The effect of probiotics on respiratory infections and gastrointestinal symptoms during training in marathon runners.
ABSTRACT Heavy exercise is associated with an increased risk of upper respiratory tract infections. Strenuous exercise also causes gastrointestinal (GI) symptoms. In previous studies probiotics have reduced respiratory tract infections and GI symptoms in general populations including children, adults, and the elderly. These questions have not been studied in athletes before. The purpose of this study was to investigate the effect of probiotics on the number of healthy days, respiratory infections, and GI-symptom episodes in marathon runners in the summer. Marathon runners (N = 141) were recruited for a randomized, double-blind intervention study during which they received Lactobacillus rhamnosus GG (LGG) or placebo for a 3-mo training period. At the end of the training period the subjects took part in a marathon race, after which they were followed up for 2 wk. The mean number of healthy days was 79.0 in the LGG group and 73.4 in the placebo group (P = 0.82). There were no differences in the number of respiratory infections or GI-symptom episodes. The duration of GI-symptom episodes in the LGG group was 2.9 vs. 4.3 d in the placebo group during the training period (P = 0.35) and 1.0 vs. 2.3 d, respectively, during the 2 wk after the marathon (P = 0.046). LGG had no effect on the incidence of respiratory infections or GI-symptom episodes in marathon runners, but it seemed to shorten the duration of GI-symptom episodes.
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ABSTRACT: Abstract Probiotic supplementation has traditionally focused on gut health. However, in recent years, the clinical applications of probiotics have broadened to allergic, metabolic, inflammatory, gastrointestinal and respiratory conditions. Gastrointestinal health is important for regulating adaptation to exercise and physical activity. Symptoms such as nausea, bloating, cramping, pain, diarrhoea and bleeding occur in some athletes, particularly during prolonged exhaustive events. Several studies conducted since 2006 examining probiotic supplementation in athletes or highly active individuals indicate modest clinical benefits in terms of reduced frequency, severity and/or duration of respiratory and gastrointestinal illness. The likely mechanisms of action for probiotics include direct interaction with the gut microbiota, interaction with the mucosal immune system and immune signalling to a variety of organs and systems. Practical issues to consider include medical and dietary screening of athletes, sourcing of recommended probiotics and formulations, dose-response requirements for different probiotic strains, storage, handling and transport of supplements and timing of supplementation in relation to travel and competition.European Journal of Sport Science 10/2014; 15(1):1-10. DOI:10.1080/17461391.2014.971879 · 1.31 Impact Factor
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ABSTRACT: Viral respiratory infections are the most common diseases in humans. A large range of etiologic agents challenge the development of efficient therapies. Research suggests that probiotics are able to decrease the risk or duration of respiratory infection symptoms. However, the antiviral mechanisms of probiotics are unclear. The purpose of this paper is to review the current knowledge on the effects of probiotics on respiratory virus infections and to provide insights on the possible antiviral mechanisms of probiotics. A PubMed and Scopus database search was performed up to January 2014 using appropriate search terms on probiotic and respiratory virus infections in cell models, in animal models, and in humans, and reviewed for their relevance. Altogether, thirty-three clinical trials were reviewed. The studies varied highly in study design, outcome measures, probiotics, dose, and matrices used. Twenty-eight trials reported that probiotics had beneficial effects in the outcome of respiratory tract infections (RTIs) and five showed no clear benefit. Only eight studies reported investigating viral etiology from the respiratory tract, and one of these reported a significant decrease in viral load. Based on experimental studies, probiotics may exert antiviral effects directly in probiotic-virus interaction or via stimulation of the immune system. Although probiotics seem to be beneficial in respiratory illnesses, the role of probiotics on specific viruses has not been investigated sufficiently. Due to the lack of confirmatory studies and varied data available, more randomized, double-blind, and placebo-controlled trials in different age populations investigating probiotic dose response, comparing probiotic strains/genera, and elucidating the antiviral effect mechanisms are necessary.European Journal of Clinical Microbiology 03/2014; DOI:10.1007/s10096-014-2086-y · 2.54 Impact Factor
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ABSTRACT: To determine the effects of probiotic yogurt on performance and health status of young adultfemale endurance swimmers. In a randomized controlled trial, 46 endurance swimmers girls with mean age of 13.8 ±1.8 years,weight of 48.6±7.5kg and height of 159±5.6cm, were studied. Subjects were randomly assigned into two groups,receiving either 400 ml probiotic yogurt (intervention group) or ordinary yogurt (control group) daily for 8weeks. At the beginning and at the end of the study, the 400-m free swimming record was done and the HarvardStep test was employed to measure VO2max. Statistical analysis of the data was performed using SPSS software.This trial has been registered with IRCT ID of IRCT2012122311849N1. Average changes in the records of the intervention and control groups were 3.9 and 0.5 seconds, respectively(p= 0.22). The intervention group complained of dyspnea for 2.4 days and the value for the controlwas 4.4 days (p=0.024). Values for ear pain were 0.5 and 1.6 days (p=0.008) respectively. The average numberof episodes of respiratory infection in the intervention group was 0.9 day, which was statistically fewer than thatin the control group (1.4 days), P=0.009. A reduction in the number of episodes of respiratory infections and duration of some symptomssuch as dyspnea and ear pain was observed. Due to the reduction in upper respiratory tract infections of theathletes following intake of probiotic yogurt, improvement in VO2max is possible.Medical journal of the Islamic Republic of Iran 08/2013; 27(3):141-146.