Stimulating whole saliva affects the response of antimicrobial proteins to exercise

This study investigated the salivary secretion rates of antimicrobial proteins in response to prolonged, exhaustive exercise in both stimulated ( STIM ) and unstimulated ( UNSTIM ) saliva flow sample methods. Twenty‐four trained men cycled for 2.5 h at 60%V ˙ O 2 m ⁢ a xand then to exhaustion at 75%V ˙ O 2 m ⁢ a x. Timed collections of whole saliva were made before exercise, mid‐exercise, at the end of the moderate exercise bout and post‐exhaustive exercise. After each UNSTIM collection, a STIM sample was collected following chewing flavored gum for 1 min. Saliva was analysed for lysozyme, α‐amylase and salivary immunoglobulin A (s‐ IgA ), and secretion rates were calculated. Saliva flow was 156% higher in STIM compared with UNSTIM ( P  < 0.001) and decreased with exercise in STIM only ( P  < 0.001). Exercise increased lysozyme and α‐amylase levels and secretion rates were 144% higher and 152% higher in STIM compared with UNSTIM for lysozyme and α‐amylase, respectively (all P  < 0.001). S‐ IgA concentration ( P  < 0.05) and secretion rate ( P  < 0.001) increased with exercise but were both lower in STIM compared with UNSTIM ( P  < 0.001). In conclusion, a STIM saliva flow collection during exercise by chewing flavored gum increased the quantity of saliva and the secretion of lysozyme and α‐amylase, but had a limited impact on the secretion of s‐ IgA .