A Phase 1/2 interventional study of Synbiotic and Standard of Care (SOC) in Critical Illness, sponsored by University of Calgary. Not yet recruiting at 1 site in Canada. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-10.
Sponsored by University of Calgary · Phase 1/2, Interventional, and Prevention
Patients requiring life support therapies in intensive care units are at very high risk of hospital-acquired infections. An important source of these infections is the accumulation of pathogenic bacteria in the microbiome of their gut. We hypothesize that treatment with an enteral synbiotic (combination of probiotic and prebiotic), which has been specifically designed to combat pathogen colonization in the gastrointestinal tract, will be safe and effective to reduce pathogen levels in the gut, and potentially reduce infections.
We are conducting a phase 1b randomized, open-label, controlled trial to assess safety biological efficacy of enteral synbiotic therapy to reduce gastrointestinal enteropathogen colonization in adult critically ill patients.
Enteropathogen colonization of the gut microbiome in critically ill patients is associated with adverse outcomes. Observational studies have consistently reported that gut colonization with enteropathogens including Enterobacterales (e.g. Klebsiella spp., E. coli, Enterobacter spp., and others) and Enterococcus spp. (e.g. E. faecium) is associated with increased risks of hospital-acquired infections, death, organ dysfunction severity, prolongation of life support, and hospitalization. Mechanistically, gut enteropathogen colonization has been shown to contribute to adverse outcomes like hospital-acquired infections (HAI) through the gut's ability to serve as both a reservoir of HAI pathogens, as well as through pathological microbiome-immune interactions that suppress immune defences against HAI. Consequently, therapeutic strategies to reduce gut enteropathogen colonization have been identified as potentially impactful interventions to reduce hospital-acquired infections and adverse outcomes in patients with critical illness.
Prior clinical trials have employed diverse strategies to modulate the gut microbiome with the objective of reducing adverse outcomes, including large randomized controlled trials of probiotics, or opposing strategies such as digestive decontamination. However, outcomes have been heterogeneous owing to a number of crucial methodological limitations of both the interventions as well as study designs. First, despite proposed mechanisms involving microbiome modulation, none of the important trials have actually analyzed the microbiome to confirm whether their intervention favourably modified the microbiome (i.e. lack of confirmation of biological plausibility). Next, investigations of probiotics have suffered from a lack of rationalized designed for their intended mechanism. For example, the large RCT of probiotics in critically ill patients utilized Lactobacillus rhamnosus GG, yet the choice of this particular probiotic was not based on any prior mechanistic data demonstrating that this species could engraft in the ICU microbiome, nor whether it has the potential to displace enteropathogens from the gut. In fact, very few probiotic trials have ever even determined whether the probiotic strain could engraft into the ICU gut microbiome, nor have any trials determined whether interventions successfully decolonized enteropathogens.
To address these limitations, we will conduct a randomized controlled trial to assess both the safety and biological efficacy (microbiome engraftment and enteropathogen decolonization) of the synbiotic medical nutrition product in critically ill patients. In this phase 1b randomized controlled trial, 64 critically ill patients requiring mechanical ventilation will be randomly assigned to a 21-day course of enteral synbiotic or control (open label). Primary outcome will be safety and biological efficacy of synbiotic engraftment in the gut, with secondary outcome of gut enteropathogen colonization.
1,780 studies on the registry are indexed under Critical Illness; 442 are open to participants now.
This study's planned enrollment of 64 is below the median of 90 across 926 interventional studies indexed under Critical Illness.
Browse Critical Illness studies →University of Calgary is the lead sponsor of 703 studies on the registry; 196 are open to participants now.
Of its 10 completed or terminated interventional studies of FDA-regulated products, 2 (20%) have results posted.
Compared within Critical Illness, the registry's first condition term, which may not be this study's main condition. Counted across the registry records on this site, refreshed daily. How we classify →
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
After a transplant from a donor, the donor’s immune cells attack the recipient’s body, often the skin, gut or liver.
A score of how well the liver works in people with liver disease such as cirrhosis: class A is mild, B moderate and C severe.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
The number of CD4 cells, a type of white blood cell, in a given amount of blood. It is used to follow how well the immune system is doing in HIV.
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GVHD (graft-versus-host disease)
After a transplant from a donor, the donor’s immune cells attack the recipient’s body, often the skin, gut or liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Child-Pugh class
A score of how well the liver works in people with liver disease such as cirrhosis: class A is mild, B moderate and C severe.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
CD4 count
The number of CD4 cells, a type of white blood cell, in a given amount of blood. It is used to follow how well the immune system is doing in HIV.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Absolute neutrophil count (ANC)
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Dietary Supplement: Synbiotic
Standard of care
Other: Standard of Care (SOC)
Synbiotic medical nutrition product consisting of probiotic and prebiotic combination
Standard of care without synbiotic treatment.
Safety - Product-related adverse event rates
Product-related adverse event rates
Time frame: Enrolment to day 90
Biological efficacy
Magnitude of gut microbiome engraftment by synbiotic
Time frame: Enrolment to day 90
Gut enteropathogen colonization
Abundance of enteropathogens in the gut (fecal) microbiome
Time frame: Enrolment to day 90
Plan to share: Yes — Metagenomic gut microbiome sequencing data will be made publicly available at the time of publication of study results.
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Analytic code
Time frame: Available at the time of publication of primary study results.
Access criteria: Publicly accessible.
No publications or documents are linked to this record.
This study is not yet recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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