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

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

The purpose of this study is to evaluate the effect of the probiotic Lactobacillus rhamnosus GG (LGG) and the effect of COVID-19 on the microbiome (the microorganisms that live in and on the human body) in exposed household contacts of COVID-19. This is a randomized, double-blind, placebo-controlled study, meaning subjects will be randomly assigned to receive LGG or a placebo (an inactive substance given in the same form as the active substance) and will not know which product they are receiving. Subjects will participate in the study for around 60 days. All subjects must refrain from taking any other probiotics while on study. All subjects must have access to e-mail and the internet to complete study questionnaires. Participation in this study entails taking LGG/placebo for 28 days, responding to questionnaires, and providing stool and nasal swab samples.

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
• Willingness to stop taking other probiotics or to not take any other probiotic while on LGG/placebo (taking a probiotic at the time of screening will not be considered a reason for exclusion. However, subjects will be asked to stop taking their probiotic if they enroll on the study).
• Access to e-mail/internet to complete electronic consent via REDCap

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

• Taking hydroxychloroquine or remdesivir for any reason (as this would have the potential to decrease the expected rate of COVID-19 in this population and affect our power and sample size calculations)

• Enrolled in a COVID-19 prophylaxis study (as this would have the potential to decrease the expected rate of COVID-19 in this population and affect our power and sample size calculations)

• Any medical condition that would prevent taking oral probiotics or increase risks associated with probiotics including but not limited to:

  • Inability to swallow/aspiration risk and no other methods of delivery (e.g., no G/J tube)

  • Increased infection risk due to immunosuppression due to:

    • Chronic immunosuppressive medication
    • Prior organ or hematopoietic stem cell transplant
    • Known neutropenia (ANC <500 cells/ul)
    • HIV and CD4 <200 cells/ul

  • Increased infection risk due to endovascular due to:

    • Rheumatic heart disease
    • Congenital heart defect,
    • Mechanical heart valves
    • Endocarditis
    • Endovascular grafts
    • Permanent endovascular devices such as permanent (not short-term) hemodialysis catheters, pacemakers, or defibrillators

  • Increased infection risk due to mucosal gastrointestinal due to:

    • Gastroesophageal or intestinal injury, including active bleeding