Inclusion Criteria:
1. Subject is aged ≥18 and ≤45 years and in good health;
2. Body mass index (BMI) ≥18.0 and \<30.0 kg/m2;
3. Subject has adequate understanding of the procedures of the study and is able and willing to abide strictly thereby;
4. Subject is able to communicate well with the investigator, is willing to follow hygienic measures and instructions;
5. For women of childbearing potential: subject agrees to use adequate contra-ception (see Appendix D for the different adequate contraception methods for this study) and not to breastfeed for the duration of the study;
6. Subject has signed informed consent.
Exclusion Criteria:
1. Any physical or psychiatric illness or conditions that could threaten or com-promise the health of the subject during the study, influence their ability to par-ticipate in the trial or interfere with the interpretation of the study results, as de-termined by the trial physician;
2. Use of systemic (IV or oral) antibiotics within three months prior to screening; other microbiota influencing medication (that could influence the trial, based on the Investigator's opinion) within 1 month prior to screening visit. Prior use of topical antibiotics is permitted if there is no clinically relevant systemic ex-pected following assessment of the trial physician and are expected to be dis-continued during the start of the first study activity.
3. Has had a recent hospitalization (e.g. 3 months prior to screening) and/or has someone in immediate social circle who is frequently hospitalized (≥3 times in a 12-month period) or frequently exposed to hospital settings (≥ one time a month, e.g. dialysis units);
4. Regular use (defined by more than once weekly) of proton-pump inhibitors or H2-blockers during one month prior to screening;
5. Chronic use of immunosuppressive drugs, e.g. systemic corticosteroids or other immune modifying drugs (with exception of oral anti-histamines and top-ical/inhaled corticosteroids);
6. Positive HIV, Hepatitis B or C screening tests;
7. Known immunodeficiency disorders;
8. The use of strong P-glycoprotein-inhibitors (like ciclosporin, ketoconazole, erythromycin, clarithromycin, verapamil and amiodaron) during the trial;
9. Known allergy to vancomycin, clindamycin, fidaxomicin (and macrolides), or metronidazole;
10. Any known significant allergy against the excipients of C. difficile inoculum or inability to swallow capsules;
11. Known gastro-intestinal disease including but not limited to inflammatory bow-el diseases (Crohn's disease, Colitis ulcerosa), a history of bowel resection or any other gastro-intestinal surgery which has significantly changed the ana-tomical structure or physiological function of the gastro-intestinal tract, bile ac-id secretion abnormalities, constipation defined by bowel movements less than every second day or chronic use of laxatives;
12. Positive fecal culture or PCR with toxigenic or non-toxigenic Clostridioides spp. or SSYC (Salmonella spp., Shigella spp., Yersinia spp. or Campylobac-ter spp.) at screening, or recent (\<14 days) history of diarrhoea (i.e. as ≥3 loose stools (Bristol stool scale 6-7) in 24 hours);
13. Any condition that would put household members or close contacts at a great-er risk for transmission e.g. no access or use of flush toilet;
14. Individuals living, working or having close contact with people who belong to vulnerable populations such as hospitalized patients, pregnant women, im-mune compromised individuals, children younger than 2 years, residents of nursing homes, elderly older than 70 years of age, or any person with a medi-cal condition at risk of developing severe CDI.
15. Individuals working in food preparation;
16. Individuals having close contact with healthcare personal/individuals working in food preparation;
17. For women of childbearing potential; a positive serological pregnancy test at screening or lactating at screening/ during the trial;
18. History of drug or alcohol abuse interfering with normal social functioning in the period of one year prior to study onset, positive urine toxicology test for il-licit drug use at screening;
19. Receipt of another investigational agent within 90 days prior or 60 days after C. difficile ingestion;
20. Any condition or situation that could influence the independent consent of par-ticipant (e.g. being a direct colleague or family member of study personnel).
