The impact of test anxiety on oral microbiota among medical students-A pilot study.

Test anxiety (TA) is a common emotion among students during examinations. Test-induced stress can remarkably impact students' emotions and limit their performance. Mental stress is a crucial factor that could significantly alter gut microbial composition, but rare reports focus on the correlation between TA and oral microbial composition. This study aims to investigate the impact of TA on students' oral microbiota composition. This study targeted medical students who usually face heavier workloads than average undergraduates. 28 females and 19 males aged 18-30 were enrolled in this study. Questionnaires and saliva samples were collected from the participants before, during, and after the end-term examination. The level of anxiety was classified as normal, mild, moderate, and severe based on the questionnaire scores. In addition, 16S amplicon sequencing was used to analyse the composition of oral microbes. More than half of the students faced different levels of TA before and after the examination. Over three-quarters of students showed anxiety during the examination, and a quarter suffered severe TA. The 16S sequencing data showed that TA significantly altered the oral microbial composition between students with and without TA in all three survey periods. Moreover, during the examination, the genera Rothia and Streptococcus, the oral-beneficial bacteria, markedly decreased in students with TA. On the other hand, the potential pathogenic genera, such as Prevotella, Fusobacterium, and Haemophilus, significantly increased in the students with TA. And the TA effect on oral microbes displayed a gender difference among students. A high ratio of TA existed in the students during their examination period, and TA could significantly alter the oral microbial composition, decrease beneficial microbes, and promote potential pathogenic oral microbes.

Probiotic Supplement Preparation Relieves Test Anxiety by Regulating Intestinal Microbiota in College Students.

Test anxiety creates barriers to learning and performance, which further affects students' social, behavioural, and emotional development. Currently, the medication to treat test anxiety has not been reported yet. Here, we enrolled 120 students to evaluate the effect of probiotic supplement preparation (PSP) on test anxiety from the aspect of the intestinal microbiota. We found that the intake of PSP alleviated the symptoms of depression and anxiety in students with test anxiety by evaluating their mental state using the Hamilton Depression Rating Scale and Hamilton Anxiety Scale. High-throughput sequencing results indicated that the consumption of PSP increased the abundance of Streptococcus and Akkermansia that was lowered by the anxiety state in the intestinal microbiota of students. Meanwhile, taking PSP reduced the level of intestinal pathogens of Fusobacterium and Clostridium as well. In conclusion, our work shows that PSP can reduce test anxiety and restore the disturbed microbiota to the standard level in Chinese college students, rendering the use of PSP a promising strategy for test anxiety.

Effect of Supplementation with Saccharomyces Boulardii on Academic Examination Performance and Related Stress in Healthy Medical Students: A Randomized, Double-Blind, Placebo-Controlled Trial.

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 was 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.