Oropharyngeal Probiotic ENT-K12 Prevents Respiratory Tract Infections Among Frontline Medical Staff Fighting Against COVID-19

Source: Front. Bioeng. Biotechnol., 24 June 2021.

Healthcare workers at the frontline are facing a substantial risk of respiratory tract infection during the COVID-19 outbreak due to an extremely stressful work schedule and public health event. A well-established first-line defense on oropharyngeal microbiome could be a promising strategy to protect individuals from respiratory tract infections including COVID-19. The most thoroughly studied oropharyngeal probiotic product which creates a stable upper respiratory tract microbiota capable of preventing upper respiratory tract infections was chosen to evaluate the safety and efficacy on reducing episodes of upper respiratory tract infections for COVID-19 healthcare workers.

Purpose: To our knowledge to date, this is the very first study describing the beneficial effects of oropharyngeal probiotic been administered by healthcare workers during the COVID-19 pandemic.

Materials and methods: The multicenter, open, randomized controlled clinical trial was conducted on 200 frontline medical staff enrolled in Wuhan, China, and treated between March 5, 2020 and April 5, 2020. All the enrolled individuals were healthy doctors and nurses 20–65 years of age and work in close contact with hospitalized COVID-19 patients. We provided the probiotics ENT-K12 to frontline medical staff for prophylactic use on a daily basis.

Results:Our finding suggests that oropharyngeal probiotic administration significantly reduced the incidence of respiratory tract infections by 64.8%, reduced the time experiencing respiratory tract infections and oral ulcer symptoms by 78%, shortened the days absent from work by 95.5%, and reduced the time under medication where there is no record of antibiotic and anti-viral drug intake in the probiotic group. Furthermore, medical staff treated with Bactoblis experienced sustained protection from respiratory tract infections since the 10th day of oropharyngeal probiotic administration resulting in an extremely low incidence rate of respiratory tract infections.


The oropharyngeal probiotic ENT-K12 can be a valid solution in the prevention of respiratory tract infections.