Abstract:
Background A number of laboratory data and clinical studies have shown that probiotic bacteria may be benefcial
in respiratory viral diseases. We investigated the role of probiotics in coronavirus disease-19 (COVID -19), post-disease
symptoms, and humoral immune responses to viral antigens.
Methods This was a randomized, double-blind, placebo-controlled, prospective, multicenter study. We included
symptomatic patients aged 18–65 years without risk of severe disease, and positive antigen/PCR test for SARS-CoV-2.
Patients received (Bifdobacterium (B.) lactis BI040, B. longum BL020, Lactobacillus (L) rhamnosus LR110, L. casei LC130, L.
acidophilus LA120, 5 billion CFU total) or placebo 1 capsule a day for 28 days and recorded symptoms. Three months
later patients completed Post-COVID-19 Questionnaire (PCQ-19). On days 0–5 and 28–35, blood was sampled for IgG
to nucleocapsid protein (NCP) and receptor binding domain (RBD)/spike 1 (S1) protein. The primary outcome measure was a patient global symptom score on day 10 of observation. The diference between groups was assessed using
the Mann–Whitney U test.
Results Seventy-three patients were assessed for clinical endpoints and 44 patients were evaluated for antibody
production. At day 10, the median global symptom score (interquartile range) was lower in the probiotic group (0.0
(0.0–2.0) vs. 2.0 (1.0–5.0), P<0.05). The probiotic group had a shorter duration of fatigue and anxiety after COVID -19
(P<0.05) and a greater change in IgG concentration on RBD/S1 (225.9 vs. 105.6 binding antibody units/mL, P<0.05).
Conclusions Use of probiotics alleviates acute and post-disease symptoms, and improves humoral immune
response to viral antigens.
