EFFECTS OF OAT BETA-GLUCAN ON SUSCEPTIBILITY TO INFECTION AND MACROPHAGE ANTI-VIRAL RESISTANCE FOLLOWING STRENUOUS EXERCISE

Abstract

Intense exercise is associated with increased risk for URTI. Consumption of oat beta-glucan (Obg), a soluble fiber, is a mild immune system enhancer that may offset immune suppression with intense training. PURPOSE: We studied the effects of Obg on susceptibility to infection following short-term exhaustive exercise training using our mouse model of respiratory infection (Davis et.al. J. Appl. Physiol. 83 (5): 1461-6 1997). Macrophage (Mo) anti-viral resistance was also determined as a potential mechanism of this effect. METHODS: Male CD-1 mice (n = 96) were randomly assigned to one of four groups. Exercise mice (EX-obg and EX-h2o) ran to volitional fatigue on a treadmill for 3 consecutive days at 36m/min, 8% grade. Control mice (C-obg and C-h2o) were exposed to the same environment, but remained in their cages throughout the exercise period. Obg was consumed in the drinking water (3.6mg/day) (EX-obg and C-obg) for 10 consecutive days prior to virus inoculation. Following rest or exercise on the last day of training, mice were intra-nasally inoculated with herpes simplex virus-1 (HSV-1). They were monitored twice daily for morbidity and mortality for 21 days. Additional mice (n = 72) were sacrificed following exercise; peritoneal macrophages were obtained via i.p. lavage and assayed for anti-viral resistance to HSV-1. RESULTS: EX increased morbidity by 25% and mortality by 17% (P < 0.05), and ingestion of Obg prevented this increase in morbidity and mortality (P < 0.05). EX also decreased Mo anti-viral resistance (P < 0.05) and Obg prevented this decrease (P < 0.05). CONCLUSION: These data suggest that consumption of Obg may offset the increased risk of infection during heavy training, and that this maybe mediated, at least in part, by an increase in Mo anti-viral function.