* 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

* 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

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

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

- 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 remdesevir 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

- 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 remdesevir 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