Daily probiotic may help prevent upper respiratory tract infections in athletes: Research

Researchers at Loughborough University have revealed that a simple, daily probiotic might help prevent athletes catching colds during their training and competition.

The research, which was published in the (peer-reviewed) International Journal of Sport Nutrition and Exercise Metabolism, indicated that daily consumption of the probiotic drink Yakult is effective in reducing incidence of upper respiratory tract infections in athletes.

Athletes performing prolonged intensive exercise, or with heavy schedules of training and competition, catch more colds because the associated physical and mental stress affects their immune system.

Salivary immunoglobulin A (IgA) is important in preventing viral infections - particularly in the respiratory tract. Levels of this antibody can fall during periods of intensive exercise.

Endurance athletes involved in regular intensive sports training such as cycling, triathlon, middle and long distance running or swimming were divided into two groups. Over a period of 16 weeks, one group of 42 athletes drank Yakult every day and a matching group of 42 had placebo drinks.

At the end of the trial, a lower proportion of probiotic drinkers experienced an episode of the common cold compared to those drinking a placebo (66% v 90%). The average number of cold episodes was also 50% lower in the probiotic drinkers. The results further indicated this benefit was due to the probiotic maintaining levels of salivary IgA.

The athletes drinking the probiotic also experienced significantly fewer days with the gastrointestinal symptoms that are frequently suffered by triathletes and runners.

Prof Michael Gleeson Professor of Exercise Biochemistry in the School of Sport, Exercise and Health Sciences who led the study at Loughborough University commented:

"There is relatively little evidence for the effectiveness of so-called dietary immunostimulants in the athletic population but this study suggests that a probiotic product may help to reduce the risk of infection. Athletes hate the thought of picking up colds as even minor ailments can impair their training and performance or even stop them from competing."

Dr Linda Thomas, Science Director at Yakult UK commented:

"This double-blind, placebo-controlled trial has given further evidence of an immune benefit associated with drinking Yakult. Athletes are an example of healthy people whose lifestyle reduces the ability of their immune system to fight infection."