Table 1.
Ongoing clinical trials testing the effectiveness of gut microbiota modulation in patients with COVID-19 (ClinicalTrials.gov).
| Registration | Country | Study design | Evaluation | Target subjects | Intervention | Administration route | Duration | Participants (number) |
|---|---|---|---|---|---|---|---|---|
| NCT04458519 | Canada | Randomized single-blind, prospective clinical trial |
Influence on severity of symptoms | Mild–moderate non-hospitalized COVID-19 patients (18–59 years) |
Lactococcus lactis W136, (2.4 x 109 CFU) |
Intranasal (twice-daily) |
14 days | 40 |
| NCT04390477 | Spain | Randomized open-label, prospective case-control clinical trial | Influence on symptoms, hospitalization duration, and virus clearance | Moderate–severe hospitalized COVID-19 patients (≥ 18 years) |
Probiotic strain not informed, (1 x 109 CFU) |
Orally (daily capsule) |
30 days | 40 |
| NCT04366180 | Spain | Randomized quadruple-blinded, multicentric clinical trial |
Influence on the incidence and severity of COVID-19 | Health workers exposed to the virus (≥ 20 years) |
Lactobacillus K8 strain (3 x 109 CFU) |
Orally (daily capsule) |
2 months | 314 |
| NCT04517422 | Mexico | Randomized quadruple-blinded, controlled clinical trial |
Influence on disease progression, GIT symptoms, microbiota, viral load, IgG/IgM | Mild-symptomatic COVID-19 patients, SpO2 > 90% (18–60 years) |
L. plantarum CECT7481, CECT 7484, CECT 7485, Pediococcus acidilactici CECT 7483 |
Orally (daily capsule) |
30 days | 300 |
| NCT04366089 | Italy | Randomized single-blind, prospective clinical trial |
Influence on disease progression, hospitalization in intensive care units |
Hospitalized COVID-19 patients (≥ 18 years) |
Oxygen ozone therapy plus B. lactis DSM 32246, 32247, L. acidophilus DSM 32241, L. helveticus DSM 32242, L. paracasei DSM 32243, L. plantarum DSM 32244, L. brevis DSM 27961 (2 x 109 CFU) |
Orally (six sachets/ twice-daily) |
7 days | 152 |
| NCT04462627 | Belgium | Non-randomized, open label clinical trial |
Influence on COVID-19 transmission to health care professionals | COVID-19 positive patients and healthy volunteers (≥ 18 years) |
L. acidophilus NCFM B. lactis Bi-07 (12.5 x 109 CFU) |
Orally | 4 days | 500 |
| NCT04399252 | United States of America | Randomized double-blind placebo-controlled clinical trial | Influence on the gut microbiome | Exposed household contacts of COVID-19 patients (≥ 1 year) |
Lactobacillus rhamnosus GG | Orally (two capsules/day) |
28 days | 1,000 |
| NCT04507867 | Mexico | Randomized single-blind controlled- clinical trial |
Influence on disease progression, reduction of comorbidities’ complications |
Hospitalized COVID-19 patients | Nutritional support system (NSS) plus Saccharomyces bourllardii (250 mg) |
Orally (two capsules/day) |
6 days | 240 |
| NCT04403646 | Argentina | Randomized triple-blind controlled- clinical trial |
Influence on gut microbiota modulation | Hospitalized COVID-19 positive patients (≥ 18 years) |
Dry extract polyphenols (tannins)240 mg B12 vitamin 0.72 µg |
Orally (two capsules/day) |
14 days | 140 |
| NCT04540406 | United States of America | Randomized open-label, controlled clinical trial | Influence on gut microbiota, early treatment of suspected or confirmed COVID-19 in prediabetes or T2D patients |
Mild-moderate COVID-19 patients, prediabetes or T2D patients (18–69 years) |
NBT-NM108, a novel botanical-based fixed-combination drug (30 g) | Orally (4 times-daily) |
28 days | 100 |
COVID-19, Coronavirus disease; CFU, colony forming unit; GIT, gastrointestinal tract; T2D, type 2 diabetes; SpO2, oxygen saturation.