Fecal Microbiota Transplantation for the Treatment of ICU Delirium

Summary

Delirium in the intensive care unit (ICU) is a prevalent and serious neurological complication among critically ill patients, with large multicenter studies reporting an incidence of 30% to 80%, particularly in those requiring mechanical ventilation. Delirium is not only associated with prolonged ICU and hospital stays but also with increased morbidity and mortality. Notably, up to 40% of survivors suffer from persistent cognitive dysfunction that may last for months or even years. Despite current standard pharmacological interventions-such as haloperidol and second-generation antipsychotics-failing to demonstrate significant clinical benefit in phase III trials, non-pharmacological strategies remain challenging to implement due to environmental and operational constraints within the ICU. This unmet clinical need underscores the imperative to develop novel, effective therapeutic approaches.

Emerging evidence suggests that ICU-acquired gut microbiota dysbiosis plays a pivotal role in the pathogenesis of delirium. Dysbiosis can compromise intestinal barrier integrity, promoting systemic inflammation and increasing susceptibility to various forms of delirium, including acute illness-related and postoperative types. These effects are likely mediated through the "gut-microbiota-brain axis," which may represent a central mechanism underlying neurocognitive dysfunction in critical illness.

Preclinical studies have demonstrated that fecal microbiota transplantation (FMT) can restore microbial balance and exert beneficial effects on neurological function. FMT has shown promise in ameliorating cognitive deficits in models of Alzheimer's disease, chronic cerebral hypoperfusion, traumatic brain injury, and chronic unpredictable mild stress (CUMS). Clinically, FMT has been associated with cognitive improvement in patients with dementia, recurrent Clostridioides difficile infection, and sepsis-associated encephalopathy. With expanding applications in both gastrointestinal and extraintestinal disorders, FMT has emerged as a transformative therapeutic modality, supported by robust short- and long-term safety and efficacy data.

This study aims to evaluate whether FMT can alleviate delirium severity, correct gut microbiota dysbiosis at 0, 72, and 120 hours post-enrollment, attenuate intestinal barrier dysfunction, reduce systemic inflammation and disease severity, shorten ICU length of stay, and lower rates of ICU mortality, in-hospital mortality, and 28-day all-cause mortality-ultimately positioning FMT as a potential breakthrough intervention for ICU delirium.

Conditions

• Delirium

Interventions

OTHER

Intestinal microbiota suspension

FMT was administered via a nasojejunal tube daily for three consecutive days, between 11:00 and 13:00. Each 50-100 mL dose, derived from 100-150 g of adolescent donor feces diluted to 300 mL. Patients fasted for 2 hours before and after FMT, except for permitted water intake. Intravenous antibiotics were withheld unless active infection was confirmed. If pathogens were considered colonizing and the patient remained stable, systemic antibiotics were avoided. Localized treatments, such as nebulized antibiotics, were allowed as needed. All antibiotic use required clinical justification and individual assessment to minimize interference with FMT. Oral antibiotics were prohibited after FMT initiation to protect engraftment and microbial integrity.

Sponsors & Collaborators

• Union Hospital, Tongji Medical College, Huazhong University of Science and Technology

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Max Age

80 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2026-03-18

Primary Completion

2028-12-30

Completion

2028-12-30

Countries

• China

Study Locations