Dose-Response Effect of Saccharomyces cerevisiae UFMG A-905 on the Prevention of Asthma in an Animal Model.

Abstract

Probiotics should be administered in adequate amounts to confer health benefits. Probiotic dose-response studies are still missing. Saccharomyces cerevisiae UFMG A-905 prevented asthma development; however, the ideal dose has not been investigated. We evaluated the optimal dose and administration regimen of S. cerevisiae UFMG A-905 in the prevention of asthma. Male Balb/c mice were sensitized intraperitoneally with ovalbumin (OVA) and challenged with OVA intranasally. Mice received, via gavage, daily or alternate-day S. cerevisiae UFMG A-905. In daily regimen, different concentrations (107, 108, or 109CFU/mL) were given 10days before OVA sensitization and during challenges. In alternate-day regimen, a concentration of 109CFU/mL was administered three times per week for 5weeks, starting 2weeks prior to the first sensitization. After the last challenge, in vivo bronchial hyperresponsiveness and airway and lung inflammation were assessed. OVA-challenged mice, when compared to saline-challenged mice, presented a significant increase in bronchial hyperresponsiveness and airway and lung inflammation. Daily and alternate-day administration of 109CFU/mL of S. cerevisiae UFMG A-905 significantly reduced bronchial hyperresponsiveness; lower concentrations of S. cerevisiae UFMG A-905 did not significantly reduce bronchial hyperresponsiveness. Daily regimen with the highest concentration significantly reduced total cell number, eosinophil count in the BAL, and the levels of IL-4, IL-5, and IL-13. Daily administration of S. cerevisiae UFMG A-905 at 107 and 108CFU/mL and alternate-day regimen did not significantly decrease airway and lung inflammation. S. cerevisiae UFMG A-905 led to a significant attenuation of bronchial hyperresponsiveness and lung inflammation in a dose-dependent manner.