Double-blinded, randomised controlled trial to evaluate the clinical efficacy of a single dose of oral capsule-administered faecal microbiota transplantation (FMT) for carbapenemase-producing Enterobacteriaceae (CPE) intestinal decolonisation compared with placebo. Primary outcome is the proportion of patients successfully decolonised of CPE intestinal carriage at 12 weeks after FMT treatment compared with placebo.

Inclusion Criteria:

• Admitted as inpatient at the study site at the time of screening.
• Aged ≥21 years at the time of screening.
• Sufficiently ambulant to return for outpatient clinic study visit.
• Detection of CPE (result reported by clinical microbiology laboratory).
• Ability to provide informed consent.
• Females of childbearing potential who are sexually active with a non-sterilised male partner must agree to use at least one method of effective contraception for the duration of the trial.
• Colonisation of the gastrointestinal tract with CPE, confirmed by at least one positive rectal swab taken ≤7 days before randomisation (direct PCR testing using Xpert Carba-R, performed by study team independent of the hospital screening protocol).
• Ability to swallow "safety test" capsule (one test capsule given during pre-randomisation evaluation).
• Antibiotics ceased for at least 48 hours before pre-randomisation evaluation.
• Negative urine pregnancy test for pre-menopausal women taken ≤7 days before randomisation

Exclusion Criteria:

• Presence of acute diarrhoeal illness (e.g. gastroenteritis, C. difficile colitis) or chronic diarrhoeal illness (e.g. irritable bowel syndrome or inflammatory bowel disease, unless they are in remission for at least 3 months prior to enrolment).
• Current use or planned use of an investigational drug within 3 months of enrolment.
• Presence of significant immunosuppression, including but not limited to: use of monoclonal antibody, use of prolonged steroids equivalent to prednisolone dose of ≥20mg/day for ≥28 days, solid organ transplantation, bone marrow transplantation, HIV infection with CD4 count of ≤200, bone marrow transplant, ongoing chemotherapy or radiation therapy, and congenital immunodeficiency.
• Oropharyngeal dysphagia, significant oesophageal dysphagia, or other inability to swallow.
• History of surgery altering gastrointestinal anatomy (e.g. colostomy, colectomy).
• Ileus or small bowel obstruction.
• Risk of aspiration.
• History of gastroparesis.
• Severe food allergy (anaphylaxis or anaphylactoid reaction).
• Adverse event attributable to previous FMT.
• Those who are pregnant or plan to be pregnant within 3 months of enrolment.
• Those who are breastfeeding or plan to breastfeed during the trial.
• Life expectancy <3 months.

Study subjects will be randomised to either FMT-capsules or placebo (subject and investigator-blinded) immediately prior to capsule administration. Subjects who are randomised to FMT by capsule will receive 30 FMT-containing capsules under direct-observed therapy. Subjects who are randomised to placebo capsules will receive 30 placebo capsules under direct-observed therapy.