It is well reported that performance athletes have a high prevalence of gastrointestinal complaints, including nausea, cramps, vomiting and diarrhea. This is said to be due to changes in blood flow because of increased demand from muscles and the heart, which in turn reduces blood in the intestines. Less blood in your guts means that the permeability of the intestine is affected and this can increase an athlete’s susceptibility to infectious.
“Thus, to reduce exercise-induced [gastrointestinal] permeability and its associated symptoms and illnesses, nutritional solutions like probiotic supplementation may be of relevance for athletes and also a real challenge for the probiotic industry to develop bio-effective products,” explained researchers led by Manfred Lamprecht from the Medical University of Graz.
Zonulin
For their new study, the Austrian scientists focused on levels of a particular protein called zonulin, which plays a key role in the integrity of structures in the intestine called tight junction: Increased zonulin levels is indicative of a ‘leak’ in the intestine, they said, which would allow “antigens to pass from the intestinal milieau, challenging the immune system to produce an immune response and subsequent inflammation and oxidative stress”.
Daily supplements for 14 weeks of a blend of probiotic strains, however, were associated with decreases in zonulin concentrations in the feces of trained men.
“Our data support the hypothesis that an adequate probiotic supplementation can improve intestinal barrier function, redox hemostasis and low-grade inflammation in men under sustained exercise stress,” wrote the researchers in the Journal of the International Society of Sports Nutrition.
Study details
For the new study, Dr Lamprecht and his co-workers recruited 23 trained men with an average age of 38 to participate in their randomized, double-blinded, placebo-controlled trial. Participants were randomly assigned to received either the probiotic blend (EcologicPerformance, Winclove b.v., Amsterdam. The product is also branded as OMNi-BiOTiC Power) or placebo for 14 weeks.
The probiotic blend contained Bifidobacterium bifidum W23, Bifidobacterium lactis W51, Enterococcus faecium W54, Lactobacillus acidophilus W22, Lactobacillus brevis W63, and Lactococcus lactis W58.
Results showed that zonulin levels decreased significantly in the probiotic group, compared with placebo, from values slightly above normal into normal ranges.
In addition, markers of inflammation tended to be lower in the probiotic group, but not statistically significant.
There were no differences between the groups for MDA levels. Malondialdehyde (MDA) is a reactive carbonyl compound and a well-established marker of oxidative stress.
“The probiotic treatment decreased Zonulin in feces, a marker indicating enhanced gut permeability,” wrote Dr Lamprecht and his co-workers.
“These results demonstrate promising benefits for probiotic use in trained men.”
Source: Journal of the International Society of Sports Nutrition
2012, 9:45 doi:10.1186/1550-2783-9-45
“Probiotic supplementation affects markers of intestinal barrier, oxidation, and inflammation in trained men; a randomized, double-blinded, placebo-controlled trial”
Authors: M. Lamprecht, S. Bogner, G. Schippinger, K. Steinbauer, F. Fankhauser, S. Hallstroem, B. Schuetz, J.F. Greilberger