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Cited by 142Probiotics and Fermented FoodsExercise and Physiological ResponsesTryptophan and brain disorders

Probiotic Supplements Beneficially Affect Tryptophan–Kynurenine Metabolism and Reduce the Incidence of Upper Respiratory Tract Infections in Trained Athletes: A Randomized, Double-Blinded, Placebo-Controlled Trial

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Strasser, Barbara, Geiger, Daniela, Schauer, Markus, Gostner, Johanna, Gatterer, Hannes, Burtscher, Martin, Fuchs, Dietmar·2016·Nutrients
DOI 10.3390/nu8110752PMC PMC5133134
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Abstract

Background: Prolonged intense exercise has been associated with transient suppression of immune function and an increased risk of infections. In this context, the catabolism of amino acid tryptophan via kynurenine may play an important role. The present study examined the effect of a probiotic supplement on the incidence of upper respiratory tract infections (URTI) and the metabolism of aromatic amino acids after exhaustive aerobic exercise in trained athletes during three months of winter training. Methods: Thirty-three highly trained individuals were randomly assigned to probiotic (PRO, n = 17) or placebo (PLA, n = 16) groups using double blind procedures, receiving either 1 × 1010 colony forming units (CFU) of a multi-species probiotic (Bifidobacterium bifidum W23, Bifidobacterium lactis W51, Enterococcus faecium W54, Lactobacillus acidophilus W22, Lactobacillus brevis W63, and Lactococcus lactis W58) or placebo once per day for 12 weeks. The serum concentrations of tryptophan, phenylalanine and their primary catabolites kynurenine and tyrosine, as well as the concentration of the immune activation marker neopterin were determined at baseline and after 12 weeks, both at rest and immediately after exercise. Participants completed a daily diary to identify any infectious symptoms. Results: After 12 weeks of treatment, post-exercise tryptophan levels were lowered by 11% (a significant change) in the PLA group compared to the concentrations measured before the intervention (p = 0.02), but remained unchanged in the PRO group. The ratio of subjects taking the placebo who experienced one or more URTI symptoms was increased 2.2-fold compared to those on probiotics (PLA 0.79, PRO 0.35; p = 0.02). Conclusion: Data indicate reduced exercise-induced tryptophan degradation rates in the PRO group. Daily supplementation with probiotics limited exercise-induced drops in tryptophan levels and reduced the incidence of URTI, however, did not benefit athletic performance.

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  • In 33 trained athletes, 12 weeks of winter training supplementation with a multi-species probiotic did not benefit athletic performance, but training load was higher in those who supplemented with the probiotic blend vs. the placebo group.

    “In thirty-three trained athletes, 12 weeks of winter training supplementation with a multi-species probiotic did not benefit athletic performance; however, the training load (hours per week) was higher in those who supplemented with the probiotic blend vs. the placebo group [78].”

    From International Society of Sports Nutrition Position Stand: Probiotics (2019) · cites this paper as [78]

  • In highly trained athletes, 12 weeks of a multi-strain probiotic reduced the incidence of URTI compared to placebo and limited exercise-induced reductions in tryptophan levels.

    “Daily supplementation with probiotics reduced the incidence of URTI compared to placebo. In addition, supplementation limited exercise-induced reductions in tryptophan levels, which may reduce the risk of developing an infection.”

    From International Society of Sports Nutrition Position Stand: Probiotics (2019) · cites this paper as [78]

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Authors
Strasser, B., Geiger, D., Schauer, M., Gostner, J., Gatterer, H., Burtscher, M., & Fuchs, D.
Affiliations
  • Innsbruck Medical University (AT)
  • Universität Innsbruck (AT)
Corresponding author
Strasser, Barbara
ORCID
Venue
Nutrients
Publisher
MDPI AG
Published
2016-11-23
Volume
8
Issue
11
Pages
752
ISSN
2072-6643 (ISSN-L)
DOI
10.3390/nu8110752
PMC
PMC5133134
OpenAlex
W2552273282
Cited by
142
References
54
Citations by year
2026: 5 · 2025: 14 · 2024: 15 · 2023: 16 · 2022: 29 · 2021: 24 · 2020: 16 · 2019: 11 · 2018: 9 · 2017: 2 · 2015: 1
FWCI
9.23
Type
journal article
Language
en
Open access
Licence
Locations
  • Nutrients (publishedVersion, cc-by)
  • Europe PMC (PubMed Central) (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
Topics
  • Life Sciences › Agricultural and Biological Sciences › Food Science › Probiotics and Fermented Foods
  • Health Sciences › Medicine › Rehabilitation › Exercise and Physiological Responses
  • Life Sciences › Neuroscience › Biological Psychiatry › Tryptophan and brain disorders
Keywords
probiotics, tryptophan metabolism, kynurenine pathway, upper respiratory tract infection, trained athletes, immune function, neopterin, phenylalanine, tyrosine, Bifidobacterium, Lactobacillus, Enterococcus faecium, winter training, athletic performance
MeSH terms
Gastrointestinal Microbiome, Adult, Austria, Double-Blind Method, Female, Health Status, Humans, Kynurenine, Male, Phenylalanine, Physical Endurance, Physical Fitness, Respiratory Tract Infections, Risk Factors, Seasons, Time Factors, Tryptophan, Tyrosine, Biomarkers, Neopterin, Probiotics, Young Adult, Athletes, Physical Conditioning, Human

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