The influence of a dietary supplement (NDS Baseline Probiotic) on the gastrointestinal quality and physical performance of endurance runners

Introduction: <br>Endurance runners suffer from gastrointestinal (GI) symptoms which can disrupt training or even prevent participation in competitions. Especially long-distance running affects the integrity of the intestinal mucosa. Dietary behaviour during training and competition is a significant factor in the prevention of such exercise-induced GI problems. The efficacy of probiotics in the treatment of GI diseases is well established. A long list of health and developmental benefits were attributed to probiotics in regard to GI symptoms and a disturbed integrity of the intestinal mucosa. The aim of the present study was to investigate the influence of a dietary supplement (NDS baseline probiotic®) on the gastrointestinal quality and physical performance of endurance runners. <br> <br>Methods: <br>The study was conducted in a prospective, randomised controlled and double-blind cross-over design. The overall observation period lasted 12 weeks, three periods of 4 weeks each: First intervention period (I1), wash-out period (WOP) and second intervention period (I2). In total there were four examinations, three by a medical doctor - before (U1) and after (U2) I1 and after I2 (U4) - and an additional examination (U3) after wash-out period, where the subjects only handed in the questionnaires and the training protocol. The study population comprised professional and competitive amateur-runners (> 4 hours running per week; participation in > 1 running competition per year) suffering from exercise-induced GI symptoms (Gastrointestinal Quality of Life Index according to Eypasch (GIQLI) <=112 points). 62 athletes were included in the intent-to-treat population and randomised to verum-placebo and placebo-verum group. NDS baseline probiotic® contains 109 viable bacteria of six strains per gram and the placebo was free of bacteria. Both are a white powder, packed in 5g sachets and recommended to be consumed dissolved in a glass of water, one sachet per day. All athletes had to fill out two questionnaires four times (U1, U2, U3 and U2), the GIQLI and the athletic and demographic profile questionnaire. The subjects kept a training protocol and noted exercise-induced occurrences of diarrhoea during the whole observation period. A Hemoccult®-test was conducted three times (U1, U2 and U2) to detect possible serious occult bleeding. From the 62 athletes, 26 regional athletes living close to the investigation centre were assigned to a so-called subgroup. They participated in “extra-examinations” (after I1: U2+; after I2: U4+) including exercise stress tests to determine systemic and ex-vivo stimulated release of cytokines (IL-6, TNF-a and IL-10 in EDTA-plasma, in unstimulated and LPS-stimulated whole blood cultures), and to determine systemic release of acute-phase proteins (C3c, C4 and hsCRP in EDTA-plasma) and immunoglobulins (IgG, IgA and IgM in EDTA-plasma) and to measure gut permeability (urinary lactulose and rhamnose excretion; dosage: 5g lactulose and 0,5g rhamnose) before and after exercise stress tests (field test: 60 min running at 80% VO2max). <br> <br>Results: <br>The GIQLI improved over the whole observation period for all subjects, however cross-over analysis showed a treatment effect in favour of the placebo. Exercise-induced occurrences of diarrhoea decreased over the whole observation period, but no treatment effects were observed after cross-over analysis. No serious occult bleeding was found using the Hemoccult®-test, therefore cross-over analysis showed no treatment effects. Cytokines in EDTA-plasma significantly increased after exercise-stress test. Concerning immunoglobulins, there was a significant increase in IgG concentration in EDTA-plasma after exercise, but IgM and IgA concentration did not show significant differences. Exercise stress tests did not significantly influence acute-phase protein (C3c, C4 and hsCRP) concentration in EDTA-plasma. Concerning unstimulated whole blood cultures only IL-10 showed a significant difference in the placebo group after exercise. Concerning LPS-stimulated whole blood cultures a significant difference after exercise was only found in IL-10 after exercise. Cross-over analysis of the immunological parameters in the blood (before and after exercise) did not show any significant treatment effects. Small intestinal permeability (lactulose/rhamnose ratio) was increased after the exercise stress tests. Cross-over-analysis showed an interaction effect. Therefore only data of I1 were included for analysis. Then a treatment effect was found in favour of the probiotic supplement. <br> <br>Conclusion: <br>The dietary supplement NDS baseline probiotic® showed no beneficial effect on the gastrointestinal quality (GIQLI) and physical performance of endurance runners and on the exercise-induced occurrences of diarrhoea, and the outcome of Hemoccult®-tests. Nevertheless, a positive effect on exercise-induced changes in IL-10 concentration in LPS stimulated whole blood and the exercise-induced increase of the gut permeability test was shown. This could be a possible indication for beneficial influence of probiotics on exercise-induced GI symptoms of endurance runners.

Author dc:creator

• Lutz, Annette Katharina

Contributors dc:contributor

• Gollhofer, Albert

• Gastrointestinal symptoms endurance runners probiotic supplemen
• physical performance

Repository record source_url

https://freidok.uni-freiburg.de/data/2220

OAI identifier oai:identifier

oai:freidok.uni-freiburg.de:2220