Scientists from University of Otago and the Chiefs Rugby Franchise in New Zealand report that a commercial supplement containing Lactobacillus gasseri, Bifidobacterium bifidum, and B. longum (Probiotica P3 by Nutra-life) was also effective in reducing the duration of infections in the rugby players.
“The evident reduction in illness incidence found in the present study suggests probiotics may be a useful nutrition supplement for elite rugby union players during the season,” wrote the researchers in the Journal of Science and Medicine in Sport.
“Probiotics can provide an improvement in resistance to common illness resulting in less training and competition missed/impaired by illness, overall enhancing athletic performance.”
The results could be of interest to other contact team sports, which involve consistent close physical contact with each other. This means that if one player becomes ill, there’s an increased risk that his or her team-mates will also become ill.
According to the FAO/WHO, probiotics are defined as "live microorganisms which when administered in adequate amounts confer a health benefit on the host".
Brylee Haywood and her co-workers recruited 30 rugby union players and randomly assigned them to either the probiotic group (daily dose of three billion colony forming units) or placebo for four weeks. Participants then had a four week ‘washout’ period before crossing over to the other intervention.
Results showed 53% of participants experienced a single episode of the common cold (upper respiratory tract illness) or stomach or gut upset (gastrointestinal) in the probiotics group, while 80% of participants in the placebo group experienced such illness episodes.
The duration of the illness was also significantly reduced in the probiotic group (3.4 days), compared with placebo (5.8 days). No differences in the severity of the symptoms were reported between the two groups.
While the researchers stated that the beneficial effects of probiotics are possibly via a stimulation of the immune cells they did not test for immune markers in the participants.
“These findings constitute an important benefit to rugby union players partaking in intense training and competition schedules,” wrote the researchers. “Episodes of illness often occur during heavy exercise training periods, and it interrupts training sessions and can hinder performance during competition.
“The demand for players to perform on a daily basis is high as selection for starting squads for competition are based on training performance. Thus it is important for rugby union players to find practical ways to enhance their immune system to avoid performance impairment as a result of illness.”
Source: Journal of Science and Medicine in Sport
Volume 17, Issue 4, Pages 356-360, doi: 10.1016/j.jsams.2013.08.004
“Probiotic supplementation reduces the duration and incidence of infections but not severity in elite rugby union players”
Authors: B.A. Haywood, K.E. Black, D. Baker, J. McGarvey, P. Healey, R.C. Brown