Table_2_Health Benefits of Probiotics in Sport and Exercise - Non-existent or a Matter of Heterogeneity? A Systematic Review.pdf

BackgroundThe use of probiotics in sports has been growing in recent years, as up to 50% of athletes suffer from training- and performance-limiting gastrointestinal (GI) problems. Moreover, repeated exhaustive exercise and high training loads may lead to a transiently depressed immune function, associated with an increased risk of upper respiratory tract infection (URTI).AimTo provide a qualitative analysis of probiotic effects on URTI, GI symptoms and the immune system in healthy individuals under consideration of performance level as main classifier.MethodsA systematic review of the literature was conducted (PubMed, SPORTDiscus with Full Text, Web of Science) to analyze the effects of probiotics in athletes and healthy active individuals on GI problems, URTI, and the immune system. A qualitative synthesis with performance level and treatment duration as main classifiers was performed.ResultsOf 41 eligible studies, 24 evaluated the effects of probiotic supplements in athletes, 10 in recreationally active individuals and 7 in healthy untrained adults. Large heterogeneity was observed in terms of probiotic strains, mode of delivery, performance level, treatment duration and outcome assessment. Overall, studies provided inconsistent observations.ConclusionThe effects of probiotics on immune system, URTI, and GI symptoms in athletes, healthy adults and recreationally active individuals remain inconclusive. Based on the analyzed studies and identified parameters, this article provides suggestions to align future research on the effects of probiotics in exercise.Systematic Review RegistrationPROSPERO, identifier: CRD42021245840.

背景：近年来，益生菌在体育领域的应用日益广泛，因为高达50%的运动员遭受着训练和表现受限的胃肠道（GI）问题。此外，反复的极度运动和高强度的训练负荷可能导致暂时性免疫功能的下降，这与上呼吸道感染（URTI）风险的增加有关。目的：本研究旨在对益生菌对URTI、GI症状以及健康个体免疫系统的影响进行定性分析，并将表现水平作为主要分类标准。方法：通过系统文献综述（PubMed、SPORTDiscus with Full Text、Web of Science）分析了益生菌对运动员和健康活跃个体的胃肠道问题、URTI和免疫系统的影响。以表现水平和治疗持续时间作为主要分类标准，进行了定性综合分析。结果：在41项合格研究中，24项评估了益生菌补充剂对运动员的影响，10项评估了休闲活跃个体的影响，7项评估了健康未训练成年人的影响。在益生菌菌株、给药方式、表现水平、治疗持续时间以及结果评估方面，存在较大的异质性。总体而言，研究提供了不一致的观察结果。结论：益生菌对运动员、健康成年人和休闲活跃个体在免疫系统、URTI和GI症状上的影响尚无定论。基于所分析的文献和识别的参数，本文为未来关于益生菌在运动中作用的研究提供了建议。系统综述注册：PROSPERO，标识符：CRD42021245840。