A Study of Safety of PBCLN-003 Following Antibiotic Therapy in Subjects With C.Difficile-associated Diarrhea

Inclusion Criteria: * Enrollment episode of CDAD diagnosed based on \> 3 loose stools per day and detection of CD toxin by nucleic acid amplification tests (NAAT), EIA or GDH * Mild to moderate CDAD during enrollment episode (per Society of Hospital Epidemiologists of America (SHEA)/lnfectious Disease Society of America(ISDA) criteria) * Current therapy with standard of care antibiotics for recurrent CDAD(vancomycin, metronidazole, fidaxomicin) * BMI \> 18.5 and \< 40 * Age 18 years or older * Agreement to adhere to the study protocol * Informed consent is obtained * Women who are capable of bearing children must have a negative pregnancy test at the time of screening * Female subjects of childbearing potential must use birth control (defined as oral or injectable contraceptives, intrauterine devices, surgical sterilization or a combination of a condom and spermicide) during the study period and for up to 8 weeks after the first drug of study. Exclusion Criteria: * Severe CDAD during enrollment episode (per SHEA/ISDA criteria) characterized as follows: * History of five (5) or more recurrences of CDAD within the past 12 months prior to potential study enrollment * History of fecal microbiome transplant or other microbiome directed experimental intervention for CDAD * History (ever) of CD complicating inflammatory bowel disease (Crohn's disease, ulcerative colitis), or history of bowel resection surgery (other than uncomplicated appendectomy) or history of other infectious diarrhea or diarrhea of unknown etiology since the initial episode of CDAD * Clinically immunocompromised due to any primary immune or autoimmune deficiency, as a result of chronic disease, cancer or medication used to treat these diseases * Initiating a new diet or weight loss amounting to 10% within two weeks prior to date of study entry * Enrolled in another clinical study for the therapy of CDAD or affecting nutritional management during the study period * Enrolled or has been enrolled in another experimental (IND) study within two weeks prior to date of study entry * Is pregnant or lactating * History of swallowing difficulties, including dysphagia or odynophagia for liquids or solids * Use of any Probiotics (any formulation) within the two weeks prior to date of study entry * New, or a change in the consumption of the following prescription medications or over-the-counter (OTC) medications within two weeks prior to date of study entry: * Proton pump inhibitors (for example: Prilosec®, Nexium®) * Histamine-2 receptor antagonists (for example: Zantac®, Pepcid®) * Consumption of the following prescription medications during the current enrollment episode: • Bezlotuxamab/Zinplava®