DysbiosisNCT05622721
REMBRANDT: REcovery of the MicroBiome fRom Antibiotics for Dental implanTs
An observational study of Dysbiosis and Clostridium Difficile, run by University of Pennsylvania at 1 site in United States.
Trial summary
Antimicrobial therapy can lead to disruption of the gut microbiome and infection with Clostridioides difficile, a disease associated with high morbidity and mortality, particularly among the elderly. Drawing on observations that pet ownership and close contact with pets are protective against colonization with C. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Dysbiosis, Clostridium Difficile, Pet-Human Bonding
- How many people
- 200 participants
- Where
- 1 siteUnited States
- Study dates
- 30 May 2022to 1 May 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: The source population will include patients over 18 years of age receiving prophylactic oral antimicrobials for dental implants at the University of Pennsylvania School of Dental Medicine.
Who may be able to join
- 18 years of age or older.
- Receiving a dental implant.
- Ability to understand study procedures and to comply with them for the entire length of the study.
Who cannot join
- Antimicrobial therapy or hospitalization in the prior three months;
- Any gastrointestinal illness or underlying pathology (e.g., Inflammatory Bowel Disease, gastric ulceration)
- Sustained diarrheal disease (i.e., at least 3 episodes of loose or watery stool per day for 3 or more days) in the prior 3 months;
- Prior history of CDI in the prior year;
- Immunomodulating medication (e.g., tumor necrosis factor inhibitors or systemic steroids) or conditions (e.g., leukemia)
- Inability or unwillingness of individual or legal guardian/representative to give written informed consent.
Trial locations and contacts
1 site in 1 country.
United States1 site
The Robert Schattner Center, University of Pennsylvania, School of Dental Medicine
Philadelphia, Pennsylvania, 19104
About this study
Official title: Impact of Pet Contact on Antimicrobial-associated Dysbiosis and Clostridioides Difficile Infection
Antimicrobial therapy can lead to disruption of the gut microbiome and infection with Clostridioides difficile, a disease associated with high morbidity and mortality, particularly among the elderly. Drawing on observations that pet ownership and close contact with pets are protective against colonization with C. difficile and recurrence of C. difficile infection, the proposed study will test the hypothesis that microbiota that provide colonization resistance against C. difficile are shared between patients and their pets and that pet contact can mitigate antimicrobial-associated gut dysbiosis and the risk of C. difficile infection. This study will further define epidemiologic and pathophysiologic characteristics of C. difficile infection and gut microbiome dysbiosis that could enhance therapeutic options for these conditions, potentially through non-invasive interventions involving animal contact.
Read the detailed description
Clostridioides difficile infection (CDI) is one of the most common causes of healthcare-associated infectious diarrhea and results in significant morbidity and mortality. CDI occurs when the native gut microbiome is disrupted, most often following antimicrobial therapy, and the consequent dysbiosis results in a decrease in microbial diversity, changes in abundance of certain bacterial taxa, and loss of colonization resistance against C. difficile. Restoration of a "functionally intact" gut microbiome is critical to clearing C. difficile, and inadequate restoration can lead to recurrent CDI. The recovery of the gut microbiome from dysbiosis is poorly understood, and factors associated with having and re-gaining a providing colonization resistance against C. difficile are not well known. While animal reservoirs can serve as potential sources of pathogenic bacteria, studies by the candidate and other investigators found that pet ownership protects against colonization and re-infection with C. difficile. Moreover, microbiota are shared between pets and their owners, and the microbiomes of pets contain bacterial taxa that provide colonization resistance against C. difficile. Based on these data, the proposed research will 1) test the hypothesis that the observed protective effects of pet ownership are due to sharing of microbiota that provide colonization resistance against C. difficile between pets and owners; 2) determine whether pet contact mitigates antimicrobial-associated disruption of the gut microbiome and enhances its recovery; and 3) assess whether pet contact decreases the likelihood of colonization and infection with C. difficile following antimicrobial therapy. This will be accomplished though longitudinal sampling of the gut microbiome within the patient/pet unit among patients receiving prophylactic antimicrobials for non-enteric indications (dental implants).
