Effect of supplementation with Saccharomyces boulardii on academic examination performance and related stress in healthy medical students

The dataset underlies the results reported in the paper entitled "Effect of Supplementation with Saccharomyces Boulardii on Academic Examination Performance and Related Stress in Healthy Medical Students: A Randomized, Double-Blind, Placebo-Controlled Trial" by Karbownik MS et al. published in "Nutrients" 2020; 12. Data presented in grey was imputed using Multiple Imputation by Chained Equations. Abstract In recent years, bacterial probiotic dietary supplementation has emerged as a promising way to improve cognition and to alleviate stress and anxiety; however, yeast probiotics have not been tested. The aim of the present study was to determine whether 30-day supplementation with Saccharomyces boulardii enhances academic performance under stress and affects stress markers. The trial was retrospectively registered at clinicaltrials.gov (NCT03427515). Healthy medical students were randomized to supplement their diet with Saccharomyces boulardii CNCM I-1079 or placebo before sitting for an academic examination, which served as a model of stress. The grades of a final examination adjusted to subject knowledge tested in non-stressful conditions were used as a primary outcome measure. Psychometrically evaluated state anxiety, cortisol and metanephrine salivary levels, and pulse rate were tested at a non-stressful time point before the intervention as well as just before the stressor. Fifty enrolled participants (22.6 ± 1.4 years of age, 19 males) completed the trial in the Saccharomyces and placebo arms. Supplementation with Saccharomyces did not significantly modify examination performance or increase in state anxiety, salivary cortisol, and metanephrine. However, the intervention resulted in higher increase in pulse rate under stress as compared to placebo by 10.4 (95% CI 4.2–16.6) min−1 (p = 0.0018), and the effect positively correlated with increase in salivary metanephrine (Pearson’s r = 0.35, 95% CI 0.09–0.58, p = 0.012). An intention-to-treat analysis was in line with the per-protocol one. In conclusion, supplementation with Saccharomyces boulardii CNCM I-1079 appears largely ineffective in improving academic performance under stress and in alleviating some stress markers, but it seems to increase pulse rate under stress, which may hypothetically reflect enhanced sympathoadrenal activity.

本数据集支撑了Karbownik MS等人于2020年发表于《Nutrients》期刊第12卷的论文《布拉氏酵母菌（Saccharomyces boulardii）补充对健康医学生考试表现及相关应激的影响：一项随机双盲安慰剂对照试验》中所报告的研究结果。灰色区域呈现的数据采用链式多重插补法（Multiple Imputation by Chained Equations）进行了补全。

摘要：近年来，细菌性益生菌膳食补充剂已成为改善认知、缓解应激与焦虑的潜在有效手段，但酵母菌类益生菌尚未得到相关研究验证。本研究旨在探究为期30天的布拉氏酵母菌补充是否能提升应激状态下的学业表现，并对应激标志物产生影响。本试验已于clinicaltrials.gov平台回溯注册（注册号NCT03427515）。

研究将健康医学生随机分组，在参加作为应激模型的学业考试前，分别通过膳食补充布拉氏酵母菌CNCM I-1079或安慰剂。以经非应激环境下科目知识测试结果校正后的期末考试成绩作为主要结局指标。分别于干预前的非应激时间点，以及应激刺激施加前，对经心理测量评估的状态焦虑、唾液皮质醇与变肾上腺素水平，以及脉搏率进行了检测。

共计50名入组受试者（年龄22.6±1.4岁，男性19名）完成了布拉氏酵母菌组与安慰剂组的全部试验流程。

布拉氏酵母菌补充干预未显著改变受试者的考试表现，也未加剧状态焦虑、唾液皮质醇与变肾上腺素水平的升高。然而，与安慰剂组相比，干预组受试者在应激状态下的脉搏率升高幅度高出10.4次/分钟（95%置信区间：4.2–16.6 min⁻¹，p=0.0018），且该脉搏率升高幅度与唾液变肾上腺素水平的升高呈正相关（Pearson相关系数r=0.35，95%置信区间：0.09–0.58，p=0.012）。意向性治疗分析结果与符合方案分析结果一致。

综上，补充布拉氏酵母菌CNCM I-1079在提升应激状态下的学业表现、缓解部分应激标志物方面整体效果不佳，但似乎会加剧应激状态下的脉搏率升高，该现象可推测反映了交感肾上腺活动的增强。