"CHANGE COVID-19 Severity"

We are conducting an investigator-initiated, single center, blinded, placebo-controlled, randomized clinical trial evaluating magnesium citrate combined with a probiotic for the treatment of adults hospitalized with COVID-19.

We are conducting an investigator-initiated, single center, blinded, placebo-controlled, randomized clinical trial evaluating magnesium citrate combined with a probiotic for the treatment of adults hospitalized with COVID-19. Patients, treating clinicians, and study personnel will all be blinded to study group assignment.

This research study is being done to determine if taking oral magnesium citrate and a probiotic will improve the outcome of adults hospitalized with COVID-19. In this study, half of the participants will receive magnesium citrate plus a probiotic and half will receive a placebo randomized 1:1. You will be placed in one of these 2 groups randomly, like the flip of a coin. The investigational arm will receive one 10 oz. bottle of magnesium citrate to drink once and 2 oral probiotic capsules to be taken twice a day for 6 days. We will also collect a blood sample on Day 1 and Day 7 for CD4+ and CD8+ evaluation and will be collecting data on each participants COVID-19 infection progression during hospitalization.

Assessments for this study will be done on day 7 and day 29 if the participant is still hospitalized at those time points. If they have been discharged from the hospital before these assessments, we will do these by phone. Each participant will also be contacted at 3 months to assess how they are doing. There will be no compensation for taking part in this study.

Eligibility Criteria:
Inclusion Criteria:

1. Age ≥18 years
2. Currently hospitalized or in an emergency department with anticipated hospitalization.
3. Symptoms of acute respiratory infection, defined as one or more of the following:

   1. Cough
   2. Fever (\> 37.5° C / 99.5° F)
   3. Shortness of breath (operationalized as any of the following: subjective shortness of breath reported by patient or surrogate; tachypnea with respiratory rate ≥22 /minute; hypoxemia, defined as SpO2 \<92% on room air, new receipt of supplemental oxygen to maintain SpO2 ≥92%, or increased supplemental oxygen to maintain SpO2 ≥92% for a patient on chronic oxygen therapy).
   4. Sore throat
   5. Anosmia
4. Laboratory-confirmed SARS (Severe acute respiratory syndrome-Coronavirus 2 (SARS CoV-2) infection within 10 days prior to randomization
5. Ability to manage own stool care

Exclusion Criteria:

1. Prisoner
2. Pregnancy
3. Breast feeding
4. Current infectious or noninfectious diarrheal illness
5. Unable to randomize within 21 days after onset of acute respiratory infection symptoms
6. Unable to randomize after hospital arrival
7. Colonic obstruction
8. Unresolved hypovolemia
9. CrCl \<30ml/min
10. Hypermagnesemia
11. Diagnosis of Long QT syndrome
12. Known allergy to magnesium citrate or probiotic
13. Unresolved electrolyte imbalance such as hypokalemia or hypocalcemia. The patient can be enrolled if electrolytes are corrected and sustained.
14. Receipt of \>1 dose of magnesium citrate or any other colonic cleanser in the 7 days prior to enrollment
15. Inability to receive enteral medications
16. Refusal or inability to be contacted on Day 15 for clinical outcome assessment if discharged prior to Day 15
17. Concurrent medical illness that interferes with clinical assessment Previous enrollment in this trial
18. The treating clinical team does not believe equipoise exists regarding the use of magnesium citrate plus a probiotic for the treatment of this patient.
19. Participating in any other COVID-19 therapeutic trial
20. Allergic to soy.
21. Lactose intolerant.