Survival of Saccharomyces boulardii in the rat gastrointestinal tract and effects of dietary fiber

Abstract

The present study was directed to determine the sites of destructive metabolism of the biotherapeutic yeast Saccharomyces boulardii and the influences of dietary fiber on survival. Both single dose and steady state experiments implicate the lower bowel as an important influence in the metabolic loss of viability of S. boulardii in rats. Studies in rats revealed that diets containing psyllium hydrocolloid or polycarbophil increased fecal steady state levels of S. boulardii by 4.3-fold and 3.2-fold, respectively, compared to levels in fiber-free diet fed animals. Pectin and alginic acid had no effect. Psyllium fiber increased steady state recovery in all experiments in which the S. boulardii was given orally (p < 0.04) but did not when S. boulardii was given via a cecal cannula, suggesting that this fiber may act in the terminal ileum at steady state. Only specific types of dietary fiber can increase the number of viable S. boulardii passing through the gastrointestinal tract at steady state dosing.