inclusion criteria: * aged between 18 to 79 (inclusive) * have mild to moderate covid-19-like symptoms based on the symptom list from cdc (updated may 13, 2020) and the severity categorization from fda \[18\]: a) mild covid-19 * fever or chills, cough, shortness of breath or difficulty breathing, fatigue, muscle or body aches, headache, new loss of taste or smell, sore throat, congestion or runny nose, nausea or vomiting, and diarrhea * no clinical signs indicative of moderate, severe, or critical illness severity b) moderate covid-19 * symptoms of moderate illness with covid-19 could include any symptom of mild illness or shortness of breath with exertion * clinical signs suggestive of moderate illness with covid-19, such as respiratory rate ≥ 20 breaths/min, oxygen saturation level \> 93% on room air at sea level, heart rate ≥ 90 beats/min * no clinical signs indicative of severe or critical illness severity * directed to home isolation by study physician * confirm study enrollment within 7 days of symptom onset * practice acceptable contraception, i.e., continue with current methods if participants are already practicing contraception, otherwise participants must agree to practicing contraception with a barrier method (male or female condom) or abstinence, from day 1 to day 35 or 7 days after the last dose of nbt-nm108 if they do not complete the 28-day intervention. * have access to a smartphone, tablet, computer, or other qualifying internet-enabled device and daily internet access * understand and be able to follow written and oral instructions in english * provide informed consent exclusion criteria * have tested positive for covid-19 and recovered * receiving vancomycin monotherapy or oral broad-spectrum antibiotics * inability to receive oral fluids * self-reported allergy or intolerance to any ingredients in nbt-nm108 * surgery involving the intestinal lumen within the last 30 days * documented diagnosis of celiac disease, inflammatory bowel disease or irritable bowel syndrome * pregnancy or breastfeeding * bariatric surgery * immunocompromised, e.g., cancer treatment, bone marrow/organ transplant, immune deficiency, poorly controlled hiv/aids, prolonged use of steroids or other immunosuppressant medications

inclusion criteria: * aged between 18 to 79 (inclusive) * have mild to moderate covid-19-like symptoms based on the symptom list from cdc (updated may 13, 2020) and the severity categorization from fda \[18\]: a) mild covid-19 * fever or chills, cough, shortness of breath or difficulty breathing, fatigue, muscle or body aches, headache, new loss of taste or smell, sore throat, congestion or runny nose, nausea or vomiting, and diarrhea * no clinical signs indicative of moderate, severe, or critical illness severity b) moderate covid-19 * symptoms of moderate illness with covid-19 could include any symptom of mild illness or shortness of breath with exertion * clinical signs suggestive of moderate illness with covid-19, such as respiratory rate ≥ 20 breaths/min, oxygen saturation level \> 93% on room air at sea level, heart rate ≥ 90 beats/min * no clinical signs indicative of severe or critical illness severity * directed to home isolation by study physician * confirm study enrollment within 7 days of symptom onset * practice acceptable contraception, i.e., continue with current methods if participants are already practicing contraception, otherwise participants must agree to practicing contraception with a barrier method (male or female condom) or abstinence, from day 1 to day 35 or 7 days after the last dose of nbt-nm108 if they do not complete the 28-day intervention. * have access to a smartphone, tablet, computer, or other qualifying internet-enabled device and daily internet access * understand and be able to follow written and oral instructions in english * provide informed consent exclusion criteria * have tested positive for covid-19 and recovered * receiving vancomycin monotherapy or oral broad-spectrum antibiotics * inability to receive oral fluids * self-reported allergy or intolerance to any ingredients in nbt-nm108 * surgery involving the intestinal lumen within the last 30 days * documented diagnosis of celiac disease, inflammatory bowel disease or irritable bowel syndrome * pregnancy or breastfeeding * bariatric surgery * immunocompromised, e.g., cancer treatment, bone marrow/organ transplant, immune deficiency, poorly controlled hiv/aids, prolonged use of steroids or other immunosuppressant medications

