It has been described that adaptations to exercise might be influenced by the gut microbiota, although the specific role of the microbiota in improving energy metabolism and hydration status and modulating redox and immune responses during exercise is poorly studied in humans. According to recent data, exercise may induce modifications in the gut microbiota composition; little is known about whether modulation of the gut microbiota by probiotics may contribute to an individual’s exercise performance. Despite the fact that the role of probiotics in modulating the mucosal immune system has been previously described, data regarding the influence of probiotics on professional athletes’ immunity is scarce.
Following a randomized, double-blind and placebo-controlled design, researchers randomly allocated professional athletes (aged 18-28 years and with normal weight) to the probiotic (n=15) or the placebo (n=15) group. The experimental group received 2 capsules per day of a probiotic containing Lactobacillus helveticus Lafti® L10 for 14 weeks. Each capsule contained 1 x 1010 colony forming units (CFU) of L. helveticus Lafti® L10. Serum and saliva samples were collected at baseline and after 14 weeks. Total and specific anti-bacterial antibody levels of immunoglobulin M (IgM), IgG and IgA classes were determined towards different bacteria in serum, whereas in saliva total and specific anti-bacterial IgA levels were measured.
No significant differences were observed in total and specific IgM and total IgG levels between probiotic and placebo groups. The placebo group showed a significant reduction of anti-Enterococcus faecalis IgG (in serum) and total IgA levels (in both serum and saliva) when compared to the probiotic group. The preservation of total salivary IgA level in the probiotic group suggests that the probiotic affected the mucosal surface, the first line of defence against pathogens, and thus could be useful in preventing upper respiratory tract infections (URTI), which are highly prevalent in those performing strenuous exercise. The researchers emphasized that the mechanisms involved in immune changes observed systemically and locally in the probiotic group could be different, so mechanisms of the interactions between L. helveticus and immunity require further research to be elucidated.
All together, these results show that a probiotic with L. helveticus Lafti® L10 strain could have beneficial effects on both systemic humoral and mucosal immune responses in elite athletes.
Andreu Prados Andreu Prados holds a Bachelor of Science Degree in Pharmacy & Human Nutrition and Dietetics. Science writer specialised in gut microbiota and probiotics, working also as lecturer and consultant in nutrition and healthcare. Follow Andreu on Twitter @andreuprados