Fatiguing exercise has been associated with a decrease in certain functions of neutrophils, whereas moderate exercise has generally been associated with an increase. Consumption of oat β-glucan (OβG), a soluble fiber and mild immune system enhancer, may offset the immunosuppression associated with intense training and perhaps further enhance the benefits of moderate exercise.
Purpose: To test the effects of OβG consumption on neutrophil function and number after both moderate and fatiguing exercise.
Methods: Male mice were assigned to one of six treatment groups. Fatiguing exercise mice (Ftg-OβG and Ftg-H2O) ran to volitional fatigue on a treadmill for three consecutive days, and moderate exercise mice (Mod-OβG and Mod-H2O) ran for six consecutive days for 1 h. Control mice (Con-OβG and Con-H2O) were exposed to the treadmill environment but did not run. OβG was consumed in the drinking water (~0.6 mL·d−1) for 10 consecutive days. After rest or exercise on the last day of training, mice were given a 1-mL i.p. injection of thioglycollate. Mice were sacrificed 3 h later; neutrophils were harvested from the peritoneal cavity and counted, and their respiratory burst activity was measured using flow cytometry.
Results: Both moderate exercise and OβG increased neutrophil burst activity, whereas fatiguing exercise had no effect. Neutrophil number was increased by fatiguing exercise and OβG, but not moderate exercise. There were no additive effects of exercise and OβG on either of these variables.
Conclusion: These data suggest that although not additive in their effects, both OβG and exercise can alter overall neutrophil respiratory burst activity (number and/or function), but only OβG increased both number and function, which may have important ramifications for defense against infection.