Instituto de Investigación en Ciencias de la Alimentación, CIAL (CSIC-UAM, CEI UAM+CSIC), Nicolás Cabrera, 9, 28049 Madrid, Spain.
Institut National de Recherche Pour l'Agriculture, l'Alimentation et l'Environnement (INRAE) STLO Agrocampus Ouest, 35042 Rennes, France.
Nutrients. 2023 Feb 21;15(5):1065. doi: 10.3390/nu15051065.
It is known that casein hydrolysis accelerates gastrointestinal transit in comparison to intact casein, although the effect of the protein hydrolysis on the composition of the digests is not fully understood. The aim of this work is to characterize, at the peptidome level, duodenal digests from pigs, as a model of human digestion, fed with micellar casein and a previously described casein hydrolysate. In addition, in parallel experiments, plasma amino acid levels were quantified. A slower transit of nitrogen to the duodenum was found when the animals received micellar casein. Duodenal digests from casein contained a wider range of peptide sizes and a higher number of peptides above five amino acids long in comparison with the digests from the hydrolysate. The peptide profile was markedly different, and although β-casomorphin-7 precursors were also found in hydrolysate samples, other opioid sequences were more abundant in the casein digests. Within the same substrate, the evolution of the peptide pattern at different time points showed minimal changes, suggesting that the protein degradation rate relies more on the gastrointestinal location than on digestion time. Higher plasma concentrations of methionine, valine, lysine and amino acid metabolites were found in animals fed with the hydrolysate at short times (<200 min). The duodenal peptide profiles were evaluated with discriminant analysis tools specific for peptidomics to identify sequence differences between both substrates that can be used for future human physiological and metabolic studies.
已知与完整的酪蛋白相比，酪蛋白水解会加速胃肠道的转运，尽管蛋白质水解对消化物组成的影响尚未完全了解。本工作的目的是在肽组学水平上对猪的十二指肠消化物进行表征，作为人类消化的模型，用胶束酪蛋白和先前描述的酪蛋白水解物进行喂养。此外，在平行实验中，还定量了血浆氨基酸水平。当动物接受胶束酪蛋白时，发现氮向十二指肠的转运速度较慢。与水解物相比，来自酪蛋白的十二指肠消化物中肽的大小范围更广，并且含有更多长度超过五个氨基酸的肽。肽谱明显不同，尽管在水解物样品中也发现了β-酪啡肽-7 前体，但在酪蛋白消化物中，其他阿片样序列更为丰富。在相同的底物中，不同时间点的肽模式的演变变化最小，这表明蛋白质降解率更多地依赖于胃肠道位置而不是消化时间。在短时间（<200 分钟）内用水解物喂养的动物中，发现蛋氨酸、缬氨酸、赖氨酸和氨基酸代谢物的血浆浓度更高。使用专门用于肽组学的判别分析工具评估十二指肠肽谱，以识别两种底物之间的序列差异，这些差异可用于未来的人类生理和代谢研究。
