The probiotics were also associated with a decrease in the number of symptoms, reported the researchers in Applied Physiology, Nutrition, and Metabolism.
“We report a significant increase of CD4+/CD8+ (T helper/T suppressor) cells ratio in the probiotic group,” wrote researchers from the University of Belgrade and the Sports Medicine Association of Serbia. “Apparently, CD4+/CD8+ ratio was noted as an index sensitive to high training loads and was found to be decreased after strenuous physical activity. Moreover, low CD4+/CD8+ cell ratio is usually related to acute viral diseases and hemophilia. Therefore, improvement of this immunological parameter could contribute to the favorable effects of Lafti L10 on URTI.”
The study used Lallemand Health Solutions’ Lactobacillus helveticus Lafti L10 probiotic strain. The study was funded by Serbian Ministry of Education, Science and Technological Development.
Commenting on the study’s findings, Stéphanie-Anne Girard, PhD, Clinical Program Manager at Lallemand Health Solutions, said: “This clinical study is the fourth trial in healthy adults (the second in athletes) and the results support and reinforce the findings of the previous clinical studies demonstrating the immunological benefits of L. helveticus Lafti L10 supplementation. The positive results indicate that this probiotic strain could help reduce cold-like symptoms by restoring the exercise-induced lowered immune response in active people.”
The researchers recruited 39 elite athletes to participate in their randomized, double-blind, placebo-controlled study. Participants were randomly assigned to receive placebo or probiotic (L. helveticus Lafti L10, 20 billion CFUs per day) for 14 weeks in winter.
Results showed that the duration of URTI episodes in participants in the Lafti L10 group were an average of 4.7 days, compared with 7.25 days in the placebo group. Participants in the Lafti L10 group also experienced significantly fewer symptoms of URTIs, compared with placebo.
On the other hand, there were no differences between the groups for severity and incidence of URTI.
While a significant effect on the CD4+/CD8+ ratio was recorded following Lafti L10 supplementation, compared with placebo, no significant differences between the groups were observed for other immunity markers.
The potential mechanism of action may be linked to an augmentation of the systemic immune system, said the researchers. Other published studies have reported that that oral administration of Lafti L10 may upregulate genes associated with IFN-gamma, which plays a key role in the immune response.
“Indeed, these findings were corroborated with animal studies: the oral administration of Lafti L10 in mouse elicited increase of IFN-gamma secreted both from splenocytes and in serum,” wrote the researchers.
“Future clinical trials should be focused on larger samples of athletes and higher daily dose of Lafti, in order to observe possible positive clinical outcomes of Lafti supplementation (reduction of frequency and/or severity of URTI, debilitation of impact of URTI on training) and provide further clarification of mechanism of Lafti interaction with immune system in athletes,” they concluded.
Source: Applied Physiology, Nutrition, and Metabolism
2016, Volume 41, Issue 7, Pages 782-789, doi: 10.1139/apnm-2015-0541
“Lactobacillus helveticus Lafti L10 supplementation reduces respiratory infection duration in a cohort of elite athletes: a randomized, double-blind, placebo-controlled trial”
Authors: D. Michalickova et al.