nutricia Research BV, Utrecht, Netherlands.