Effect of Lactobacillus on the Microbiome of Household Contacts Exposed to COVID-19

PROTECT-EHC: Probiotics To Eliminate COVID-19 Transmission in Exposed Household Contacts

Sponsored by Duke University

Dr. Anthony Sung and Dr. Paul Wischmeyer at Duke University are looking for people to join their PROTECT-EHC study. Exposed household contacts (EHC) are people who live with someone with COVID-19 and therefore have an increased chance of contracting the virus.

We are doing this study is to see if taking a probiotic for 28 days can change the microbiome, or bacteria in the gut and nose. Participation could provide direct benefit as changing the microbiome with our probiotic may reduce symptomatic COVID-19 by 30-50%.


Coronavirus disease 2019 (COVID-19) is a respiratory illness that can spread from person to person. The virus that causes COVID-19 is a novel coronavirus that was first identified during an investigation into an outbreak in Wuhan, China.

How is this study designed?

Study Type: Interventional (Clinical Trial) Estimated Enrollment: 1000 participants Primary Purpose: Basic Science Actual Study Start Date: June 24, 2020 Estimated Study Completion Date: May 25, 2022

Who is this study for?

Inclusion Criteria*:

  • Age >=1 year (as children <1 year may not be able to take oral probiotics)
  • Household contact of someone diagnosed with COVID-19

Exclusion Criteria*:

  • Symptoms of COVID-19 at enrollment, including:
    • Fever
    • Respiratory symptoms
    • GI symptoms
    • Anosmia
    • Ageusia ->7 days since original patient associated with household contact was diagnosed with COVID-19

*Other criteria apply. Please speak with the study team for more information.

What should I expect?

Study supplies will be shipped overnight to your address

  • Day 1: AFTER collecting your baseline stool and nasal samples and online surveys, you may start taking study tablets (follow instructions to take study tablets DAILY)
  • Day 28: You will receive an email with a link to complete online surveys. Collect stool and nasal samples (see Instructions for Collection). Mail back samples (see Instructions for Mailing Samples Back to Duke)
  • Day 60: You will receive an email with a link to complete online surveys

Participate in the PROTECT-EHC study

Thank you for your interest in advancing COVID-19 research.

Please fill out this contact form to be connected to a member of the study team. The following information that you enter will only be authorized to be shared with the research team conducting this specific study.

If you have any difficulties or questions, please contact our support specialists at [email protected]

Have questions or need help?

For general questions about COVID-19 clinical trials, please email [email protected] For study specific inquiries, submit the interest form and you'll be connected to the team.