Acid tolerance and fecal recovery following oral administration of Saccharomyces cerevisiae.

Probiotic micoorganisms to be used os biotherapeutic agents have to resist the rigors of theupper human gastrointestinal tract. In this study we evaluated the acid tolerance in vitro and the fecal recovery in vivo after oral administration of a Saccharomyces cerevisiae strain to healthy volunteers. At the lowest pH value (pH 7.0 the release of S. cerevisiae in buffer solutions increased. The selected yeast strain showed good tolerance to low pH wihich mimic the gastric envitornment the feces of 6 (37.5%) of the 16 healthy, treated volunteers. Based on the results of the present experiments the yeast studied can be considered a strain that tolerates adverse conditions comparable to those of the human gastrointestinal tract, and when administered orally may colonize the bowel of healthy volunteers adn even replace resident Candida species.