inclusion criteria: - aged between 18 to 79 (inclusive) - have mild to moderate covid-19-like symptoms based on the symptom list from cdc (updated may 13, 2020) and the severity categorization from fda [18]: a) mild covid-19 - fever or chills, cough, shortness of breath or difficulty breathing, fatigue, muscle or body aches, headache, new loss of taste or smell, sore throat, congestion or runny nose, nausea or vomiting, and diarrhea - no clinical signs indicative of moderate, severe, or critical illness severity b) moderate covid-19 - symptoms of moderate illness with covid-19 could include any symptom of mild illness or shortness of breath with exertion - clinical signs suggestive of moderate illness with covid-19, such as respiratory rate ≥ 20 breaths/min, oxygen saturation level > 93% on room air at sea level, heart rate ≥ 90 beats/min - no clinical signs indicative of severe or critical illness severity - directed to home isolation by study physician - confirm study enrollment within 7 days of symptom onset - practice acceptable contraception, i.e., continue with current methods if participants are already practicing contraception, otherwise participants must agree to practicing contraception with a barrier method (male or female condom) or abstinence, from day 1 to day 35 or 7 days after the last dose of nbt-nm108 if they do not complete the 28-day intervention. - have access to a smartphone, tablet, computer, or other qualifying internet-enabled device and daily internet access - understand and be able to follow written and oral instructions in english - provide informed consent exclusion criteria - have tested positive for covid-19 and recovered - receiving vancomycin monotherapy or oral broad-spectrum antibiotics - inability to receive oral fluids - self-reported allergy or intolerance to any ingredients in nbt-nm108 - surgery involving the intestinal lumen within the last 30 days - documented diagnosis of celiac disease, inflammatory bowel disease or irritable bowel syndrome - pregnancy or breastfeeding - bariatric surgery - immunocompromised, e.g., cancer treatment, bone marrow/organ transplant, immune deficiency, poorly controlled hiv/aids, prolonged use of steroids or other immunosuppressant medications

inclusion criteria: - aged between 18 to 79 (inclusive) - have mild to moderate covid-19-like symptoms based on the symptom list from cdc (updated may 13, 2020) and the severity categorization from fda [18]: a) mild covid-19 - fever or chills, cough, shortness of breath or difficulty breathing, fatigue, muscle or body aches, headache, new loss of taste or smell, sore throat, congestion or runny nose, nausea or vomiting, and diarrhea - no clinical signs indicative of moderate, severe, or critical illness severity b) moderate covid-19 - symptoms of moderate illness with covid-19 could include any symptom of mild illness or shortness of breath with exertion - clinical signs suggestive of moderate illness with covid-19, such as respiratory rate ≥ 20 breaths/min, oxygen saturation level > 93% on room air at sea level, heart rate ≥ 90 beats/min - no clinical signs indicative of severe or critical illness severity - directed to home isolation by study physician - confirm study enrollment within 7 days of symptom onset - practice acceptable contraception, i.e., continue with current methods if participants are already practicing contraception, otherwise participants must agree to practicing contraception with a barrier method (male or female condom) or abstinence, from day 1 to day 35 or 7 days after the last dose of nbt-nm108 if they do not complete the 28-day intervention. - have access to a smartphone, tablet, computer, or other qualifying internet-enabled device and daily internet access - understand and be able to follow written and oral instructions in english - provide informed consent exclusion criteria - have tested positive for covid-19 and recovered - receiving vancomycin monotherapy or oral broad-spectrum antibiotics - inability to receive oral fluids - self-reported allergy or intolerance to any ingredients in nbt-nm108 - surgery involving the intestinal lumen within the last 30 days - documented diagnosis of celiac disease, inflammatory bowel disease or irritable bowel syndrome - pregnancy or breastfeeding - bariatric surgery - immunocompromised, e.g., cancer treatment, bone marrow/organ transplant, immune deficiency, poorly controlled hiv/aids, prolonged use of steroids or other immunosuppressant medications

