The Effect of Probiotics on GI Symptoms
Condition: Gastrointestinal Symptoms
Study type: Interventional

Summary: 
      A double-blind randomized, placebo-controlled study will be performed with experienced
      endurance athletes to assess the effect of probiotics supplementation on the occurrence and
      intensity of the gastrointestinal symptoms, on performance and on the composition and
      function of the gut microbiota. The duration of the supplementation period, with Ecologic®
      PERFORMANCE supplements, is fourteen weeks. Standardized maximum exercise tests on a
      treadmill are performed before and after the supplementation period, as well as two
      performance tests (before) and one performance test (after). During the performance tests,
      the load is first submaximal for 1 hour, after which a time trial of 30 minutes will be
      performed. The measurements before and after the supplementation period are performed on
      individual days with at least 48 hours of relative rest in between. During the
      supplementation period, training diaries, a Profile of Mood States (POMS) questionnaire and a
      few questionnaires about dietary habits will be completed.
    

Detailed description: 
      Rationale: Endurance exercise, such as running a marathon, is becoming increasingly popular.
      In addition to the many positive health effects of endurance exercise, it can also be
      accompanied by gastrointestinal symptoms. For example, around 30-90% of runners suffer from
      gastrointestinal symptoms during or in the hours after intensive/endurance running. The
      occurrence of gastrointestinal symptoms is probably due to the redistribution of blood
      volume, resulting in less blood supply to the digestive tract and a less functioning
      intestinal barrier. Because the intestinal barrier functions less, endotoxins can enter the
      bloodstream and cause inflammatory reactions. Running in the heat causes extra redistribution
      of the blood volume, because extra blood is needed for cooling of the body. It is known that
      the gut microbiota affect food digestion, but also the functioning of the cells that line the
      intestinal wall and the connections between these cells. It is possible that runners with
      gastrointestinal symptoms face a different composition of the gut microbiota and / or
      metabolites during endurance exercise compared to runners without any complaints, as a result
      of which the gut barrier functions less well and problems may occur. Many positive effects
      have been attributed to the use of probiotics in general. Amongst which, the reduction of
      gastrointestinal symptoms during endurance exercise, probably due to improvement in
      intestinal permeability. Hence, the main goal of our research project is to investigate
      whether the chance of and/or intensity of gastrointestinal symptoms during endurance exercise
      and the exercise performance can be influenced by probiotics supplementation in trained
      endurance athletes. This will be studied in relation to the composition of the gut microbiota
      and / or metabolites.

      Objective:

      Primary Objective:

      Can the chance at and/or intensity of gastrointestinal symptoms during exercise be influenced
      by probiotics supplementation in trained endurance athletes who experience these symptoms and
      can performance be enhanced? Secondairy Objective: Can the composition and function of the
      gut microbiota of trained athletes that experience gastrointestinal symptoms during exercise
      be positively influenced by probiotics supplementation?

      Study design: A double-blind randomized placebo-controlled trial will be performed to
      investigate the effect of 14 weeks probiotics supplementation with Ecologic® PERFORMANCE
      supplements. Standardized maximal incremental exercise tests will be performed before and
      after the supplementation period, as well as two performance tests (before) and one
      performance test (after). During the supplementation period training diaries, a POMS
      questionnaire and some questionnaires about food habits will be completed, a food diary and
      Food Frequency Questionnaire (FFQ).

      Study population: Healthy male endurance athletes of Dutch nationality, 18-45 years old, who
      regularly experience gastrointestinal symptoms during exercise.

      Intervention: Fourteen weeks of supplementation with Ecologic® PERFORMANCE probiotics
      supplements (or placebo).

      Main study parameters/endpoints: Main study endpoints are differences in changes in the
      severity and occurrence of gastrointestinal symptoms and changes in exercise performance
      (total distance on a time trial and maximum speed during an incremental exercise test). Also
      changes in composition of the microbiota and differences in changes in the metabolites in the
      stool sample before and after the supplementation period in the experimental and control
      group will be studied.

      Nature and extent of the burden and risks associated with participation, benefit and group
      relatedness: Benefits will be the value of the test results and outcome measures of the
      microbiome analysis. Also the chance on a reduced risk of occurrence of gastrointestinal
      symptoms might be of value for potential participants. The risks for the participants are
      minor. Only participants that are healthy and endurance trained will be included. In the
      Human Performance Laboratory of the Faculty of Behavioural and Human Movement Sciences,
      performance tests in warm conditions are executed regularly and health risks related to the
      experimental protocol are minor for the participants since they are already well-trained and
      the exercise intensity will be relatively well-tolerated, since they are used to similar
      efforts. Probiotics supplements are freely available at the market, and the Ecologic®
      PERFORMANCE supplements are available in the web shop of Winclove B.V. The same supplement
      has been used before in the same dosage and no adverse effects were reported. Participants
      will fill in a food frequency questionnaire and questionnaire about gastrointestinal symptoms
      and hand in a stool sample before and after the supplementation period. They will be asked to
      maintain a training diary during the supplementation period and also fill in the POMS
      questionnaire weekly. The maximal incremental exercise test (2 times) consists of a
      warming-up followed by incremental increase in running velocity until voluntary exhaustion.
      The performance tests (3 times) consists of 60 minutes of submaximal running followed by a
      time trial of 30 minutes in which participants need to accomplish as much distance as
      possible.
    

Intervention name(s): Ecologic® PERFORMANCE; Placebo
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): Ecologic® PERFORMANCE is a probiotic formulation consisting of different probiotic bacterial strains, namely:
Bifidobacterium bifidum W23 Bifidobacterium lactis W51 Enterococcus faecium W54 Lactobacillus acidophilus W22 Lactobacillus brevis W63 Lactococcus lactis W58
Except for the bacterial strains, Ecologic® PERFORMANCE contains the following other ingredients:
maize starch and maltodextrins
fructo-oligosaccharides (FOS) P6 and Polydextrose P4 (strain specific prebiotics)
vegetable protein
mineral mix (Potassium chloride, Magnesium sulphate, Manganese sulphate); The placebo contains no bacterial strains, but the following ingredients:
maize starch and maltodextrins
fructo-oligosaccharides (FOS) P6 and Polydextrose P4 (strain specific prebiotics)
vegetable protein
mineral mix (Potassium chloride, Magnesium sulphate, Manganese sulphate)
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Randomized controlled trial
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: Endurance athletes; probiotics; endurance exercise