The Cycling Endurance Study

Probiotic supplementation increases carbohydrate metabolism in trained male cyclists: a randomised, double-blind, placebo-controlled cross-over trial

SUMMARY

The aim of this double-blind placebo-controlled crossover study was to investigate whether probiotic supplementation increases the oxidation of an ingested maltodextrin drink and total carbohydrate oxidation during 2 hours of cycling exercise at 55% maximal aerobic power output.
The cyclists taking Lab4 probiotics for 4 weeks were able to oxidise more of orally-ingested carbohydrates during cycling endurance exercise.
Lab4 probiotics supplementation led to a reduction in fat oxidation.

Aim

This randomised, double-blind, placebo-controlled endurance study aimed to assess whether Lab4 probiotic supplementation increases the absorption and oxidation of orally-ingested maltodextrin and total carbohydrates oxidation during 2 hours’ endurance cycling.

Method

Results

Carbohydrate oxidation

Significant increase in carbohydrate (CHO) oxidation in the Lab4 probiotic group compared to placebo (*P<0.05).

Fat oxidation

Significant reduction in fat oxidation in the Lab4 probiotic group compared to placebo (*P<0.05).

Plasma Glucose

Significant increase in total plasma glucose levels in the Lab4 probiotic group compared to placebo (AUC, #P=0.013).

Significant increase in the plasma glucose levels originated from orally-ingested maltodextrin drink at 15 min of exercise in the Lab4 probiotic group compared to placebo (*P=0.01).

Plasma Insulin

Significant increase in plasma insulin levels at 30, 45 and 75 min in the Lab4 probiotic group compared to placebo (*P<0.05).

Significant increase in total insulin concentration in the Lab4 probiotic group compared to placebo (AUC, #P=0.04).

Gut symptoms

The incidence of gastrointestinal symptoms during cycling exercise was low in both groups, suggesting that the intensity and duration of the exercise did not lead to significant gut disturbance.

Conclusion

Lab4 probiotics supplementation increases total carbohydrate oxidation, whereas fat oxidation was reduced during the endurance cycling.

Reference

Pugh JN et al 2020. Probiotic supplementation increases carbohydrate metabolism in trained male cyclists: a randomised, double-blind, placebo-controlled crossover trial. American Journal of Physiology, Endocrinology and Metabolism 318 (4): E504-E513