A series of microbiota were correlated inversely with the disease severity and virus load. Gut microbiota could play a role in modulating host immune response and potentially influence disease severity and outcomes.

Coronavirus can target multiple organs due to the hyperactive immune response with cytokine storms. Several studies have detected SARS-CoV-2 in stool samples and indicated that the virus could spread via faeces. Importantly, COVID-19 uses the same receptor as SARS and this doorway can also be found in the intestine. The cell entry receptor, known as angiotensin converting enzyme 2 (ACE2) receptor mediate entry of SARS-CoV-2 and is highly expressed in small bowel enterocytes. ACE2 is important in controlling intestinal inflammation and its disruption may lead to diarrhoea. In our previous study, stool samples from 15 patients with COVID-19 were analysed. Depleted symbionts and gut dysbiosis were noted even after patients were detected negative of SARS-CoV-2. A series of microbiota were correlated inversely with the disease severity and virus load. Gut microbiota could play a role in modulating host immune response and potentially influence disease severity and outcomes.

In July 2020, there are more than 15 billion confirmed cases globally with 620 thousand deaths. Currently, there are more than 2000 confirmed cases of COVID-19 in Hong Kong. It is important to rebalance the gut microbiota in COVID-19 patients and to improve the symptoms and the quality of life of these patients.

Inclusion Criteria:

1. Aged 18 or above; and
2. A confirmed diagnosis of SARS-Cov.2 infection using the PCR according to the standard of according to Centre for Health Protection, Department of Health, HK and released from isolation at recruitment.
3. Written informed consent obtained

Exclusion Criteria:

1. Known allergy or intolerance to the intervention product or its components

2. Any known 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)

3. Known increased infection risk due to immunosuppression such as:

   • Prior organ or hematopoietic stem cell transplant
   • Neutropenia (ANC <500 cells/ul)
   • HIV and CD4 <200 cells/ul

4. Known 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

5. Documented pregnancy