Probiotics are live microorganisms conferring health benefits when administered in adequate amounts. However, the passage through the gastrointestinal tract represents a challenge due to pH variations, proteases, and bile salts. This study aimed to evaluate the proteomic response of Saccharomyces boulardii to simulated gastrointestinal digestion and the influence of encapsulation on yeast viability. Different pH values and time periods simulating the passage through different sections of the gastrointestinal tract were applied to unencapsulated and encapsulated yeasts. Encapsulation in 0.5% calcium alginate did not improve yeast survival or induce changes in protein patterns whereas protein extracts from control and digested yeasts showed remarkable differences when separated by SDS-PAGE. Protein bands were analyzed by tandem mass spectrometry. Protein identification revealed unique proteins that changed acutely in abundance after simulated digestion. Carbohydrate metabolism, protein processing, and oxide-reduction were the biological processes most affected by simulated gastrointestinal digestion in S. boulardii.

中文翻译：

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布拉酵母菌对模拟胃肠道条件和封装的蛋白质组学反应。

益生菌是活的微生物，适量服用可带来健康益处。然而，由于 pH 值变化、蛋白酶和胆盐，通过胃肠道是一个挑战。本研究旨在评估布拉酵母菌对模拟胃肠道消化的蛋白质组学反应以及封装对酵母活力的影响。模拟通过胃肠道不同部分的不同pH值和时间段被应用于未封装和封装的酵母。0.5% 海藻酸钙封装不会提高酵母存活率或诱导蛋白质模式的变化，而对照和消化酵母的蛋白质提取物在通过 SDS-PAGE 分离时显示出显着差异。通过串联质谱法分析蛋白质条带。蛋白质鉴定揭示了模拟消化后丰度发生急剧变化的独特蛋白质。碳水化合物代谢、蛋白质加工和氧化物还原是布拉氏酵母中受模拟胃肠道消化影响最大的生物过程。