Recent study results out of Austria suggest that a multi-species probiotic blend may help support immune health in trained athletes by reducing the incidence of upper respiratory tract infections (URTIs) and beneficially modulating tryptophan-kynurenine metabolism. While past studies have found that exhaustive aerobic exercise in athletes may significantly impact tryptophan-kynurenine metabolism—which can influence immunosurveillance and the development of infections—these more recent findings suggest this probiotic blend may reduce such potentially detrimental degradation rates in tryptophan.
The double-blind, placebo-controlled study included 33 healthy, highly trained athletes with a mean age of 26.7 years. For 12 weeks, participants were randomized to receive either a placebo or a probiotic supplement daily containing 1 × 1010 colony forming units (CFUs) of the multi-species probiotic Ecologic Performance from Winclove Probiotics (Amsterdam, The Netherlands), which combines Bifidobacterium bifidum W23, Bifidobacterium lactis W51, Enterococcus faecium W54, Lactobacillus acidophilus W22, Lactobacillus brevis W63, and Lactococcus lactis W58.
At both baseline and after 12 weeks of supplementation, researchers measured participant serum concentrations of tryptophan, phenylalanine, kynurenine, and tyrosine, with concentrations measured at rest and immediately following exercise, consisting of an incremental cycle ergometer exercise test. Additionally, subjects completed a daily diary to identify symptoms of URTIs.
After 12 weeks of treatment, researchers found that post-exercise tryptophan levels were lowered by a significant 11% in the placebo group compared to baseline, but the probiotic group's post-exercise tryptophan levels remained unchanged. What's more, subjects in the placebo group who reported experiencing one or more URTI symptoms was increased 2.2-fold compared to the probiotic group.
“Data indicate reduced exercise-induced tryptophan degradation rates in the [probiotic] group,” researchers concluded. “Daily supplementation with probiotic limited exercise-induced drops in tryptophan levels and reduce the incidence of URTI, however, [it] did not benefit athletic performance.”
Strasser B et al., “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,” Nutrients, vol. 8, no. 11 (November, 2016): 752