RECOVERY AND ELIMINATION OF THE BIOTHERAPEUTIC AGENT, SACCHAROMYCES-BOULARDII, IN HEALTHY-HUMAN VOLUNTEERS

Saccharomyces boulardii (Sb) is a nonpathogenic yeast used to treat in testinal illnesses such as pseudomembranous colitis and antibiotic ass ociated diarrhea. The behavior of this biotherapeutic agent in humans was determined (1) in investigating the effect of dose on the steady-s tate level and recovery and (2) in quantitating the effect of ampicill in on the recovery and elimination profile. As the Sb dose increased, the mean steady-state concentration of Sb increased significantly. The percentage recovery was dose independent. When a single Sb dose was a dministered 24 hr after beginning a course of ampicillin, there was a significant increase (P < 0.01) in both the area under the concentrati on versus time curve and the maximum fecal concentration compared to v alues obtained without ampicillin. Ampicillin increased steady-state r ecovery of the drug about twofold (P < 0.05) and steady-state levels a bout 2.4 times (P < 0.01). These studies have shown that there is a re lationship between the dose and the amount of Sb recovered and that pe rturbation of the GI flora by ampicillin increases steady-state levels of Sb.