Skip to content
Information for healthcare professionals

Search Research

Contact Us

Gleeson (2008) The effect of 14 days supplementation with Yakult probiotic on circulating hormonal, leukocyte, and cytokine responses to prolonged cycling in man

Gleeson (2008) The effect of 14 days supplementation with Yakult probiotic on circulating hormonal, leukocyte, and cytokine responses to prolonged cycling in man

Citation

Gleeson M (2008) The effect of 14 days supplementation with Yakult probiotic on circulating hormonal, leukocyte, and cytokine responses to prolonged cycling in man. International Journal Probiotics & Prebiotics 3(3): 185 

Objective

To investigate the effects of a daily probiotic (Yakult) on immunendocrine responses to a bout of prolonged cycling.

Methods

This was a small double-blinded, placebo-controlled crossover pilot study involving five trained male adult cyclists, with a washout period of two weeks. The subjects consumed two bottles of probiotic (each containing a minimum of 6.5 x 109 CFU Lactobacillus casei Shirota) or placebo daily for a two week period, which was followed by a 2.5 h cycle ergonometer exercise trial at 60% of maximal oxygen uptake. Saliva (for IgA) and blood samples were taken before, immediately after, and one hour after this exercise period. Blood leukocytes and lymphocyte subsets, phorbol myrisate acetate-stimulated neutrophil oxidative burst activity and plasma hormone and cytokines were analysed. 

Results

Post-exercise blood neutrophil counts and plasma ACTH were higher in the probiotic group compared to the placebo group (both P + CD4+) and the CD4+/CD8+ ratio were higher in the probiotic group (main effect of the trial, P = 0.01). Saliva IgA concentrations tended to be higher in the probiotic group compared to the placebo (P = 0.06).

Total leukocytes, lymphocytes, cytotoxic T cells, NK cells and plasma hGH, IL-6 and IL-10 all increased post exercise to a similar extent for both groups. There was no significant difference between the two groups for their average exercise intensity, heart rate and rating of perceived exertion. 

Conclusions

The main effect of the probiotic was an increase in circulating CD4+ cells and CD4+/CD8+ ratio, regardless of exercise. Both these immune parameters can be reduced during intensive exercise and prolonged training. A large trial is needed to ascertain whether Yakult supplementation may boost mucosal IgA, which is suggested by the salivary Ig data.

 
 
Back to top