# Impact of pet contact on antimicrobial-associated dysbiosis and Clostridioides difficile infection

> **NIH NIH K23** · UNIVERSITY OF PENNSYLVANIA · 2022 · $179,426

## Abstract

PROJECT SUMMARY
 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 microbiome capable of
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 older than 60 years (i.e., at greatest risk of CDI) 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. The proposed study will form a
foundation for an independent career in patient-oriented research dedicated to understanding and mitigating
antimicrobial-associated dysbiosis and CDI. The candidate will acquire experience in directing a large,
observational microbiome study and essential training in the advanced statistical and bioinformatics methods
necessary to analyze the interaction between patient-level factors and microbial ecology. The research
proposal is paired with a career development plan that makes use of the extensive resources of the University
of Pennsylvania and that capitalizes on a superlative m...

## Key facts

- **NIH application ID:** 10449436
- **Project number:** 1K23AI163351-01A1
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **Principal Investigator:** Laurel Elizabeth Redding
- **Activity code:** K23 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $179,426
- **Award type:** 1
- **Project period:** 2022-03-09 → 2027-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10449436

## Citation

> US National Institutes of Health, RePORTER application 10449436, Impact of pet contact on antimicrobial-associated dysbiosis and Clostridioides difficile infection (1K23AI163351-01A1). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10449436. Licensed CC0.

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