The study will further define epidemiologic and pathophysiologic characteristics of CDI that could enhance therapeutic options for this disease. The underlying premise that animals are a source of protective microbiota rather than a reservoir of C. difficile represents a paradigm shift in CDI epidemiology that may identify animal contact as a novel microbiome-based form of therapy.
- Medical subject headings
- Dysbiosis, Human-Animal Bond, Enterocolitis, Pseudomembranous
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Pet owner | Pet owners | |
| Non pet owner | Non pet owners |
What is being measured
The primary outcome is the main question the study is designed to answer.
Longitudinal change in diversity and composition of the gut microbiota following oral antibiotic prophylaxis
Changes in alpha diversity, beta diversity and composition of the gut microbiome will be ascertained between baseline (prior to taking antibiotics) and 3, 10, 30 and 90 days following the start of the antibiotic regimen
Measured: 90 days
Colonization or infection with C. difficile following antibiotic prophylaxis
The presence of C. difficile in patients' stool will be determined before and 3 days after the beginning of the antibiotic regimen
Measured: 3 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Nov 2022
- Study start30 May 2022
- Primary completion1 Sep 2026
- Study completion1 May 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for DysbiosisStudies of the same condition, open and under way.
- More trials run by University of PennsylvaniaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 200 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Pennsylvania
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Laurel Redding, University of Pennsylvania
- Investigators
- Laurel Redding, VMD, PhD, Principal investigator, University of Pennsylvania
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05622721
- Sponsor's protocol ID
- 844131
- Other IDs
- 1K23AI163351-01A1
- Status last verified
- Oct 2026
- First submitted
- 3 Nov 2022
- Last updated
- 9 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Any data, specimens, forms, reports, video recordings, and other records that leave the site will be identified only by a participant identification number (Participant ID, PID) to maintain confidentiality. All records will be kept in a locked file cabinet. All computer entry and networking programs will be done using PIDs only. Information will not be released without written permission of the participant, except as necessary for monitoring by the IRB or NIAID. Any presentation, abstract, or manuscript will be made available for review by the sponsor and the NIAID prior to submission.
Study at a glance
From the registry record, last updated by the sponsor on 9 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Impact of Pet Contact on Antimicrobial-associated Dysbiosis and Clostridioides Difficile Infection
- ClinicalTrials.gov ID
- NCT05622721
- Acronym / sponsor ID
- 844131
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 200 participants (estimated)
- Lead sponsor
- University of PennsylvaniaUniversity, hospital or other
- Collaborators
- National Institute of Allergy and Infectious Diseases (NIAID)
- Study start
- 30 May 2022 (actual)
- Primary completion
- 1 Sep 2026 (actual)
- Study completion
- 1 May 2027 (estimated)
- First posted
- 21 Nov 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Antimicrobial therapy can lead to disruption of the gut microbiome and infection with Clostridioides difficile, a disease associated with high morbidity and mortality, particularly among the elderly. Drawing on observations that pet ownership and close contact with pets are protective against colonization with C. difficile and recurrence of C. difficile infection, the proposed study will test the hypothesis that microbiota that provide colonization resistance against C. difficile are shared between patients and their pets and that pet contact can mitigate antimicrobial-associated gut dysbiosis and the risk of C. difficile infection. This study will further define epidemiologic and pathophysiologic characteristics of C. difficile infection and gut microbiome dysbiosis that could enhance therapeutic options for these conditions, potentially through non-invasive interventions involving animal contact.
