Benefits of oat β-glucan and sucrose feedings on infection and macrophage antiviral resistance following exercise stress

Murphy EA, Davis JM, Carmichael MD, Mayer EP, Ghaffar A. Benefits of oat beta-glucan and sucrose feedings on infection and macrophage antiviral resistance following exercise stress. Am J Physiol Regul Integr Comp Physiol 297: R1188-R1194, 2009. First published August 19, 2009; doi:10.1152/ajpregu.00396.2009.-Oat beta-glucan can counteract the exercise-induced increased risk for upper respiratory tract infection (URTI) in mice, which is at least partly mediated by its effects on lung macrophages. Substantial evidence in humans indicates that carbohydrate-containing sports drinks can offset the decreased immune function associated with stressful exercise. However, no studies in animals or humans have directly examined their effects on URTI using a controlled virus-challenge model. We examined the effects of sucrose feedings alone and in combination with oat beta-glucan on susceptibility to infection and on macrophage antiviral resistance in mice following stressful exercise. These effects were also examined in rested, nonimmunocompromised control mice. Mice were assigned to one of four groups: H2O (water), sucrose (S), oat beta-glucan (O beta G), and sucrose + oat beta-glucan (S + O beta G). O beta G and S treatments consisted of a solution of 50% O beta G and 6% sucrose, respectively, and were administered in drinking water for 10 consecutive days. Exercise consisted of a treadmill run to fatigue performed on three consecutive days. Mice were then intranasally inoculated with a standardized dose of herpes simplex virus 1 (HSV-1) and monitored for morbidity and mortality for 21 days. Additional mice were used to determine macrophage antiviral resistance. In the exercise experiment, S, O beta G, and S + O beta G all reduced morbidity (P < 0.05), while only S + O beta G reduced mortality (P < 0.05). Macrophage antiviral resistance was also increased in S, O beta G, and S + O beta G treatments (P < 0.05). In resting controls, S and S + O beta G reduced morbidity and mortality (P < 0.05) and showed a trend toward increased macrophage antiviral resistance. There was no significant additive effect of S and O beta G in either control or exercised animals. These data extend our previous work on the benefits of oat beta-glucan to show that sucrose feedings have similar effects on susceptibility to respiratory infection and macrophage antiviral resistance in both resting controls and following exercise stress.