Effects of probiotic supplementation on performance of resistance and aerobic exercises: a systematic review

Context Strenuous exercise may lead to negative acute physiological effects that can impair athletic performance. Some recent studies suggest that probiotic supplementation can curtail these effects by reducing the permeability of the intestinal barrier, yet results are inconsistent. Objective The aim of this systematic review is to assess the effects of probiotic supplementation on athletic performance. Data Sources The PubMed/MEDLINE, Cochrane, and Scopus databases were searched for articles that assessed the effects of probiotic supplementation on athletic performance. Data Extraction This systematic review is reported according to PRISMA guidelines. Risk of bias was assessed through the Cochrane RoB 2.0 tool. Seventeen randomized clinical trials assessing athletic performance as the primary outcome were included. In total, 496 individuals (73% male) comprising athletes, recreationally trained individuals, and untrained healthy individuals aged 18 to 40 years were investigated. Data Analysis Three studies showed an increase or an attenuation of aerobic performance (decline in time to exhaustion on the treadmill) after supplementation with probiotics, while 3 found an increase in strength. However, most studies (n = 11) showed no effect of probiotic consumption on aerobic performance (n = 9) or muscular strength (n = 2). The most frequently used strain was Lactobacillus acidophilus, used in 2 studies that observed positive results on performance. Studies that used Lactobacillus plantarum TK10 and Lactobacillus plantarum PS128 also demonstrated positive effects on aerobic performance and strength, but they had high risk of bias, which implies low confidence about the actual effect of treatment. Conclusion There is not enough evidence to support the hypothesis that probiotics can improve performance in resistance and aerobic exercises. Further well-controlled studies are warranted.