Justification: Stimulation of early innate anti-viral responses during the early phase of SARS-COV-2 infection oxygen may improve evolution of illness and late pulmonary complications . This may be possible using a TLR agonist such as a probiotic bacterium possessing desirable immunomodulatory properties .
Method: We performed a non-contact, open-label, prospective randomized clinical trial comparing intranasally applied Lactococcus lactis W136 with saline irrigation alone in patients within 96 hours of diagnosis of SARS-COV-2 infection not requiring supplemental oxygen .
Results: Twenty-three of a planned forty participants aged 18-59 without comorbidities were recruited . Irrigation with intranasal L lactis W136 twice-daily for fourteen days of was associated with a nasal response characterised by increase in the symptom of Facial and Throat pain/discomfort, and with a lesser severity in symptoms of i) Fatigue ii) Olfactory dysfunction and iii) Breathlessness . Safety and tolerability were good, with no acute infections or severe deteriorations . Interpretation: Facial and throat pain may correspond to postulated mechanism of action corresponding to activation of innate defences with antiviral effects and may explain the potentially protective effects seen . Intranasal L lactis W136 irrigations may thus represent a potentially inexpensive, safe, and easily scalable non-antigen based therapeutic for the continuing global SARS-COV-2 pandemic.