inclusion criteria: - aged between 18 to 69 (inclusive) - have prediabetes or t2dm - have mild to moderate covid-19-like symptoms based on the symptom list from the cdc (updated may 13, 2020) and the severity categorization from fda (20): 1. mild covid-19 - fever or chills, cough, shortness of breath or difficulty breathing, fatigue, muscle or body aches, headache, new loss of taste or smell, sore throat, congestion or runny nose, nausea or vomiting, and diarrhea - no clinical signs indicative of moderate, severe, or critical illness severity 2. moderate covid-19 - symptoms of moderate illness with covid-19 could include any symptom of mild illness or shortness of breath with exertion - clinical signs suggestive of moderate illness with covid-19, such as respiratory rate ≥ 20 breaths/min, oxygen saturation level > 93% on room air at sea level, heart rate ≥ 90 beats/min - no clinical signs indicative of severe or critical illness severity - directed to home isolation by the study physician - confirm study enrollment within 4 days of symptoms onset - practice acceptable contraception, i.e., continue with current methods if participants are already practicing contraception, otherwise, participants must agree to practice contraception with a barrier method (male or female condom) or abstinence, from day 0 to day 35 or 7 days after the last dose of nbt-nm108 if they do not complete the 28-day intervention. - have access to a smartphone, tablet, computer, or other qualifying internet-enabled device and daily internet access - understand and be able to follow written and oral instructions in english - provide informed consent exclusion criteria - have received a covid-19 vaccine or plan to be vaccinated before enrollment - have tested positive for covid-19 and recovered - receiving remdesivir or baricitinib for medical conditions not related to covid-19 - receiving vancomycin monotherapy or oral broad-spectrum antibiotics - inability to receive oral fluids - self-reported allergy or intolerance to any ingredients in nbt-nm108 - surgery involving the intestinal lumen within the last 30 days - documented diagnosis of celiac disease, inflammatory bowel disease or irritable bowel syndrome - pregnancy or breastfeeding - bariatric surgery - chronic lung disease or moderate/severe asthma - heart failure, coronary artery disease, congenital heart disease, cardiomyopathies or pulmonary hypertension - chronic kidney disease on dialysis - chronic liver disease (cirrhosis) - immunocompromised, e.g. cancer treatment, bone marrow/organ transplant, immune deficiency, poorly controlled hiv/aids, prolonged use of steroids or other immunosuppressant medications

inclusion criteria: - aged between 18 to 69 (inclusive) - have prediabetes or t2dm - have mild to moderate covid-19-like symptoms based on the symptom list from the cdc (updated may 13, 2020) and the severity categorization from fda (20): 1. mild covid-19 - fever or chills, cough, shortness of breath or difficulty breathing, fatigue, muscle or body aches, headache, new loss of taste or smell, sore throat, congestion or runny nose, nausea or vomiting, and diarrhea - no clinical signs indicative of moderate, severe, or critical illness severity 2. moderate covid-19 - symptoms of moderate illness with covid-19 could include any symptom of mild illness or shortness of breath with exertion - clinical signs suggestive of moderate illness with covid-19, such as respiratory rate ≥ 20 breaths/min, oxygen saturation level > 93% on room air at sea level, heart rate ≥ 90 beats/min - no clinical signs indicative of severe or critical illness severity - directed to home isolation by the study physician - confirm study enrollment within 4 days of symptoms onset - practice acceptable contraception, i.e., continue with current methods if participants are already practicing contraception, otherwise, participants must agree to practice contraception with a barrier method (male or female condom) or abstinence, from day 0 to day 35 or 7 days after the last dose of nbt-nm108 if they do not complete the 28-day intervention. - have access to a smartphone, tablet, computer, or other qualifying internet-enabled device and daily internet access - understand and be able to follow written and oral instructions in english - provide informed consent exclusion criteria - have received a covid-19 vaccine or plan to be vaccinated before enrollment - have tested positive for covid-19 and recovered - receiving remdesivir or baricitinib for medical conditions not related to covid-19 - receiving vancomycin monotherapy or oral broad-spectrum antibiotics - inability to receive oral fluids - self-reported allergy or intolerance to any ingredients in nbt-nm108 - surgery involving the intestinal lumen within the last 30 days - documented diagnosis of celiac disease, inflammatory bowel disease or irritable bowel syndrome - pregnancy or breastfeeding - bariatric surgery - chronic lung disease or moderate/severe asthma - heart failure, coronary artery disease, congenital heart disease, cardiomyopathies or pulmonary hypertension - chronic kidney disease on dialysis - chronic liver disease (cirrhosis) - immunocompromised, e.g. cancer treatment, bone marrow/organ transplant, immune deficiency, poorly controlled hiv/aids, prolonged use of steroids or other immunosuppressant medications

