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

Recruitment & Eligibility

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

Study & Design

Arm && Interventions

Group	Intervention	Description
Placebo	Lactobacillus rhamnosus GG Placebo	Participants in this arm will be given a placebo for 28 days.
LGG Arm	Lactobacillus rhamnosus GG	Participants in this arm will be given LGG for 28 days.

Primary Outcome Measures

Name	Time	Method
Incidence of one or more symptoms of COVID-19 during the study period	60 days	Incidence of one or more symptoms of COVID-19 (fever, chills, headache, muscle aches, runny nose, sore throat, cough, shortness of breath, nausea or vomiting, diarrhea, stomach upset or pain, excessive bloating or gas, constipation, loss of sense of smell, loss of sense of taste, rash, painful toes, or other symptoms related to COVID-19 diagnosis) during the study period

Secondary Outcome Measures

Name	Time	Method
Complications of COVID-19	60 days	Complications of COVID-19 (e.g., need for hospitalization, intubation, mortality) during the study period
Types of symptoms of COVID-19	60 days	Types of symptoms of COVID-19 during the study period (e.g., fever, chills, headache, muscle aches, runny nose, sore throat, cough, shortness of breath, nausea or vomiting, diarrhea, stomach upset or pain, excessive bloating or gas, constipation, loss of sense of smell, loss of sense of taste, rash, painful toes, or other symptoms related to COVID-19 diagnosis)
Duration of symptoms of COVID-19	60 days	Duration of symptoms (days) of COVID-19 during the study period
Incidence of laboratory-confirmed COVID-19 during the study period	60 days	Incidence of laboratory-confirmed COVID-19 (all based on medically-dictated, clinical testing and electronic medical record review) or research laboratory-confirmed COVID-19 (all, based on research testing of nasal swab and stool samples) during the study period

Recruitment & Eligibility