This study was designed to evaluate safety and tolerability of a range of doses of VE303 in healthy adult volunteers. The study also evaluated pharmacokinetics of intestinal colonization by the VE303 strains and pharmacodynamics of recovery of the gut microbiota after administration of antibiotics followed by a course of VE303.

VE303 is a rationally-defined bacterial consortium candidate being developed for the prevention of recurrent C. difficile infection. VE303 consists of 8 types of clonal human commensal bacteria strains selected for their ability to provide colonization resistance to C. difficile and manufactured under GMP conditions.

Key Inclusion Criteria:

• Subjects who are judged to be in general good health
• Body mass index between 18.5 and 30 kg/m2
• Women either of non-child bearing potential or using a highly effective form of contraception
• Men using a highly effective method of contraception

Key Exclusion Criteria:

• Past or present clinically significant diseases that may affect the outcome of the study
• Taking any medications, herbal preparations, or natural substances, live bacteria products, or food that impacts or alter GI flora
• Use of proton pump inhibitors or other short or long acting antacid medications
• Taking or has received an investigation drug or treatment within 60 days of inpatient admission
• Known allergies to involved study drugs
• Chronic constipation or diarrhea
• History of or active IBD