Detailed description
Clostridioides difficile infection (CDI) is one of the most common causes of healthcare-associated infectious diarrhea and results in significant morbidity and mortality. CDI occurs when the native gut microbiome is disrupted, most often following antimicrobial therapy, and the consequent dysbiosis results in a decrease in microbial diversity, changes in abundance of certain bacterial taxa, and loss of colonization resistance against C. difficile. Restoration of a "functionally intact" gut microbiome is critical to clearing C. difficile, and inadequate restoration can lead to recurrent CDI. The recovery of the gut microbiome from dysbiosis is poorly understood, and factors associated with having and re-gaining a providing colonization resistance against C. difficile are not well known. While animal reservoirs can serve as potential sources of pathogenic bacteria, studies by the candidate and other investigators found that pet ownership protects against colonization and re-infection with C. difficile. Moreover, microbiota are shared between pets and their owners, and the microbiomes of pets contain bacterial taxa that provide colonization resistance against C. difficile. Based on these data, the proposed research will 1) test the hypothesis that the observed protective effects of pet ownership are due to sharing of microbiota that provide colonization resistance against C. difficile between pets and owners; 2) determine whether pet contact mitigates antimicrobial-associated disruption of the gut microbiome and enhances its recovery; and 3) assess whether pet contact decreases the likelihood of colonization and infection with C. difficile following antimicrobial therapy. This will be accomplished though longitudinal sampling of the gut microbiome within the patient/pet unit among patients receiving prophylactic antimicrobials for non-enteric indications (dental implants).
The study will further define epidemiologic and pathophysiologic characteristics of CDI that could enhance therapeutic options for this disease. The underlying premise that animals are a source of protective microbiota rather than a reservoir of C. difficile represents a paradigm shift in CDI epidemiology that may identify animal contact as a novel microbiome-based form of therapy.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Pet owner | – | –Pet owners |
| Non pet owner | – | –Non pet owners |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- The source population will include patients over 18 years of age receiving prophylactic oral antimicrobials for dental implants at the University of Pennsylvania School of Dental Medicine.
Key inclusion criteria (3 listed)
- 18 years of age or older.
- Receiving a dental implant.
- Ability to understand study procedures and to comply with them for the entire length of the study.
Key exclusion criteria (6 listed)
- Antimicrobial therapy or hospitalization in the prior three months;
- Any gastrointestinal illness or underlying pathology (e.g., Inflammatory Bowel Disease, gastric ulceration)
- Sustained diarrheal disease (i.e., at least 3 episodes of loose or watery stool per day for 3 or more days) in the prior 3 months;
- Prior history of CDI in the prior year;
- Immunomodulating medication (e.g., tumor necrosis factor inhibitors or systemic steroids) or conditions (e.g., leukemia)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Longitudinal change in diversity and composition of the gut microbiota following oral antibiotic prophylaxis
Time frame: 90 days
Changes in alpha diversity, beta diversity and composition of the gut microbiome will be ascertained between baseline (prior to taking antibiotics) and 3, 10, 30 and 90 days following the start of the antibiotic regimen
Colonization or infection with C. difficile following antibiotic prophylaxis
Time frame: 3 days
The presence of C. difficile in patients' stool will be determined before and 3 days after the beginning of the antibiotic regimen
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Oct 2026.
- Individual participant dataSharing planned: No. Any data, specimens, forms, reports, video recordings, and other records that leave the site will be identified only by a participant identification number (Participant ID, PID) to maintain confidentiality. All records will be kept in a locked file cabinet. All computer entry and networking programs will be done using PIDs only. Information will not be released without written permission of the participant, except as necessary for monitoring by the IRB or NIAID. Any presentation, abstract, or manuscript will be made available for review by the sponsor and the NIAID prior to submission.
Related trials for Dysbiosis
Recruiting
Colon-delivered Riboflavin and Gut Microbiota Composition
Microbiome Dysbiosis, Gut Health
Enrolling by invitationPhase 2
Herbal Supplement (Biocidin REMOVE) for Bacterial Overgrowth in Irritable Bowel Syndrome
Irritable Bowel Syndrome (IBS), Small Intestinal Bacterial Overgrowth Syndrome (SIBO)
RecruitingObservational study
Effects Of Periodontal Therapy In Patients With Inflammatory Bowel Disease
Periodontal Diseases, IBD
Recruiting
Effect of a Probiotic or Postbiotic on Gut Microbiome During Antibiotic Treatment
Microbiome
RecruitingObservational study
Metabolic and Functional Study of γδ T Cells in Critically Ill Patients
Sepsis, Critical Illness
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Laurel Redding, VMD, PhD principal investigator
University of Pennsylvania
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Dysbiosis and Clostridium Difficile, run by University of Pennsylvania at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 9 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Longitudinal change in diversity and composition of the gut microbiota following oral antibiotic prophylaxis (time frame: 90 days). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Oct 2026.