SACCHAROMYCES-BOULARDII ENHANCES RAT INTESTINAL ENZYME EXPRESSION BY ENDOLUMINAL RELEASE OF POLYAMINES

Saccharomyces boulardii is a yeast widely used in humans for the preve ntion and treatment of infectious enteritis and Clostridium difficile- associated enterocolopathies. After oral administration to human volun teers or growing rats, S. boulardii enhances markedly the expression o f intestinal enzymes as well as the production of the polymeric immuno globulin receptor by mechanisms that remain unknown. We have analyzed the role of the yeast polyamines as potential mediators in the intesti nal trophic response. In weanling rats (d 20 to d 30), a daily dose of 100 mg of lyophilized S. boulardii produced significant (p < 0.025) i ncreases in sucrase (157%) and maltase (47%) activities. This dose cor responded to a total oral load of 678 nmol of polyamines per day (sper midine: 376 +/- 32, spermine: 293 +/- 26, putrescine: 9.5 +/- 1.4 nmol /100 mg). Spermine, given orally to growing rats at doses nearly equiv alent (500 nmol) to the load of polyamines provided by the yeast (678 nmol), reproduced similar enzymatic changes, including a 2.5-fold indu ction of sucrase, and enhanced maltase activity (+24%). Spermidine and spermine concentrations measured in the jejunal mucosa of treated rat s were increased over matched controls by 21.4% (p < 0.005) and 21.9%, respectively (p < 0.002). After being centrifuged and filtered to dis card residual yeast cells, 2-mL samples of jejunal and ileal fluid col lected from S. boulardii-treated rats by intestinal flushing contained higher levels of spermidine (48 and 60%) and spermine (150 and 316%) than did control rats. Our data indicate that lyophilized S. boulardii exerts trophic effects on the small intestine that are likely mediate d by the endoluminal release of spermine and spermidine.