What is a fecal (faecal) transplant and how is it performed?

What is Faecal Transplant and How is it Done

Faecal microbiota transplantation (FMT) is the transfer of minimally manipulated faeces from a rigorously screened healthy donor to a patient's gastrointestinal tract, primarily to treat recurrent Clostridioides difficile infection by restoring beneficial gut bacteria. 1

Definition and Purpose

FMT involves delivering faecal microorganisms from a healthy donor into the intestinal tract of a patient to correct dysbiosis (disrupted gut bacteria balance). 1 The procedure aims to restore phylogenetic diversity and microbiota typical of a healthy individual, with the transplanted microbial communities persisting durably after administration. 1

While donor stool contains approximately 10^11 bacterial cells per gram, it also includes other components such as colonocytes, archaea, viruses, fungi, and metabolites that may contribute to therapeutic effects. 2

Primary Clinical Indication

FMT should be offered to all patients with two or more recurrences of C. difficile infection (CDI). 1 It can also be considered for first recurrence or as an adjunct in refractory CDI. 1 The procedure achieves cure rates of 87-90% for recurrent CDI, with some studies reporting up to 100% success. 1, 3

For other conditions including inflammatory bowel disease, irritable bowel syndrome, and metabolic syndrome, FMT remains investigational and should only be performed in research settings. 1, 4

Donor Selection and Screening

Donor Exclusion Criteria

Potential donors are excluded if they have: 1

• Infectious disease history: Recent infections, blood-borne viruses (HIV, hepatitis B/C), tuberculosis
• High-risk behaviors: Illicit drug use, high-risk sexual behaviors, tattoos/piercings/needlestick injuries within 6 months
• Gastrointestinal conditions: IBD, IBS, chronic diarrhea/constipation, coeliac disease, bowel surgery
• Systemic conditions: Autoimmune diseases, metabolic disorders (diabetes, obesity), malignancy
• Medication use: Antimicrobials, proton pump inhibitors, immunosuppression, chemotherapy within 3 months
• Recent exposures: Live vaccines within 6 months, travel to tropical countries within 6 months

Required Screening Tests

Blood screening includes: 1

• Full blood count with differential
• Creatinine and electrolytes
• Liver enzymes (albumin, bilirubin, aminotransferases)
• C-reactive protein
• Blood-borne virus testing (HIV, hepatitis B/C)

Stool screening includes: 1

• C. difficile PCR
• Bacterial culture/PCR for Campylobacter, Salmonella, Shigella
• Shiga toxin-producing E. coli PCR
• Multi-drug resistant bacteria (carbapenemase-producing Enterobacteriaceae, extended spectrum beta-lactamases)
• Ova, cysts, and parasite analysis including Microsporidia
• Faecal antigens for Cryptosporidium and Giardia
• Helicobacter pylori faecal antigen
• Norovirus and rotavirus PCR

For frozen FMT, donors must complete screening both before and after the donation period, with FMT kept in quarantine until repeat screening confirms ongoing suitability. 1

FMT Preparation Protocol

Stool Collection and Processing

Donor stool must be processed within 6 hours of defaecation. 1 Collection should follow these principles: 1

• Use clean, sealable containers with proper hand hygiene
• Transport to processing site as soon as possible (store at 4°C if brief delay necessary)
• Use ≥50 grams of stool per FMT preparation 1

Preparation Method

Mix stool 1:5 with sterile 0.9% saline to create the initial faecal emulsion. 1 For frozen preparations, add cryoprotectant such as glycerol. 1 Homogenisation and filtration should occur in a closed disposable system. 1

Both aerobically and anaerobically prepared FMT are considered suitable for treating recurrent CDI, with aerobic preparation being simpler and equally efficacious. 1

Administration Routes

Upper Gastrointestinal Delivery

Upper GI administration is appropriate via nasogastric, nasoduodenal, or nasojejunal tube, or through upper GI endoscopy. 1 Key considerations: 1

• Administer no more than 100 mL of FMT to the upper GI tract
• Consider prokinetics (metoclopramide) prior to administration
• Use with caution in patients at risk of regurgitation or with swallowing disorders

Lower Gastrointestinal Delivery

Colonoscopic administration with preferential delivery to the caecum or terminal ileum appears to give the highest efficacy rates. 1 Flexible sigmoidoscopy or enema can be used when colonoscopy is not possible. 1

Encapsulated FMT

Capsulised FMT is recommended as a treatment option where available, following standard protocols. 1 This oral route eliminates the need for endoscopy or tube placement. 5

Pre-FMT Patient Preparation

Antibiotic Management

Ensure FMT is preceded by treatment of CDI with appropriate antibiotics for at least 10 days. 1 Then: 1, 5

• Maintain a minimum 24-hour washout period between the last antibiotic dose and FMT 1
• Stop antibiotics 1-3 days before conventional FMT (1 day if bowel purge given, 3 days without purge) 5
• Use suppressive anti-CDI antibiotics (vancomycin) to bridge until FMT administration 5

Infection Control

Apply best practices for CDI transmission prevention throughout FMT administration, including nursing with enteric precautions and sporicidal treatment of endoscopes. 1

Contraindications and Special Populations

Offer FMT to all patients regardless of health status, except those with known anaphylactic food allergy. 1 However: 5

• Avoid FMT in severely immunocompromised patients (active chemotherapy, neutropenia, untreated HIV with CD4 <200, recent CAR-T or stem cell transplant)
• Consider carefully in patients requiring frequent or long-term antibiotics, as ongoing antibiotics diminish FMT efficacy
• Inform IBD patients about small risk of disease exacerbation after FMT 1

Post-FMT Management

Follow-up FMT recipients for at least 8 weeks to establish efficacy and monitor for adverse events. 1 Key points: 1, 5

• Do not test for cure by absence of C. difficile unless patient has persistent symptoms
• Inform patients about possibility of self-limiting gastrointestinal symptoms
• Serious adverse events are rare
• Educate on antimicrobial stewardship, as antibiotic use within 8 weeks post-FMT significantly increases recurrence risk 5

Management of FMT Failure

Offer one or more repeat FMTs after initial clinically assessed FMT failure. 1 Approximately 10-30% fail single FMT; options include repeat FMT with fresh donor stool or chronic low-dose vancomycin suppression. 5

Safety Monitoring

Monitor, notify, and investigate all adverse events and reactions related to FMT. 1 This is particularly important given documented cases of patient morbidity and mortality from FMT-related pathogen transmission, emphasizing the critical importance of rigorous donor screening. 1