Purpose: The aim of the current study was to investigate the effects of the probiotic Escherichia coli strain Nissle 1917 (EcN) on the exercise-induced disruption of gastrointestinal (GI) integrity and the associated release of damage and inflammatory markers.
Methods: After a pre-performance test, 19 untrained subjects (aged 18-35 years) passed two identical exhaustive treadmill exercise tests in an intensity corresponding to 60-80% VO2max in a test-retest design. The exercise tests were separated by a time period of 4 weeks. During this period, all subjects ingested 5 ml of an EcN suspension daily. Serum samples were taken before, immediately following and 3 h after both exercise tests. They were analyzed for indicators of GI integrity (zonulin; claudin-3; LPS), various damage and redox markers (I-FABP, GOT; GPT; TBARS) and inflammatory parameters (hsCRP; leucocytes). GI complaints were evaluated by a questionnaire.
Results: The intake of EcN resulted in a significantly lower increase in I-FABP and TBARS after exercise (p < 0.05). In contrast, no effect of EcN supplementation was found for hsCRP and leucocyte numbers. Similarly, no differences were found for levels of zonulin and claudin-3. Exercise-associated GI complaints were not affected by the probiotic supplement.
Conclusion: The probiotic EcN reduced the exercise-associated increase in oxidative stress. This antioxidative mechanism probably leads to a reduction of GI epithelial damage after exhaustive exercise. The lack of EcN effects on other markers of GI permeability and systemic inflammation is most likely due to an inadequate exercise load, with rather small and insignificant exercise effects on these parameters.
Keywords: Escherichia coli strain Nissle 1917; Exercise; Gastrointestinal tract; Intestinal fatty acid binding protein; Probiotic.