inclusion criteria: - aged between 18 to 69 (inclusive) - have prediabetes or t2dm - have mild to moderate covid-19-like symptoms based on the symptom list from the cdc (updated may 13, 2020) and the severity categorization from fda (20): 1. mild covid-19 - fever or chills, cough, shortness of breath or difficulty breathing, fatigue, muscle or body aches, headache, new loss of taste or smell, sore throat, congestion or runny nose, nausea or vomiting, and diarrhea - no clinical signs indicative of moderate, severe, or critical illness severity 2. moderate covid-19 - symptoms of moderate illness with covid-19 could include any symptom of mild illness or shortness of breath with exertion - clinical signs suggestive of moderate illness with covid-19, such as respiratory rate ≥ 20 breaths/min, oxygen saturation level > 93% on room air at sea level, heart rate ≥ 90 beats/min - no clinical signs indicative of severe or critical illness severity - directed to home isolation by the study physician - confirm study enrollment within 4 days of symptoms onset - practice acceptable contraception, i.e., continue with current methods if participants are already practicing contraception, otherwise, participants must agree to practice contraception with a barrier method (male or female condom) or abstinence, from day 0 to day 35 or 7 days after the last dose of nbt-nm108 if they do not complete the 28-day intervention. - have access to a smartphone, tablet, computer, or other qualifying internet-enabled device and daily internet access - understand and be able to follow written and oral instructions in english - provide informed consent

inclusion criteria: - aged between 18 to 69 (inclusive) - have prediabetes or t2dm - have mild to moderate covid-19-like symptoms based on the symptom list from the cdc (updated may 13, 2020) and the severity categorization from fda (20): 1. mild covid-19 - fever or chills, cough, shortness of breath or difficulty breathing, fatigue, muscle or body aches, headache, new loss of taste or smell, sore throat, congestion or runny nose, nausea or vomiting, and diarrhea - no clinical signs indicative of moderate, severe, or critical illness severity 2. moderate covid-19 - symptoms of moderate illness with covid-19 could include any symptom of mild illness or shortness of breath with exertion - clinical signs suggestive of moderate illness with covid-19, such as respiratory rate ≥ 20 breaths/min, oxygen saturation level > 93% on room air at sea level, heart rate ≥ 90 beats/min - no clinical signs indicative of severe or critical illness severity - directed to home isolation by the study physician - confirm study enrollment within 4 days of symptoms onset - practice acceptable contraception, i.e., continue with current methods if participants are already practicing contraception, otherwise, participants must agree to practice contraception with a barrier method (male or female condom) or abstinence, from day 0 to day 35 or 7 days after the last dose of nbt-nm108 if they do not complete the 28-day intervention. - have access to a smartphone, tablet, computer, or other qualifying internet-enabled device and daily internet access - understand and be able to follow written and oral instructions in english - provide informed consent