Probiotics use is associated with improved clinical outcomes among hospitalized patients with COVID-19.

Background And Aims: Currently, there are no definitive therapies for coronavirus disease 2019 (COVID-19). Gut microbial dysbiosis has been proved to be associated with COVID-19 severity and probiotics is an adjunctive therapy for COIVD-19. However, the potential benefit of probiotics in COVID-19 has not been studied. We aimed to assess the relationship of probiotics use with clinical outcomes in patients with COVID-19.

Methods: We conducted a propensity-score matched retrospective cohort study of adult patients with COVID-19. Eligible patients received either probiotics plus standard care (probiotics group) or standard care alone (non-probiotics group). The primary outcome was the clinical improvement rate, which was compared among propensity-score matched groups and in the unmatched cohort. Secondary outcomes included the duration of viral shedding, fever, and hospital stay.

Results: Among the propensity-score matched groups, probiotics use was related to clinical improvement rates (log-rank  = 0.028). This relationship was driven primarily by a shorter (days) time to clinical improvement [difference, -3 (-4 to -1),  = 0.022], reduction in duration of fever [-1.0 (-2.0 to 0.0),  = 0.025], viral shedding [-3 (-6 to -1),  < 0.001], and hospital stay [-3 (-5 to -1),  = 0.009]. Using the Cox model with time-varying exposure, use of probiotics remained independently related to better clinical improvement rate in the unmatched cohort.

Conclusion: Our study suggested that probiotics use was related to improved clinical outcomes in patients with COVID-19. Further studies are required to validate the effect of probiotics in combating the COVID-19 pandemic.